139 results about "Inclusion bodies" patented technology

The invention discloses an oligopeptide composition for inhibiