KR20160094550A - Novel fusion protein comprising scFv and ferritin and uses thereof - Google Patents

Abstract

The present invention relates to a fusion protein comprising a single chain antibody fragment (scFv) and a ferritin-bound fusion protein, a polynucleotide encoding the fusion protein, an expression vector comprising the polynucleotide, a transformant into which the expression vector is introduced, A method for producing the fusion protein from the transformant, a nanocluster containing the fusion protein, a drug carrier containing the nanocluster, a diagnostic kit, a protein chip, and an antigen detection method using the nanocluster . The present invention relates to a method for producing a fusion protein by introducing a sequence of a single chain variable fragment (scFv) into ferritin, and using the fusion protein, 24 antigen recognition sites of the antibody are expressed on the ferritin surface of the antibody, System, disease diagnosis and therapeutic drug development.

Description

Fusion proteins comprising single chain antibody fragments and ferritin, and uses thereof and novel fragments thereof,

The present invention relates to a fusion protein comprising a single chain antibody fragment and ferritin and a use thereof. More particularly, the present invention relates to a fusion protein in which a single chain antibody fragment (scFv) and ferritin are bound, A polynucleotide, an expression vector comprising the polynucleotide, a transformant into which the expression vector is introduced, a method of culturing the transformant and producing the fusion protein from the polynucleotide, a nanocluster comprising the fusion protein, A diagnostic kit, a protein chip, and an antigen detection method using the nanoclusters.

Ferritin is a protein that stores iron and is widely found in prokaryotes and eukaryotes. The molecular weight of ferritin is about 500.000 Da, consisting of a heavy chain and a light chain. It has self-assembly ability and shows unique characteristics of forming spherical particles. Ferritin is a protein in which 24 monomers (a single monomer or a single monomer composed of one heavy chain or light chain) are assembled to form a huge spherical tertiary structure. In the case of human ferritin, the outer diameter is about 12 nm and the inner diameter is about 8 nm . Ferritin may be dispersed into monomers according to pH conditions and may form nanoclustes with 24 monomers combined. These characteristics can capture various substances in ferritin. In general, nano-cluster ferritin has iron oxide in its interior. In addition, ferric nitrides have a variety of inorganic metals such as manganese oxide, cobalt oxide, nickel oxide, indium oxide, iron sulfide, cadmium sulfide, selenocadmium, Examples of ferritin production have been reported. In addition, a case has been reported in which ferritin is captured by using a peptide selectively binding to a metal, for example, using a peptide that binds to silver. In particular, ferritin, which captures Gd-HPDOTA (gadolinium- [10- (2-hydroxypropyl) -1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid), which is an MRI contrast agent, has also been reported. In this way, various functional groups can be introduced through the molecular biology of the interior and exterior of ferritin. The ferritin structure incorporating various functional groups can be modified by an appropriate functional group using various functional groups, It has an advantage that it can impart properties. For example, introducing a peptide sequence that selectively binds to a specific metal at an appropriate position in the ferritin allows the metal ion to selectively bind and carry with the protein. In this process, even when a single formula is introduced into the ferritin protein monomer, self-assembly of the protein nanoclusters composed of 24 complexes results in 24 homogeneous formulas. As a result, one ferritin nanocluster is formed in a very elaborate form It can serve as a transporting body for transporting the metal ions.

On the other hand, a target-oriented drug delivery system refers to a technology designed to selectively deliver a drug to a treatment site so that healthy tissue is not exposed to the drug, and at the same time, an excellent therapeutic effect can be obtained even with a small amount of drug. Using a targeted drug delivery system can maximize the effectiveness of drug treatment by concentrating the drug on a specific area of a diseased human body, and it can minimize side effects caused by toxic drugs such as anticancer drugs. In addition, in recent years, attempts have been made to utilize a target-oriented drug delivery system for disease diagnosis. More recently, the development of Theragnosis (Therapy + Therapy) technology, which can simultaneously perform treatment and diagnosis using a target-oriented drug delivery system, is actively under way. That is, by attaching a molecular imaging probe to a target-oriented drug delivery system and imaging the tracer using non-invasive in vivo imaging, The technology that can be done is TerraGinosis technology.

Representative materials that impart target orientation in almost all cases are signal peptides and antibodies. Antibodies are very common, but it is known that it is very difficult to selectively modify a specific region of an antibody when using an antibody. Antibodies are proteins produced by the immune response of vertebrates. They are immune proteins that specifically recognize and bind specific sites of the antigen to inactivate or eliminate the action of the antigen. Antibodies have two heavy chains and two light chains and are basically Y-shaped. The variable region of the light chain and the heavy chain are combined to form an antigen binding site. A single fragment of a single chain variable fragment (scFv), which is artificially linked through a peptide linker, Research is being conducted to perform the functions of the present invention. Since single chain variable fragment (scFv) is smaller than general antibodies, it has a high penetration rate into tissues and cancerous tissues, can be mass-produced in various expression systems including E. coli system, and various molecular biological formulas And can save time and money in production. However, this single chain variable fragment has a short half-life in the human body because of its small size and lack of Fc region. The reported thyroid stimulating hormone (TSH) - ferritin is expressed in Escherichia coli but has a problem that precipitation is formed and not self-assembled, so that refolding process using additional strong acid is essential. This is essential for the production of functional protein nanoparticles It consumes a lot of time and money, and it can also adversely affect inherent functions (selectivity, binding ability, stability) by denaturing proteins.

Nano-structures such as liposomes are widely used as medicines. Liposomes are mainly composed of phospholipid, which is a constituent of a vital cell membrane, and can collect water-soluble or insoluble (hydrophobic) drugs therein. Liposomes have the advantage of being able to control various constituents and surface components, but they are highly toxic to cells and have problems such as phagocytosis of phagocytes when they are injected into the circulation system. As a technique for solving these problems, a stealth liposome has been developed in which a liposome is bound to PEG at the terminal of a phospholipid or a liposome surface is coated with PEG or a polysaccharide. Another nanostructure, micelle, is a carrier composed of a chain-like molecule having both hydrophilic and hydrophobic sites. In the aqueous phase, the hydrophobic parts are gathered together to form a spherical shape at the central part. Usually, the poorly soluble drug is collected at the center to increase the solubility, . In the case of anticancer drugs, nanoparticle drug delivery systems selectively accumulate in cancer tissues through the enhanced permeability and retention (EPR) effect, which is a passive targeting method. In general, cancer tissue is supplied with nutrients and oxygen through the new blood vessels. Since blood vessels are formed within a short period of time, unlike normal cells, they have a loose structure. Through the loose vascular tissue formed in cancer tissue, nanoparticles of several tens to several hundreds of nanometers can accumulate around the cancer tissues and have a slow release rate and stay in cancer tissues for a long time. This phenomenon is called enhanced permeability and retention do. However, this effect is a passive method using the environment around the cancer, so it is difficult to expect a certain effect at all times. Therefore, in order to achieve more effective targeting, a method using a drug delivery system having an antibody capable of recognizing an antigen or a receptor expressed at a target site has been developed. In addition, combining a selective antibody with a variety of contrast media for chemotherapy and radiotherapy for chemotherapy can reduce systemic side effects, increase the effectiveness of the treatment, and improve the accuracy of the image. Currently, the chemical covalent bond forming method used as an immobilization method for an antibody for targeting is poor in reproducibility and may impair the inherent function of the antibody. In the case of biologically derived medicines as well as general medicines, structural changes in the manufacturing process must be accompanied by a clear identification of structural changes, drug efficacy and toxicity testing in order to obtain approval from the KFDA. Therefore, it is almost impossible to apply a target-oriented drug delivery system using antibodies to human body without ensuring reproducibility of antibody immobilization.

Under these circumstances, the inventors of the present invention have made extensive efforts to develop a method for improving the utilization of a single-chain antibody fragment (scFv). As a result, it has been found that a fusion protein in which scFv and ferritin are bound, And that the formed nanocluster exhibits an effect of enhancing the activity of scFv. Thus, the present invention has been completed.

One object of the present invention is to provide fusion proteins in the form of single chain antibody fragments (scFv) and ferritin bound.

Another object of the present invention is to provide a polynucleotide encoding said fusion protein.

It is still another object of the present invention to provide an expression vector comprising the polynucleotide.

It is still another object of the present invention to provide a transformant into which the above expression vector has been introduced.

It is still another object of the present invention to provide a method for culturing the transformant and preparing the fusion protein therefrom.

Yet another object of the present invention is to provide a nanocluster comprising said fusion protein.

It is still another object of the present invention to provide a drug carrier comprising the nanoclusters.

Yet another object of the present invention is to provide a diagnostic kit comprising the nanoclusters.

It is still another object of the present invention to provide a protein chip comprising the nanoclusters.

It is still another object of the present invention to provide an antigen detection method using the nanoclusters.

The present inventors have conducted various studies to develop a method for improving the utility of single-chain antibody fragments (scFv), and have focused on ferritin capable of forming nanoclusters by self-binding. The present inventors have developed nanoparticles containing 24 monomers composed of an antibody-binding peptide-ferritin fusion protein and a technique for improving the usability of the antibody by binding various antibodies thereto (Korean Patent No. 1477123 number). The present inventors have found that complexes in which scFv is bound to the ferritin can form nanoclusters of the same type by self-binding activity derived from ferritin without interfering with the fused scFv. The nanoclusters thus formed exhibit densified forms of 24 scFvs, and thus exhibit better antibody activity than conventional scFvs, and their usability can be improved. In order to verify this, each of scFvs derived from known Avastin as a monoclonal antibody against Herceptin or VEGF, which is known as a monoclonal antibody against HER2, was prepared, and a fusion protein in which the scFv and ferritin were combined was obtained. And activity. As a result, the fusion protein formed nanoclusters in the form of a combination of 24 monomers due to self-assembly activity, and the scFv bound to the nanoclusters exhibited a relatively low level of binding to the monoclonal antibody (Herceptin or Avastin) Activity, but showed relatively high level of binding activity than scFv.

Accordingly, the fusion protein of the scFv and ferritin-linked forms provided in the present invention has a remarkably small size than the conventional antibody, and while showing the characteristics of the scFv that is easy to produce and manipulate, it is a disadvantage of the conventional scFv Lt; RTI ID = 0.0 > scFv < / RTI > since it improves the low binding activity to the indicated antigen. Such a fusion protein in which scFv and ferritin are combined is not known at all and has been developed for the first time by the present inventors.

In order to achieve the above object, the present invention provides, as one embodiment, a fusion protein in which a single chain antibody fragment (scFv) and ferritin are bound.

The term "single chain variable fragment (scFv)" as used herein refers to not a general fragment formed from an antibody but a fragment comprising a variable region of a heavy chain constituting an antibody and a fragment containing a variable region of a light chain It is a fusion protein composed by artificially fusing. The scFv may be a form in which a heavy chain fragment and a light chain fragment derived from various antibodies such as a monoclonal antibody and a polyclonal antibody are sequentially or in a reverse sequence, and between the heavy chain fragment and the light chain fragment, 10 to 25 amino acid sequences The constructed peptide linker may be inserted. At this time, the linker used may be a peptide linker composed of serine (S) and glycine (G). The length of the linker is not particularly limited, and SG, SGGGGSGGGG, SGGGGSGGGGSGGGG, SGGGGSGGGGSGGGGSGGGG and the like are used in the present invention.

In the present invention, the kind of the scFv is not limited, and any kind of scFv can be introduced when the amino acid and the nucleic acid sequence are known.

In this case, the antibody that is the source of the scFv binding to the nanoclusters according to the present invention may be a therapeutic antibody, an antibody capable of binding with a separate therapeutic agent or a diagnostic agent, Or may simply be an antibody capable of an antigen-antibody reaction. The therapeutic or diagnostic agent may bind to the antibody, but may also be carried by the nanoclusters according to the present invention.

Meanwhile, about 30 therapeutic antibodies have been approved by the FDA and their safety is very high because they closely resemble those of in vivo IgG. Therapeutic antibodies are used in a wide range of disease treatments (eg, transplant rejection, cancer, autoimmune diseases and inflammation, heart disease, infectious infection, etc.) and these antibodies are specific for receptor proteins or antigenic proteins And thus the specificity is very high. Therefore, combining a molecular imaging probe or a drug delivery vehicle with a therapeutic antibody can turn the therapeutic agent into a teraginous agent capable of monitoring the therapeutic process as well as the effect of the drug combination. In addition, by combining a molecular imaging probe or a drug delivery system with a simple targeting antibody, it is possible to develop a teraginosis preparation for diagnosis, treatment, or simultaneous diagnosis and treatment. The present invention relates to a method for preparing a target-oriented teraginosaceous material by introducing a molecular image probe, a therapeutic drug, etc. into a nanocluster by fusing a single chain variable fragment (scFv) to biologically-derived ferritin Can be provided.

In addition, the scFv may comprise a peptide linker consisting of 2 to 20 peptides between a heavy chain fragment and a light chain fragment derived from a monoclonal antibody. In this case, the peptide linker used may be, for example, a peptide linker composed of serine (S) and glycine (G), but not limited thereto. In the present invention, SG, SGGGGSGGGG, SGGGGSGGGGSGGGG, SGGGGSGGGGSGGGGSGGGG and the like were used.

Usually, "ferritin" is a type of protein capable of binding iron ions, has a molecular weight of about 500 kDa, is composed of a heavy chain and a light chain, And exhibit unique characteristics of forming spherical particles. The ferritin can form a gigantic spherical tertiary structure by combining 24 monomers (a single monomer or a heterogeneous monomer composed of one heavy chain or light chain). For example, in the case of human ferritin, the outer diameter is about 12 nm, Is about 8 nm. In addition, ferritin may be dispersed into monomers depending on pH conditions and may form nanoclusters in which 24 monomers are combined. Using these properties, ferritin can capture various substances in the ferritin, and the nanocluster-like ferritin has iron oxide, but may also include various inorganic metals such as manganese oxide, cobalt oxide, nickel oxide, indium oxide, iron sulfide, cadmium sulfide, selenocadmium, and selenoacene. The specific base sequence and protein information of the gene encoding the protein is known from NCBI (GenBank: NM_000146, NM_002032, etc.). For example, in the present invention, a protein expressed from a polynucleotide consisting of a nucleotide sequence of SEQ ID NO: 1 derived from a human is used as ferritin.

In the present invention, the ferritin has a partial structure capable of having a high local concentration or a multi-valency effect when the 24 ferritin monomers form nanoclusters, and each of the protein monomers (Amino acid sequence) (see Fig. 2). Therefore, when the protein moiety forming the symmetry point is modified, three to four matrices are encountered at the same site. The present inventors introduced scFv to the N-terminal or C-terminal of the ferritin protein so that the scFv is located at the same point on the surface of the ferritin nanocluster , And various kinds of scFvs can be inserted into the platform DNA. By introducing scFv derived from Herceptin, a breast cancer therapeutic agent or Avastin, an angiogenesis inhibitor, as a therapeutic antibody, a ferritin nanocluster structure having a new function was developed and confirmed its function, And can be converted into various ScFv nanoclusters.

Meanwhile, the ferritin may be all derived from the same source as long as 24 monomers can form nanoclusters while maintaining the self-binding activity even in the state where scFv is bound, and the ferritin may be a mixture of heterogeneous ferritins You may. Ferritin may be microorganism-derived ferritin, such as bacteria, or eukaryotic cell-derived ferritin. Preferably human-derived ferritin.

In addition, the ferritin may be a mutein in which at least one amino acid residue in the native amino acid sequence is substituted with cysteine or further inserted with cysteine. Cysteine itself has a high affinity for heavy metals, and further includes a thiol group having high reactivity, so that it can be easily coupled with other reactors, thereby facilitating the introduction of a drug directly or through a linker. Preferably, the cysteine is selected from the group consisting of a second Ser (serine), a 19th Ser (serine), a 61st Glu (glutamic acid), a 68th Lys (lysine), a 102nd Ala or an amino acid residue containing at least one of cysteine or cysteine at the 1st and 2nd, 161st, 162nd or 174th positions of the amino acid sequence of Pyrococcus furiosus, More than one sequence may be inserted. The inserted sequence may be a single cysteine residue or a GGC sequence, but may be used without restriction if it contains one or more cysteines and does not alter the structure of the native protein. Substitution or insertion into the cysteine may be performed using any method known to those skilled in the art without limitation, but preferably by site-directed mutagenesis.

For example, it is possible to replace the second Ser (serine), 19th Ser (serine), 102th Ala (alanine) or 113th Asp (aspartic acid) of the human-derived ferritin amino acid sequence with one or more cysteines, or with an amino acid of Pyrococcus furiosus One or more additional amino acids between the first and second amino acids of the sequence to form nanoparticles comprising cysteine capable of binding to a drug exposed to the external surface. It is also possible to replace the 61st Glu (glutamic acid), the 68th Lys (lysine) or the 137th Glu (glutamic acid) of the human-derived ferritin amino acid sequence with one or more cysteines or the 161st and 162nd amino acids of the amino acid sequence of Pyrococcus furiosus At least one amino acid sequence including cysteine or cysteine may be further inserted after 174th to prepare nanoparticles containing cysteine capable of binding to the drug exposed on the inner surface.

In addition, the ferritin may further comprise an amino acid sequence designed for a specific purpose to increase the stability of the targeting sequence, tag, labeled residue, half-life or peptide, and some amino acids of the known amino acid sequence may be added, Substitution, deletion, etc., mutant protein variants can also be included in the category of ferritin provided in the present invention.

In particular, the ferritin provided in the present invention may include a polypeptide having a sequence that differs from a known amino acid sequence by one or more amino acid residues. Amino acid exchange in proteins and polypeptides that do not globally alter the activity of the molecule is known in the art. The most commonly occurring exchanges involve amino acid residues Ala / Ser, Val / Ile, Asp / Glu, Thr / Ser, Ala / Gly, Ala / Thr, Ser / Asn, Ala / Val, Ser / Gly, Thy / Pro, Lys / Arg, Asp / Asn, Leu / Ile, Leu / Val, Ala / Glu and Asp / Gly. In addition, the protein may include a protein having increased structural stability or increased protein activity due to mutation or modification of the amino acid sequence, such as heat, pH and the like.

In general, a "fusion protein" is known as a protein in which two or more different proteins are combined. In the present invention, the fusion protein is limited to a fusion protein in which scFv is bound to ferritin. , And the scFv may be a fusion protein in which the N-terminal or the C-terminal of the ferritin is bound. The fusion protein may be in the form that the scFv derived from various antibodies is indirectly bound to the ferritin either directly or through a linker. The length and / or amino acid composition of the linker may be controlled to control the spacing and orientation of the scFvs.

The fusion protein can form spherical nanoclusters by 24 self-assembly, and the diameter of the nanoclusters may be 10 to 30 nm. When the fusion protein is used, it is possible to induce nanocluster formation having strong antigen binding force through self-assembly only by protein expression and purification.

According to one embodiment of the present invention, a fusion protein in which an scFv is fused to the N-terminal or C-terminal of ferritin may contain 3 to 4 scFvs in a specific region of ferritin, The nanoclusters that are capable of binding to one or more antigens can be bound to three or four scFvs bound to a specific site of ferritin.

According to one embodiment of the present invention, a ferritin platform vector for preparing a single chain variable fragment (scFv) -ferritin fusion protein was prepared (Example 1) The resulting scFv-ferritin fusion protein was analyzed and its characteristics were analyzed. As a result, it was confirmed that the purified scFv-ferritin fusion protein formed a collective structure in which 24 monomers were assembled to form a globule as a whole (FIG. 8) Ferritin fusion protein showed a relatively higher level of affinity for the HER2 antigen than the Herceptin and Herceptin-derived scFv, and the scFv-ferritin fusion protein showed a higher level of binding to HER2 than Herceptin But relatively high level than that of Herceptin-derived scFv (Fig. 9 Table 1). Meanwhile, the avantin-derived scFv-ferritin fusion protein was prepared using the prepared platform vector, and the characteristics thereof were analyzed. As a result, similar to the Herceptin-derived scFv-ferritin fusion protein, the affinity for VEGF, The ferritin fusion protein showed a relatively higher level than the avastin and avastin derived scFv, and the scFv-ferritin fusion protein showed a relatively lower level than the avastin in terms of the binding ability to VEGF, but the relative level was higher than that of the avastin-derived scFv (Fig. 11 and Table 4).

In addition, it is possible to form a protein complex in which a metal ion is bound to a nanocluster prepared using a mutant obtained by introducing cysteine into the scFv-ferritin fusion protein (Example 4) Or can be used for treatment.

According to another aspect of the present invention, there is provided a polynucleotide comprising a nucleotide sequence encoding the fusion protein.

In the present invention, the nucleotide sequence constituting the polynucleotide may be a nucleotide sequence capable of encoding the amino acid sequence of the fusion protein or a nucleotide sequence encoding a variety of amino acid sequences that can be added to the N-terminal or C-terminal of the amino acid sequence The base sequence may be added to the 5'-terminal or 3'-terminal of the base sequence capable of encoding the amino acid sequence.

In addition, as long as it is capable of encoding a protein capable of forming a nanocluster in the same manner as conventional ferritin, a polynucleotide comprising a nucleotide sequence having homology with the above nucleotide sequence is also included in the category of the polynucleotide provided in the present invention . The polynucleotide may be a polynucleotide including a nucleotide sequence preferably showing a homology of 80% or more, more preferably a polynucleotide including a nucleotide sequence having 90% or more homology, The polynucleotide may be a polynucleotide comprising a nucleotide sequence having 95% or more homology.

On the other hand, the polynucleotide may be mutated by substitution, deletion, insertion, or a combination of one or more bases. When the nucleotide sequence is prepared by chemically synthesizing, it is possible to use a method well known in the art, for example, a method described in Engels and Uhlmann, Angew Chem IntEd Engl., 37: 73-127, 1988 , Triesters, phosphites, phosphoramidites and H-phosphate methods, PCR and other auto primer methods, and oligonucleotide synthesis on solid supports.

In another aspect, the present invention provides an expression vector comprising the polynucleotide.

In the present invention, an "expression vector" may be a gene construct comprising a gene insert that is capable of expressing a target protein in an appropriate host cell, and an essential regulatory element operably linked to express the gene insert. The expression vector includes expression control elements such as an initiation codon, a termination codon, a promoter, an operator, etc. The initiation codon and termination codon are generally regarded as part of the nucleotide sequence encoding the polypeptide, and when the gene product is administered, And may be provided in a coding sequence and an in-frame. The promoter of the vector may be constitutive or inducible.

Typically, the expression vector is capable of autonomous replication in a host, and can be composed of a promoter, a ribosome binding sequence, a nucleic acid of the present invention, and a transcription termination sequence. Any promoter may be used as long as the promoter allows the nucleic acid of the present invention to be expressed in a host such as Escherichia coli. For example, Escherichia coli or phage-derived promoters such as trp promoter, lac promoter, PL promoter or PR promoter; Escherichia coli-infected phage-derived promoters such as the T7 promoter may be used. Artificially modified promoters such as the tac promoter may also be used.

The term "operably linked" of the present invention means a state in which a nucleic acid sequence encoding a desired protein or RNA is functionally linked to a nucleic acid expression control sequence so as to perform a general function . For example, a nucleic acid sequence encoding a promoter and a protein or RNA may be operably linked to affect the expression of the coding sequence. The operative linkage with an expression vector can be produced using gene recombination techniques well known in the art, and site-specific DNA cleavage and linkage can be performed using enzymes generally known in the art.

In addition, the expression vector may include a signal sequence for the release of the fusion protein to facilitate separation of the protein from the cell culture fluid. A specific initiation signal may also be required for efficient translation of the inserted nucleic acid sequence. These signals include the ATG start codon and adjacent sequences. In some cases, an exogenous translational control signal, which may include the ATG start codon, should be provided. These exogenous translational control signals and initiation codons can be of various natural and synthetic sources. Expression efficiency can be increased by the introduction of suitable transcription or translation enhancers.

In addition, the expression vector may further comprise a protein tag that can be optionally removed using endopeptidase to facilitate detection of the fusion protein.

The term "tag " of the present invention means a molecule exhibiting quantifiable activity or property and includes a polypeptide fluorescent substance such as a fluorophore such as fluorescein, a fluorescent protein (GFP) Or may be a fluorescent molecule including; Myc tag, a Flag tag, a histidine tag, a Lucin tag, an IgG tag, or a strap tagidine tag. Particularly, in the case of using an epitope tag, a peptide tag composed of preferably 6 or more amino acid residues, more preferably 8 to 50 amino acid residues can be used.

In the present invention, the expression vector is not particularly limited as long as it is capable of producing the fusion protein provided by the present invention by expressing the polynucleotide. Examples of the expression vector include mammalian cells (e.g., human, monkey, rabbit, rat, hamster, The vector may be a vector capable of replicating and / or expressing the polynucleotide in a eukaryotic or prokaryotic cell comprising a plant cell, a yeast cell, an insect cell or a bacterial cell (for example, Escherichia coli, etc.) (PUC18, pBAD, < RTI ID = 0.0 > pUC18, < / RTI > pIDTSAMRT-AMP, etc.), E. coli-derived plasmids (pYG601BR322, pBR325, pUC118 and pUC119), Bacillus subtilis derived plasmids (pUB110 and pTP5), yeast-derived plasmids (YEp13, YEp24 and YCp50), lambda-phages (Charon4A, Charon21A, EMBL3, EMBL4, lambda gt10, lambda gt11 and lambda ZAP), retrovirus, adeno Adenovirus, vaccinia virus, baculovirus, and the like. Since the amount of expression of the protein and the expression of the expression vector are different depending on the host cell, it is preferable to select and use the host cell most suitable for the purpose.

According to another aspect of the present invention, there is provided a transformant wherein the expression vector is introduced into a host cell.

The transformant provided in the present invention can be produced by introducing the expression vector provided in the present invention into a host cell and transforming it, and expressing the polynucleotide contained in the expression vector to produce the fusion protein of the present invention .

The host cell into which the expression vector provided in the present invention can be introduced is not particularly limited as long as it is capable of producing the peptide by expressing the polynucleotide. However, the host cell may be any of E. coli, Streptomyces, Salmonella typhimurium Bacterial cells such as; Yeast cells such as Saccharomyces cerevisiae, and ski-inspected caromyces pombe; Fungal cells such as Pichia pastoris; Insect cells such as Drosophila and Spodoptera Sf9 cells; Animal cells such as CHO, COS, NSO, 293, Bowmanella cells; Or plant cells.

The transformation can be carried out by various methods. As long as it is capable of producing the fusion protein of the present invention, which exhibits an effect of improving various cell activities to a high level, the transformation can be carried out by the CaCl 2 precipitation method, The Hanahan method, the electroporation method, the calcium phosphate precipitation method, the protoplast fusion method, the agitation method using the silicon carbide fiber, the Agrobacterium-mediated transformation method, and the Agrobacterium-mediated transformation method using the reducing agent called DMSO (dimethyl sulfoxide) A transformation method using PEG, a dextran sulfate, a lipofectamine, and a dry / suppression-mediated transformation method.

As another embodiment for accomplishing the above object, the present invention provides a method for producing the fusion protein of the present invention using the above transformant.

Specifically, the method for producing the fusion protein of the present invention comprises the steps of: (a) culturing the transformant to obtain a culture; And (b) recovering the fusion protein of the present invention from the culture.

As another method, a method for producing a fusion protein of the present invention includes the steps of (a) cloning a polynucleotide encoding a fusion protein of the present invention to obtain an expression vector; (b) introducing the obtained expression vector into a host cell to obtain a transformant; And (c) culturing the transformant, and recovering the fusion protein from the transformant.

The term "cultivation" of the present invention means a method of growing the microorganism under an appropriately artificially controlled environmental condition. In the present invention, the method for culturing the transformant may be carried out by a method well known in the art. Specifically, the culture can be continuously cultured in a batch process or an injection batch or a repeated fed batch process, as long as it can produce the fusion protein of the present invention. .

The medium used for culturing can meet the requirements of a specific strain in an appropriate manner while controlling the temperature, pH and the like under aerobic conditions in a conventional medium containing an appropriate carbon source, nitrogen source, amino acid, vitamin, and the like. The carbon sources that can be used include glucose and xylose mixed sugar as main carbon sources, and sugar and carbohydrates such as sucrose, lactose, fructose, maltose, starch and cellulose, soybean oil, sunflower oil, castor oil, Oils and fats such as oils and the like, fatty acids such as palmitic acid, stearic acid, linoleic acid, alcohols such as glycerol, ethanol, and organic acids such as acetic acid. These materials may be used individually or as a mixture. Nitrogen sources that may be used include inorganic sources such as ammonia, ammonium sulfate, ammonium chloride, ammonium acetate, ammonium phosphate, ammonium carbonate, and ammonium nitrate; Amino acids such as glutamic acid, methionine and glutamine, and organic substances such as peptone, NZ-amine, meat extract, yeast extract, malt extract, corn steep liquor, casein hydrolyzate, fish or their decomposition products, defatted soybean cake or decomposition products thereof . These nitrogen sources may be used alone or in combination. The medium may include potassium phosphate, potassium phosphate and the corresponding sodium-containing salts as a source. Potassium which may be used include potassium dihydrogen phosphate or dipotassium hydrogen phosphate or the corresponding sodium-containing salts. As the inorganic compound, sodium chloride, calcium chloride, iron chloride, magnesium sulfate, iron sulfate, manganese sulfate and calcium carbonate may be used. Finally, in addition to these materials, essential growth materials such as amino acids and vitamins can be used.

In addition, suitable precursors may be used in the culture medium. The above-mentioned raw materials can be added to the culture in the culture process in a batch manner, in an oil-feeding manner or in a continuous manner by an appropriate method, but it is not particularly limited thereto. Basic compounds such as sodium hydroxide, potassium hydroxide, ammonia, or acid compounds such as phosphoric acid or sulfuric acid can be used in a suitable manner to adjust the pH of the culture.

In addition, bubble formation can be suppressed by using a defoaming agent such as a fatty acid polyglycol ester. An oxygen or oxygen-containing gas (e.g., air) is injected into the culture to maintain aerobic conditions. The temperature of the culture is usually 27 ° C to 37 ° C, preferably 30 ° C to 35 ° C. The culture is continued until the amount of the fusion protein is maximally obtained. Usually for 10 to 100 hours for this purpose.

In addition, the step of recovering the fusion protein from the culture can be carried out by a method known in the art. Specifically, the recovering method is not particularly limited as long as the recovered fusion protein of the present invention can be recovered. Preferably, the recovering method includes centrifugation, filtration, extraction, spraying, drying, evaporation, precipitation, crystallization, electrophoresis, Methods such as fractional dissolution (for example, ammonium sulfate precipitation), chromatography (for example, ion exchange, affinity, hydrophobicity and size exclusion) can be used.

In another embodiment for achieving the above object, the present invention provides a nanocluster comprising the fusion protein.

The term "nano cluster" of the present invention means a protein complex formed by self-assembly of 24 fusion proteins by the self-assembly activity of ferritin contained in the fusion protein provided in the present invention. But it may have a diameter of 10 to 30 nm, and the shape of the nanoclusters may be spherical. It is possible to form a protein chip or a target-oriented drug delivery system easily containing the scFv without damaging the structure of the scFv by inducing the formation of nanoclusters having strong binding force through self-assembly only by the expression and purification of the fusion protein have. In this case, the fusion proteins constituting the nanocluster may contain different or identical scFvs, and the ferritin contained therein may be different from or identical to each other. For example, the nanocluster may be scFv And a scFv that is bound to the drug.

In another aspect of the present invention, the present invention provides a drug carrier comprising the nanoclusters and the drug.

The nanocluster can be used as a drug delivery vehicle because scFv located on its surface or ferritin located inside thereof can be used to bind the desired drug and deliver the drug in a target-oriented manner.

The drug delivery system can be delivered to a target site by binding a scFv or ferritin forming the nanocluster to a desired drug. The drug to be bound is not particularly limited, but may be a therapeutic agent, a diagnostic agent, a detection agent, or the like .

The therapeutic agent may be, for example, an antibody, an antibody fragment, a drug, a toxin, a nucleic acid hydrolase, a hormone, an immunomodulator, a chelator, a boron compound, a photoactive agent or dye, Isotopes, and the like; Diagnostic agents or detection agents are also not particularly limited but include, for example, radioisotopes, dyes (e.g., biotin-streptavidin complexes), contrast agents, fluorescent compounds or molecules and magnetic resonance imaging MRI) (paramagnetic ion), and the like. As another example, the diagnostic agent may include a radioactive isotope, an enhancer used in magnetic resonance imaging, and a fluorescent compound.

In some cases, it may be necessary to react with a reactant having a long tail attached to a large number of chelating groups in order to bind the ions, in order to load the antibody component with radioactive metal or paramagnetic ions. The tail may be a polymer such as polylysine or polacacaride or a polymer such as ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), porphyrin, polyamine, crown ether, bis-thiosemic A chain having a pentene group that can be bonded to a chelating group such as thiosemicarbazone, polyoximes, and a group known to be useful for the above purpose. The chelate is bound to the antibody using standard chemistry. The chelate can normally be conjugated to the antibody by a minimal loss of immunoreactivity and by a group capable of forming a bond to the molecule with minimal assembly and / or internal cross-linking.

Particularly useful metal-chelate combinations include diagnostic isotopes and 2-benzyl-DTPA and monomethyl and cyclohexyl analogues thereof used in the general energy range of 60 to 4,000 keV, for example, radioisotopes include ¹²⁵ I , ¹³¹ I, ¹²³ I, ¹²⁴ I, ⁶² Cu, ⁶⁴ Cu, ¹⁸ F, ¹¹¹ In, ⁶⁷ Ga, ⁹⁹ mTc, ⁹⁴ mTc, ¹¹ C, ¹³ N, ¹⁵ O, ⁷⁶ Br, When complexed with non-radioactive metals such as iron and gadolinium, the same chelate can be usefully used for MRI when used with nanoclusters or antibodies of the present invention. Macrocyclic chelates such as NOTA, DOTA, and TETA are used with a variety of metals and radioactive metals, preferably with radionuclides of gallium, yttrium and copper, respectively. The metal-chelate complex can be made very stable by aligning the ring size with the metal of the object.

Immunoconjugates are conjugates of therapeutic or diagnostic agents and antibody components. The diagnostic agent may comprise a radioactive or non-radioactive label, a contrast agent (magnetic resonance imaging, computed tomography, or a contrast agent suitable for ultrasound), and the radioactive label may be gamma-, beta-, alpha-, It may be a positron emission isotope.

An immunomodulator is a therapeutic agent as defined herein and is typically an immune response cascade, such as macrophage, B-cell, and / or T-cell, that is proliferating or activating in the immune response cascade The cells may be stimulated, for example, the immunomodulator may be a cytokine.

In another aspect of the present invention, the present invention provides a diagnostic kit or protein chip comprising the nanoclusters.

The diagnostic kit of the present invention may comprise a nanocluster comprising an scFv capable of binding a target protein capable of diagnosing a desired disease. In this case, the target disease is not particularly limited as long as it contains a target protein that can be detected by scFv contained in the nanoclust. For example, infectious diseases caused by bacteria or viruses, genetic mutations, A metabolic disease that can be caused by influx of substances that disturb the metabolism in vivo.

The diagnostic kit may include various components necessary for detecting a target protein using the nanoclusters in addition to the nanoclusters. For example, a test tube or other suitable container, a reaction buffer, a secondary antibody, a detection agent, sterile water, an enzyme, and the like.

As an example of the diagnostic kit, a protein chip may be used. The protein chip may be a fusion protein provided by the present invention or a nanocluster composed of the fusion protein immobilized on a solid substrate. In this case, the solid substrate may be used in a biochip, Such as gold, glass, deformed silicon, tetrafluoroethylene, polystyrene, and polypropylene, and the like. Further, the surface of the substrate may be surface-treated with a polymer, plastic, resin, carbohydrate, silica, silica inducer, carbon, metal, inorganic glass and film. The substrate not only serves as a support but also provides a place where a binding reaction between the immobilized antibody and the antigen takes place. The size of the substrate and the position, size, and shape fixed on the substrate can be changed according to the purpose of the analysis, a spotting machine, a scanner, and the like.

As another example of the diagnostic kit, an ELISA kit containing the nanoclusters, a sandwich ELISA kit, and a sandwich fluorescent immunochromatographic test kit (FICT) kit in the form of a strip may be used.

For example, there is a sample injection unit capable of injecting a sample by bonding a glass fiber, cotton or cellulose pad to a nitrocellulose membrane in the form of a strip, Or a fluorescent immunochromatographic test kit (FICT).

As another embodiment for achieving the above object, the present invention provides an antigen detection method using the nanoclusters.

Specifically, the method for detecting an antigen of the present invention includes the step of adding a protein sample to the nanocluster to confirm whether an antigen-antibody reaction occurs. At this time, the nanoclusters may be freely present in the solution as in a conventional immunoprecipitation method, or may be fixed to a solid substrate, such as a conventional protein chip. In this case, the protein sample is not particularly limited, but may be used in a state in which no treatment is carried out or in a diluted state with an appropriate buffer solution, and a sample derived from a natural world to be tested for the presence or absence of an antigen The protein sample may be, for example, blood, serum, plasma, body fluid, saliva, urine, intestinal fluid, lymph fluid, peritoneal fluid, etc. separated from a patient suspected of causing the disease, and as another example , Soil samples, fresh water samples, and seawater samples. In this case, the disease is not particularly limited as long as it includes a target protein that can be detected by scFv contained in the nanoclust. For example, a specific protein is expressed due to an infectious disease or genetic mutation caused by a bacterium or a virus A metabolic disease that may be caused by influx of a substance that disturb the metabolism in vivo, and the like.

Meanwhile, the antigen contained in the protein sample is not particularly limited, but any bioactive materials that can be detected by an immunoassay method are not particularly limited. For example, an autoantibody, a ligand, a natural extract, Peptides, proteins, metal ions, synthetic drugs, natural drugs, metabolites, dielectrics, viruses and viruses, and bacteria and viruses.

In addition, in the above method, after reacting the protein sample with the nanocluster, before the occurrence of the antigen-antibody reaction is confirmed, the target substance that is not bound to the nanocluster and other substances in the sample that can not bind to the nanocluster are washed And a step of removing the magnetic field.

The present invention relates to a method for producing a fusion protein by introducing a sequence of a single chain variable fragment (scFv) into ferritin, and using the fusion protein, 24 antigen recognition sites of the antibody are expressed on the ferritin surface of the antibody, System, disease diagnosis and therapeutic drug development.

FIG. 1 is a schematic view showing a manufacturing process of a nanocluster provided in the present invention.
2 is a schematic view showing a monomer structure of a human-derived ferrite chain and a nanocluster structure formed by self-assembly.
3 is a schematic diagram showing the morphology of nanoclusters formed by self-assembly of the scFv-ferritin fusion protein.
4 is a schematic diagram showing the construction of a ferritin platform vector for expression of an scFv-ferritin fusion protein.
5 is an electrophoresis image showing the expression of a fusion protein according to protein expression conditions of the scFv-ferritin fusion protein.
6 is an electrophoresis photograph of a sample obtained in the purification process of the scFv-ferritin fusion protein.
7 is an electrophoresis photograph of a sample obtained in the purification process of scFv protein.
8 is a transmission electron microscope (TEM) photograph showing the result of confirming the morphology of the scFv-ferritin fusion protein.
FIG. 9 is a graph and a graph showing the results of comparative analysis of the binding force between Herceptin and HER2 and the binding strength between Herceptin-derived scFv-ferritin fusion protein and HER2 using SPR.
10 is a schematic diagram showing linker length and order between heavy chain and light chain constituting scFv.
11 is a graph and a graph showing the results of comparison and measurement of the binding force between avastin and VEGF and the binding force between avastin-derived scFv-ferritin fusion protein and VEGF using SPR.

Hereinafter, the present invention will be described in more detail with reference to examples. However, these examples are for illustrative purposes only, and the scope of the present invention is not limited to these examples.

Example  1: single chain antibody fragment ( single chain variable fragment ;; scFv ) - Ferritin Fusion protein production  Vector production of ferritin platform

A ferritin platform vector for the production of single chain variable fragment (scFv) -ferritin fusion protein was prepared as follows (FIG. 4). 4 is a schematic diagram showing the construction of a ferritin platform vector for expression of an scFv-ferritin fusion protein.

First, for ferritin platform vector production, ferritin (SEQ ID NO: 1) derived from a human gene bank from a Korean human gene bank was amplified by PCR using the following primers, and the vector pET 28 (a ), And the cloned ferritin gene was confirmed by sequencing.

P1: 5'-cgcggatccggcagcagcggcagcagcatgagctcccagattcgtcagaat-3 '(SEQ ID NO: 2)

P2: 5'-ccgctcgagtcattcagctaaagcttcagctaaatg-3 '(SEQ ID NO: 3)

Next, in order to introduce a peptide (SEQ ID NO: 4) inducing a structural change according to a change in pH between 158 and 175 of the ferritin protein, the ferritin gene derived from the amplified human was used as a template and the following primers PCR was performed to obtain an amplification product. The amplification product was cloned into the vector pET28 (a) using restriction enzymes BamHI and XhoI, and a ferritin protein (SEQ ID NO: 6) inserted with a peptide sequence for inducing a structural change according to pH change through DNA sequencing The nucleotide sequence coding was confirmed.

P1: 5'-cgcggatccggcagcagcggcagcagcatgagctcccagattcgtcagaat-3 '(SEQ ID NO: 2)

P3: 5'-ccgctcgagttaaagcttcagctaaagcctccgggccacccagcctgtggaggttggt-3 '(SEQ ID NO: 5)

Example  2: Herceptin ( Herceptin ) Origin scFv - Ferritin Of the fusion protein  Manufacturing and Characterization

Example  2-1: Herceptin ( Herceptin ) Origin scFv - Ferritin Of the fusion protein  Recombination DNA  making

Single chain variable fragment (scFv) fragments were synthesized using the human-derived ferritin platform vector prepared in Example 1 and Herceptin scFv gene (SEQ ID NOS: 7 and 10) widely used as a breast cancer therapeutic agent. - recombinant DNA for the preparation of ferritin fusion proteins.

First, an amplification product was obtained by performing PCR using the following primers with the scFv (LH) gene of Herceptin as a template, and the amplified product was cloned into a ferritin platform vector using restriction enzymes NdeI and BamHI, The cloned scFv (LH) gene (SEQ ID NO: 7) was identified by sequencing.

P4: 5'-gggaattccatatgaccgtggcccaggcggccg-3 '(SEQ ID NO: 8)

P5: 5'-cgcggatccgctgccggccgcgtgctggccggcctg-3 '(SEQ ID NO: 9)

Next, PCR was carried out using the following primers with the scFv (HL) gene of Herceptin as a template, and an amplification product was obtained. The amplified product was cloned into a ferritin platform vector using restriction enzymes NdeI and BamHI, The scFv (HL) gene (SEQ ID NO: 10) was confirmed by base sequence analysis.

P6: 5'-gggaattccatatgaccgtggcc caggcggccgaagtg-3 '(SEQ ID NO: 11)

P7: 5'-cgcggatccgctgccggccgcgtgctggcc ggcctg-3 '(SEQ ID NO: 12)

In addition, PCR was carried out using primers (SEQ ID NOS: 8 and 9) as the template of the scFv (LH) gene of Herceptin to obtain an amplification product. The amplification product was amplified with the restriction enzymes NdeI and BamHI using the vector pET 28 a) and the cloned scFv (LH) gene was confirmed by sequencing.

In addition, PCR was carried out using primers (SEQ ID NOS: 11 and 12) as the template of the scFv (HL) gene of Herceptin to obtain an amplification product. The amplified product was transformed into vector pET 28 a) and the cloned scFv (HL) gene was confirmed by sequencing.

Finally, a plasmid DNA encoding a scFv-ferritin fusion protein of Herceptin or a plasmid DNA encoding a scFv of Herceptin was introduced into Escherichia coli (Rosetta DE3, Novagen), respectively, to obtain respective transformants, (IPTG) at 0, 0.1, or 1 mM, and then cultured at 18 ° C or 37 ° C for 16 hours to induce the expression of each protein. Each of the transformants was suspended in a cell lysate (50 mM Tris pH 7.5, 500 mM NaCl, 5% glycerol, 0.5% 2-mercaptoethanol), disrupted with an ultrasonic generator and centrifuged to obtain supernatant , And each cell lysate or supernatant was electrophoresed (FIG. 5).

5 is an electrophoresis image showing the expression of a fusion protein according to protein expression conditions of the scFv-ferritin fusion protein. As shown in FIG. 5, cell lysates of each transformant cultured using IPTG treatment at two concentration conditions (0.1 or 1 mM) and two culture temperatures (18 DEG C or 37 DEG C) and Herceptin Ferritin fusion protein of Herceptin could be produced at a high yield when treated with 1 mM IPTG and cultured at 18 ° C.

Example  2-2: scFv - Ferritin Of the fusion protein  Purification and characterization

The scFv-ferritin fusion protein expressed from the supernatant of the cell lysate obtained from each transformant expressing the scFv-ferritin fusion protein obtained in Example 2-1 was purified.

Specifically, activated Talon resin (1 ml, Talon resin, Clontech) was washed twice with 10 ml of column buffer (50 mM Tris pH 7.5, 500 mM NaCl, 5% glycerol, 0.05% β-mercaptoethanol) The supernatant of the obtained cell lysate was added and the mixture was slowly shaken at 4 DEG C for 1 hour to adsorb the protein on the talon resin. Subsequently, the Talon resin was washed twice with a column buffer (10 ml), 10 ml of an elution buffer (100 mM imidazole) was added, and the mixture was slowly rocked for 1 hour to obtain an eluate . The protein contained in the eluate was quantitated by Bradford assay. The purified protein was analyzed by SDS-PAGE to determine the size of the protein monomer and the purity of the purified protein (FIG. 6).

6 is an electrophoresis photograph of a sample obtained in the purification process of the scFv-ferritin fusion protein. As shown in FIG. 6, it was confirmed that the scFv-ferritin fusion protein can be purified from each transformant expressing the scFv-ferritin fusion protein using the method using the Talon resin.

The scFv protein expressed from the supernatant of the cell lysate obtained from each transformant expressing the scFv protein obtained in Example 2-1 was purified by the same method as described above (Fig. 7).

7 is an electrophoresis photograph of a sample obtained in the purification process of scFv protein. As shown in FIG. 7, it was confirmed that the scFv protein can be purified from each transformant expressing the scFv protein using the method using the Talon resin.

Meanwhile, TEM (transmission electron microscope) analysis was performed on the purified scFv-ferritin fusion protein (FIG. 8).

8 is a transmission electron microscope (TEM) photograph showing the result of confirming the morphology of the scFv-ferritin fusion protein. As shown in FIG. 8, it was confirmed that the purified scFv-ferritin fusion protein formed a collective structure in which 24 monomers gathered to form a globular form as a whole.

Example  2-3: scFv - Ferritin Of the fusion protein  Antigen binding assay

The antigen binding capacity of the Herceptin-derived scFv-ferritin fusion protein was analyzed using SPR (surface plasmon resonance) assay.

Example  2-3-1: HER2 Herceptin for scFv - Ferritin Of the fusion protein  Bond strength analysis

The binding force between Herceptin and HER2, which is a circular scFv purified in Example 2-2, and the binding force between the scFv-ferritin fusion protein and HER2 were compared using SPR (surface plasmon resonance) assay.

Specifically, a Biacore T100 analyzer (GE Healthcare, Uppsala, Sweden) was used. In the biosensor analysis, a CM5 sensor chip activated with EDC / NHS (N '- (3-dimethylaminopropyl) carbodiimide hydrochloride / N-hydroxysuccinimide) , Uppsala, Sweden) with HER2 protein (10 μg / ml in 10 mM sodium acetate, pH 5.0) at a flow rate of 10 μl / min for 5 minutes. The remaining active area on the surface of the sensor chip was deactivated by addition of 1.0 M ethanolamine (pH 8.5). Herceptin or scFv-ferritin fusion protein was diluted in buffer solution (1 X PBS, pH 7.4) at each concentration, and flowed at a flow rate of 30 / / min, and a binding sensorgram and a dissociation sensorgram were confirmed ). At this time, in order to correct the sensorgram generated by nonspecific binding with the sensor chip, the cell completely deactivated by BSA (bovine serum albumin) was used and the non-specific binding was corrected by subtracting the sensorgram of BSA from the sensorgram of HER2 . The surface of the sensor chip was regenerated by flowing regeneration buffer (20 mM NaOH).

FIG. 9 is a graph and a graph showing the results of comparative analysis of the binding force between Herceptin and HER2 and the binding strength between Herceptin-derived scFv-ferritin fusion protein and HER2 using SPR. As shown in FIG. 9, it was confirmed that scFv-ferritin fusion protein exhibited a relatively higher level than Herceptin in terms of affinity for HER2 and binding force.

Example  2-3-2: HER2 For Herceptin, scFv - Ferritin Fusion protein  Or Herceptin-derived scFv Analysis of bond strength

In order to confirm the degree of binding of the scFv-ferritin fusion protein to HER2, the same method as in Example 2-3-1 was used except that the Herceptin, scFv-ferritin fusion protein or Herceptin-derived scFv was used To analyze the binding ability of Herceptin, scFv-ferritin fusion protein or Herceptin-derived scFv to HER2 (Table 1).

The binding force of Herceptin, scFv-ferritin fusion protein or Herceptin-derived scFv to HER2 ka (1 / Ms) KD (M) Chi ² Herceptin
scFv-ferritin fusion protein
Herceptin-derived scFv 4.86E + 05
6.17E + 06
2.1523 + 4 8.42E-10
8.95E-11
3.03E-08 0.0491
0.304
1.79

As shown in Table 1, the scFv-ferritin fusion protein exhibits a higher level than the Herceptin-derived scFv as well as Herceptin in terms of the affinity for HER2 and the binding force, I could.

Example  2-3-3: scFv - Ferritin Of the fusion protein  Analysis of bond strength according to structure

To confirm whether the binding force to HER2 changes depending on the structure of the scFv-ferritin fusion protein.

For this purpose, a scFv (scFv-LH) in which a light chain fragment of Herceptin and a heavy chain fragment are linked, or a scFv (scFv-HL) in which a light chain fragment of Herceptin is linked to a light chain fragment is set, A scFv-ferritin fusion protein comprising each scFv fragment designed to include various types of linkers (SG, -2 (SGGGG) -, -3 (SGGGG) - or -4 (SGGGG) -) Were produced and purified by the methods of Examples 2-1 and 2-2. The structure of each designed scFv is shown in Table 2 and FIG. 10 is a schematic diagram showing linker length and order between heavy chain and light chain constituting scFv.

ScFv of various structures designation rescue scFv LH2
scFv LH10
scFv LH15
scFv LH20
scFv HL2
scFv HL10
scFv HL15
scFv HL20 Light chain -SG- heavy chain
Light chain-2 (SGGGG) - heavy chain
Light chain-3 (SGGGG) - heavy chain
Light chain-4 (SGGGG) - heavy chain
Heavy chain-SG-
Heavy chain-2 (SGGGG) -light chain
Heavy chain-3 (SGGGG) -light chain
Heavy chain-4 (SGGGG) -light chain

The binding activity of each of the scFv-ferritin fusion proteins to HER2 was analyzed by the same method as in Example 2-3-1, except that each of the obtained scFv-ferritin fusion proteins was used 2). At this time, Herceptin was used as a control.

Analysis of binding force according to structure of scFv-ferritin fusion protein Antibody Kinetics Fit
(1: 1 binding) Affinity Fit
(Steady state affinity) KD (M) Chi ² (RU ² ) KD (M) Chi ² (RU ² ) Herceptin
scFv LH2
scFv LH10
scFv LH15
scFv LH20
scFv HL2
scFv HL10
scFv HL15
scFv HL20 3.03E-10
3.74E-10
1.48E-09
1.86E-10
6.17E-10
3.83E-10
1.88E-10
9.59E-11
9.06E-11 0.109
0.0889
0.0516
0.401
0.0513
0.112
0.129
0.149
0.226 1.03E-08
4.91E-09
8.63E-09
1.59E-09
2.23E-09
7.87E-09
4.81E-09
3.09E-09
2.25E-09 0.114
0.0437
0.00361
0.136
0.00903
0.0281
0.0212
0.0582
0.0916

As shown in Table 3, it was confirmed that when the linker was added in constructing the scFv, the binding force of the scFv-ferritin fusion protein could be changed according to the length of the added linker. In particular, in the case of a fusion protein containing scFv HL having linkers of various lengths, the KD (M) value tended to decrease as the length of the linker increased.

Therefore, since the fusion protein including the linker-added scFv HL was analyzed to increase the binding force as the length of the linker increases, the length of the linker is an important factor for determining the antigen binding capacity of the scFv-ferritin fusion protein .

In addition, since the change in length of the linker involves a structural change of scFv, the result that the binding force increases as the length of the linker increases in the fusion protein including the linker-added scFv HL, indicates that the structural change of the scFv- Suggesting that it may directly affect the function of ferritin fusion proteins.

Example  3: Avastin ( Avastin ) Origin scFv - Ferritin Of the fusion protein  Manufacturing and Characterization

Example  3-1: scFv - Ferritin Fusion protein  Recombination for manufacturing DNA  making

First, an amplification product was obtained by performing PCR using the following primers with the scFv (LH) gene (SEQ ID NO: 13) of Avastin as a template, and the amplified product was cloned into a ferritin platform vector using restriction enzymes NdeI and BamHI And the scFv (LH) gene of cloned avastin was confirmed by sequencing.

P8: 5'-gggaattccat atggatatccagatgacacagtcc-3 '(SEQ ID NO: 14)

P9: 5'-ggtcgcggatcccgcgtgctggccggcctg-3 '(SEQ ID NO: 15)

Next, PCR was carried out using the following primers with the scFv (HL) gene (SEQ ID NO: 16) of Avastin as a template, and an amplification product was obtained. The amplified products were amplified by restriction enzymes NdeI and BamHI to a ferritin platform vector The scFv (HL) gene of cloned and cloned avastin was confirmed by sequencing.

P10: 5'-gggaattccatatggaagtccagttggtggagtcc-3 '(SEQ ID NO: 17)

P9: 5'-ggtcgcggatcccgcgtgctggccggcctg-3 '(SEQ ID NO: 15)

PCR was performed using the following primers with the scFv (LH) gene (SEQ ID NO: 13) of Avastin as a template, and an amplification product was obtained. The amplified product was digested with pET 28 (a) using restriction enzymes NdeI and BamHI, Cloned into the vector, and the scFv (LH) gene of the cloned avastin was confirmed by sequencing.

P8: 5'-gggaattccat atggatatccagatgacacagtcc-3 '(SEQ ID NO: 14)

P11: 5'-ggtcgcggatcc ttacgcgtgctggccggcctg-3 '(SEQ ID NO: 18)

In addition, PCR was performed using primers (SEQ ID NOS: 17 and 18) with the scFv (HL) gene (SEQ ID NO: 16) of Avastin as a template and amplification products were obtained. The amplified products were digested with restriction enzymes NdeI and BamHI , Cloned into the pET 28 (a) vector, and the cloned avastin scFv (HL) gene was confirmed by sequencing.

Finally, a plasmid DNA encoding an avastin scFv-ferritin fusion protein and a plasmid DNA encoding an avastin scFv were introduced into Escherichia coli (Rosetta DE3, Novagen) to obtain transformants, and the transformants were cultured , IPTG (Isopropyl-β-D-thio-galactoside) was added to 1 mM and then cultured at 18 ° C. for 16 hours to induce the expression of each protein. The avastin-derived scFv-ferritin fusion protein was purified using the method of Example 2-2 above, except that the respective transformants from which expression of each protein was induced were used.

Example  3-2: scFv - Ferritin Of the fusion protein  Antigen binding assay

Example  3-2-1: VEGF For Avastin's  Bond strength analysis

The binding force between avastin and VEGF was measured using the method of Example 2-3-1, except that the scFv circular purified avastin and the avastin-derived scFv-ferritin fusion protein purified in Example 3-1 were used. The binding force between the scFv-ferritin fusion protein and VEGF was compared (FIG. 11).

11 is a graph and a graph showing the results of comparison and measurement of the binding force between avastin and VEGF and the binding force between avastin-derived scFv-ferritin fusion protein and VEGF using SPR. As shown in FIG. 11, the scFv-ferritin fusion protein showed a relatively high level of affinity for VEGF than avastin, but the scFv-ferritin fusion protein was found to have a relatively lower level of avidity than that of avastin Respectively.

Example  3-2-2: VEGF For Avastin , scFv - Ferritin Fusion protein  or Abbas Tin Origin scFv Analysis of bond strength

To confirm the degree of binding of the scFv-ferritin fusion protein to VEGF, the same method as in Example 2-3-1 was used except that the avastin, the scFv-ferritin fusion protein or the avastin-derived scFv was used To analyze the binding ability of avastin, scFv-ferritin fusion protein or avastin-derived scFv to VEGF (Table 4).

The binding affinity of avastin, scFv-ferritin fusion protein or avastin-derived scFv to VEGF ka (1 / Ms) KD (M) Chi ² Avastin
scFv-ferritin fusion protein
Avastin-derived scFv 4.59E + 04
1.42E + 06
1.16E + 04 2.98E-11
6.83E-10
1.12E-06 0.17
0.796
1.12

As shown in Table 4, in terms of affinity for VEGF, the scFv-ferritin fusion protein showed a higher level than the avastin and avastin-derived scFv, and in view of the binding ability to VEGF, the scFv- , But it was found to be relatively higher than that of avastin-derived scFv.

Example  4: Cysteine introduced scFv - Ferritin Of the fusion protein  Produce

Example  4-1: Cysteine introduced scFv - Ferritin Of the fusion protein  making

A mutant in which a cysteine residue was introduced at a specific position of a human-derived ferritin-single chain variable fragment (scFv) fusion protein was prepared. Specifically, in order to introduce cysteine into the nanoclusters, E (Glu) at position 64 and E (Glu) at position 140 were replaced with cysteine, respectively. To introduce cysteine to the outside of the nanocluster, PCR was carried out using the following primers to substitute cysteine for A (Ala) and D (Asp) for 116, respectively, to obtain respective amplified fragments.

E64C F: 5'-gccgaggagaagcgctgcggctacgagcgtctcctg-3 '(SEQ ID NO: 19)

E64C R: 5'-caggagacgctcgtagccgcagcgcttctcctcggc-3 '(SEQ ID NO: 20)

E140C F: 5'-actcacttcctagattgcgaagtgaagcttatcaag-3 '(SEQ ID NO: 21)

E140C R: 5'-cttgataagcttcacttcgcaatctaggaagtgagt-3 '(SEQ ID NO: 22)

S22C F: 5'-gaggcagccgtcaactgcctggtcaatttgtacctg-3 '(SEQ ID NO: 23)

S22C R: 5'-caggtacaaattgaccaggcagttgacggctgcctc-3 '(SEQ ID NO: 24)

A105C F: 5'-atgaaa gctgccatgtgcctggagaaaaagctgaac-3 '(SEQ ID NO: 25)

A105C R: 5'-gttcagctttttctccaggcacatggcagctttcat-3 '(SEQ ID NO: 26)

D116C F: 5'-aaccaggcccttttgtgccttcatgccctgggttct-3 '(SEQ ID NO: 27)

D116C R: 5'-agaacccagggcatgaaggcacaaaagggcctggtt-3 '(SEQ ID NO: 28)

The obtained amplified fragment was treated with a restriction enzyme DpnI and introduced into Escherichia coli to obtain respective transformants. Then, the nucleotide sequence of the introduced DNA was confirmed from the obtained transformant to confirm that the mutation was induced Respectively. Next, the methods of Examples 2-1 and 2-2 were carried out, except that the transformant was used as a target, to prepare a scFv-ferritin fusion protein into which cysteine was introduced.

Example  4-2: The metal ligand Combined  Fabrication of nanoclusters

The nanoclusters formed using the cysteine-introduced scFv-ferritin fusion protein prepared in Example 4-1 were dissolved in an oxygen-free 50 mM pH 7.5 phosphate buffer, treated with 10 mM TCEP and reacted for 30 minutes , PD10 column chromatography to remove excess organic reagent and recover the nanoclusters. DTPA-maleimidoethylamide (DTPA-MEA) or DTPA-bromoacetamidoethylamide (DTPA-BAEA)) was added to the recovered nanoclusters per protein monomer 10 equivalents, and the reaction was carried out at room temperature for 10 hours or at 4 DEG C for 24 hours. After the reaction was completed, the reaction product was applied to PD10 column chromatography to remove excess unreacted reagent, thereby preparing a nanocluster to which a metal ion coordination ligand was bound. At this time, the binding level of the metal ion coordination ligand was confirmed by mass analysis.

Example  4-3: Metal ion Combined  Fabrication of nanoclusters

The metal ion corresponding to 1.1 equivalents of the ligand was added to the nanocluster bound to the metal ion coordination ligand prepared in Example 4-2, and used for imaging or treatment, or after purification using PD-10 desalting column.

<110> Dongguk University Industry-Academic Cooperation Foundation <120> Novel fusion protein comprising scFv and ferritin and uses          the <130> KPA150072-KR <160> 28 <170> Kopatentin 2.0 <210> 1 <211> 528 <212> DNA <213> Artificial Sequence <220> <223> recombinant ferritin DNA <400> 1 atgagctccc agattcgtca gaattattcc accgacgtgg aggcagccgt caacagcctg 60 gtcaatttgt acctgcaggc ctcctacacc tacctctctc tgggcttcta tttcgaccgc 120 gatgatgtgg ctctggaagg cgtgagccac ttcttccgcg aactggccga ggagaagcgc 180 gagggctacg agcgtctcct gaagatgcaa aaccagcgtg gcggccgcgc tctcttccag 240 gacatcaaga agccagctga agatgagtgg ggtaaaaccc cagacgccat gaaagctgcc 300 atggccctgg agaaaaagct gaaccaggcc cttttggatc ttcatgccct gggttctgcc 360 cgcacggacc cccatctctg tgacttcctg gagactcact tcctagatga ggaagtgaag 420 cttatcaaga agatgggtga ccacctgacc aacctccaca ggctgggtgg cccggaggct 480 gggctgggcg agtatctctt cgaaaggctc actctcaagc acgactaa 528 <210> 2 <211> 51 <212> DNA <213> Artificial Sequence <220> <223> primer <400> 2 cgcggatccg gcagcagcgg cagcagcatg agctcccaga ttcgtcagaa t 51 <210> 3 <211> 36 <212> DNA <213> Artificial Sequence <220> <223> primer <400> 3 ccgctcgagt cattcagcta aagcttcagc taaatg 36 <210> 4 <211> 17 <212> PRT <213> Artificial Sequence <220> <223> peptide <400> 4 Glu Ala Leu Ala Glu Ala Leu Ala Glu His Leu Ala Glu Ala Leu Ala   1 5 10 15 Glu     <210> 5 <211> 58 <212> DNA <213> Artificial Sequence <220> <223> primer <400> 5 ccgctcgagt taaagcttca gctaaagcct ccgggccacc cagcctgtgg aggttggt 58 <210> 6 <211> 195 <212> PRT <213> Artificial Sequence <220> <223> recombinant ferritin <400> 6 Met Ala Ser Met Thr Gly Gly Gln Gln Met Gly Arg Gly Ser Gly Ser   1 5 10 15 Ser Gly Ser Ser Met Ser Ser Gln Ile Arg Gln Asn His Ser Thr Asp              20 25 30 Val Glu Ala Ala Val Asn Ser Leu Val Asn Leu Tyr Leu Gln Ala Ser          35 40 45 Tyr Thr Tyr Leu Ser Leu Gly Phe Tyr Phe Asp Arg Asp Asp Val Ala      50 55 60 Leu Glu Gly Val Ser Ser Phe Phe Arg Glu Leu Ala Glu Glu Lys Arg  65 70 75 80 Glu Gly Tyr Glu Arg Leu Leu Lys Met Gln Asn Gln Arg Gly Gly Arg                  85 90 95 Ala Leu Phe Gln Asp Ile Lys Lys Pro Ala Glu Asp Glu Trp Gly Lys             100 105 110 Thr Pro Asp Ala Met Lys Ala Ala Met Ala Leu Glu Lys Lys Leu Asn         115 120 125 Gln Ala Leu Leu Asp Leu His Ala Leu Gly Ser Ala Arg Thr Asp Pro     130 135 140 Leu Leu Cys Asp Phe Leu Glu Thr His Phe Leu Asp Glu Glu Val Lys 145 150 155 160 Leu Ile Lys Lys Met Gly Asp His Leu Thr Asn Leu His Arg Leu Gly                 165 170 175 Gly Pro Glu Ala Glu Ala Glu Ala Glu Ala Glu His Leu Ala Glu Ala             180 185 190 Leu Ala Glu         195 <210> 7 <211> 810 <212> DNA <213> Artificial Sequence <220> <223> scFv (LH) <400> 7 accgtggccc aggcggccga tattcagatg acgcagtcac cgtcctcgct tagcgcttct 60 gttggtgatc gtgttaccat aacgtgtcgg gcaagtcagg atgttaatac agcggtagcg 120 tggtatcaac aaaagcccgg taaagcacct aaattgctta tttattcggc atctttttta 180 tatagcggtg ttccatcacg cttctctggt tcccgtagcg gtactgactt tactctgaca 240 atttcctcac tgcagcctga agatttcgct acatactact gccagcagca ttataccact 300 ccaccgacgt ttggtcaagg taccaaagtt gaaataaaag gtggtggtgg tagcggtgga 360 ggtggtagtg gtggtggtgg ttccgaagta caattagttg aaagtggtgg tggactggta 420 cagcctggtg gttcactccg tttgagctgc gctgctagcg gatttaacat taaagacacg 480 tacatccact gggttcgaca ggcaccggga aaaggtttag agtgggttgc ccgcatctat 540 ccgacaaatg gttacactcg ttatgcggat tcagttaaag gaagatttac catttctgca 600 gatacatcta agaacactgc atatctgcaa atgaatagtt tacgtgcaga ggataccgca 660 gtgtattatt gtagtcgttg gggtggcgat ggtttctacg caatggatta ttggggtcag 720 ggaacactgg ttaccgtctc gggtggaggt ggttcaggtg gtggtggtag tggtggtggt 780 ggttctggcc aggccggcca gcacgcggcc 810 <210> 8 <211> 33 <212> DNA <213> Artificial Sequence <220> <223> primer <400> 8 gggaattcca tatgaccgtg gcccaggcgg ccg 33 <210> 9 <211> 36 <212> DNA <213> Artificial Sequence <220> <223> primer <400> 9 cgcggatccg ctgccggccg cgtgctggcc ggcctg 36 <210> 10 <211> 812 <212> DNA <213> Artificial Sequence <220> <223> scFv (HL) <400> 10 accgtggccc aggcggccga agtgcagtta gtcgaatccg gtggaggctt agttcagcct 60 ggtggcagcc ttcgtctgtc atgcgctgct tctggtttta acatcaaaga tacttatatc 120 cactgggtac ggcaggcccc aggaaaaggt ctggaatggg tggcccgtat ttatcccact 180 aatggatata cccgttatgc cgactcagta aaaggtcgtt tcactatttc ggcagatact 240 agtaaaaata cagcttatct gcaaatgaac tctctcagag cagaggatac cgcggtttat 300 tattgttctc gctggggtgg tgatggtttc tatgctatgg attattgggg tcaaggtact 360 ttggttacgg tgtctggtgg tggtggttca ggcggaggtg gtagtggtgg tggaggtagc 420 gacattcaga tgacgcaatc tcctagcagt ctttcagcga gtgtcggtga tcgtgtcacc 480 attacatgtc gtgcatcaca agatgttaat accgcagtgg cgtggtatca gcagaagccg 540 ggtaaagcac cgaaattgct gatatattcc gcctcattct tatatagcgg tgttccttct 600 cgctttagcg gatcgcgaag cggaacagac tttaccctga caatatcgtc tctgcagccg 660 gaggattttg caacgtatta ttgccaacag cattatacaa ccccaccgac ctttggtcag 720 ggtacgaaag tagaaattaa gggtggaggt ggttccggtg gtggtggtag tggtggaggt 780 ggtagtggcc aggccggcca gcacgcggcc gc 812 <210> 11 <211> 38 <212> DNA <213> Artificial Sequence <220> <223> primer <400> 11 gggaattcca tatgaccgtg gcccaggcgg ccgaagtg 38 <210> 12 <211> 36 <212> DNA <213> Artificial Sequence <220> <223> primer <400> 12 cgcggatccg ctgccggccg cgtgctggcc ggcctg 36 <210> 13 <211> 816 <212> DNA <213> Artificial Sequence <220> <223> scFv (LH) <400> 13 catatggata tccagggac acagtccccc agttcactgt ccgcgtccgt tggggaccgt 60 gtcaccatta cctgtcgcgc cagtcaagac gttagcacgg cggtcgcgtg gtaccagcaa 120 aagccaggga aggcgccaaa actgctgatc tatagcgcga gcttcctcta cagcggagtc 180 cccagtaggt tctccggatc ggggtccggc acggacttca ccttgaccat ctccagcctc 240 cagccggagg atttcgctac gtactactgc cagcagagct acacgacgcc gcccaccttc 300 ggccaaggca ccaaggtgga gataaaacgt acggttggtg gtggtggtag cggtggaggt 360 ggtagtggtg gtggtggttc cgaagtccag ttggtggagt ccggtggtgg cctggtccaa 420 ccgggtggga gtctcaggct ctcctgcgcc gcttcagggt tcacaatctc tgactattgg 480 attcactggg tgcgccaggc gccaggcaag gggctggagt gggtcgcggg cattaccccg 540 gcgggcggct acacctatta cgccgactca gtcaagggcc gcttcacaat ctccgcggac 600 accagcaaga acaccgcgta cctccaaatg aactcgctgc gcgccgaaga caccgccgtg 660 tactattgcg cgagattcgt gttcttcctg ccgtacgcca tggactactg gggccaggga 720 acgctggtga ccgtgagtag ttcgggtgga ggtggttcag gtggtggtgg tagtggtggt 780 ggtggttctg gccaggccgg ccagcacgcg ggatcc 816 <210> 14 <211> 35 <212> DNA <213> Artificial Sequence <220> <223> primer <400> 14 gggaattcca tatggatatc cagatgacac agtcc 35 <210> 15 <211> 30 <212> DNA <213> Artificial Sequence <220> <223> primer <400> 15 ggtcgcggat cccgcgtgct ggccggcctg 30 <210> 16 <211> 816 <212> DNA <213> Artificial Sequence <220> <223> scFv (HL) <400> 16 catatggaag tccagttggt ggagtccggt ggtggcctgg tccaaccggg tgggagtctc 60 aggctctcct gcgccgcttc agggttcaca atctctgact attggattca ctgggtgcgc 120 caggcgccag gcaaggggct ggagtgggtc gcgggcatta ccccggcggg cggctacacc 180 tattacgccg actcagtcaa gggccgcttc acaatctccg cggacaccag caagaacacc 240 gcgtacctcc aaatgaactc gctgcgcgcc gaagacaccg ccgtgtacta ttgcgcgaga 300 ttcgtgttct tcctgccgta cgccatggac tactggggcc agggaacgct ggtgaccgtg 360 agtagtggtg gtggtggtag cggtggaggt ggtagtggtg gtggtggttc cgatatccag 420 atgacacagt cccccagttc actgtccgcg tccgttgggg accgtgtcac cattacctgt 480 cgcgccagtc aagacgttag cacggcggtc gcgtggtacc agcaaaagcc agggaaggcg 540 ccaaaactgc tgatctatag cgcgagcttc ctctacagcg gagtccccag taggttctcc 600 ggatcggggt ccggcacgga cttcaccttg accatctcca gcctccagcc ggaggatttc 660 gctacgtact actgccagca gagctacacg acgccgccca ccttcggcca aggcaccaag 720 gtggagataa aacgtacggt ttcgggtgga ggtggttcag gtggtggtgg tagtggtggt 780 ggtggttctg gccaggccgg ccagcacgcg ggatcc 816 <210> 17 <211> 35 <212> DNA <213> Artificial Sequence <220> <223> primer <400> 17 gggaattcca tatggaagtc cagttggtgg agtcc 35 <210> 18 <211> 33 <212> DNA <213> Artificial Sequence <220> <223> primer <400> 18 ggtcgcggat ccttacgcgt gctggccggc ctg 33 <210> 19 <211> 36 <212> DNA <213> Artificial Sequence <220> <223> primer <400> 19 gccgaggaga agcgctgcgg ctacgagcgt ctcctg 36 <210> 20 <211> 36 <212> DNA <213> Artificial Sequence <220> <223> primer <400> 20 caggagacgc tcgtagccgc agcgcttctc ctcggc 36 <210> 21 <211> 36 <212> DNA <213> Artificial Sequence <220> <223> primer <400> 21 actcacttcc tagattgcga agtgaagctt atcaag 36 <210> 22 <211> 36 <212> DNA <213> Artificial Sequence <220> <223> primer <400> 22 cttgataagc ttcacttcgc aatctaggaa gtgagt 36 <210> 23 <211> 36 <212> DNA <213> Artificial Sequence <220> <223> primer <400> 23 gaggcagccg tcaactgcct ggtcaatttg tacctg 36 <210> 24 <211> 36 <212> DNA <213> Artificial Sequence <220> <223> primer <400> 24 caggtacaaa ttgaccaggc agttgacggc tgcctc 36 <210> 25 <211> 36 <212> DNA <213> Artificial Sequence <220> <223> primer <400> 25 atgaaagctg ccatgtgcct ggagaaaaag ctgaac 36 <210> 26 <211> 36 <212> DNA <213> Artificial Sequence <220> <223> primer <400> 26 gttcagcttt ttctccaggc acatggcagc tttcat 36 <210> 27 <211> 36 <212> DNA <213> Artificial Sequence <220> <223> primer <400> 27 aaccaggccc ttttgtgcct tcatgccctg ggttct 36 <210> 28 <211> 36 <212> DNA <213> Artificial Sequence <220> <223> primer <400> 28 agaacccagg gcatgaaggc acaaaagggc ctggtt 36

Claims (22)

A fusion protein in which a single chain antibody fragment (scFv) is bound to ferritin.
The method according to claim 1,
Wherein said scFv is bound to the N-terminus or C-terminus of ferritin.
The method according to claim 1,
Wherein the scFv is either directly bound to ferritin or bound to ferritin through a peptide linker.
The method according to claim 1,
Wherein said scFv comprises a heavy chain fragment and a light chain fragment of an antibody.
5. The method of claim 4,
Wherein the heavy chain fragment and the light chain fragment are joined directly or through a peptide linker.
The method according to claim 1,
Wherein the ferritin is homologous or heterologous.
The method according to claim 1,
Wherein the ferritin is encoded by the polynucleotide of SEQ ID NO: 1.
8. A polynucleotide encoding the fusion protein of any one of claims 1 to 7.
9. An expression vector comprising the polynucleotide of claim 8.
9. A transformant in which the expression vector of claim 9 is introduced into a host.
(a) culturing the transformant of claim 10 to obtain a culture; And
(b) recovering a fusion protein in which the single chain antibody fragment (scFv) and ferritin are bound to the fusion protein from the culture.
(a) obtaining an expression vector by cloning a polynucleotide encoding a single chain antibody fragment (scFv) and a fusion protein in the form of binding of ferritin;
(b) introducing the obtained expression vector into a host cell to obtain a transformant; And
(c) culturing the transformant, and recovering the fusion protein from the transformant.
A nanocluster comprising the fusion protein of any one of claims 1 to 7.
14. The method of claim 13,
Wherein said fusion proteins are formed by self assembly.
14. The method of claim 13,
Wherein the nanoclust is spherical with a diameter of 10 to 30 nm.
A drug delivery system comprising the nanocluster of claim 13 and a drug.
17. The method of claim 16,
Wherein the drug is bound to the interior or surface of the nanocluster and is capable of target-directed drug delivery.
A diagnostic kit comprising the nanoclusters of claim 13.
A protein chip comprising the nanocluster of claim 13.
13. A method for detecting an antigen comprising the step of adding an isolated protein sample to the nanocluster of claim 13 to determine whether an antigen-antibody reaction occurs.
21. The method of claim 20,
Wherein the protein sample is blood, serum, plasma, body fluids, saliva, urine, intestinal fluid, lymph or peritoneal fluid isolated from a patient suspected of causing the disease.
22. The method of claim 21,
Wherein said disease is an infectious disease, a genetic disease or a metabolic disease.

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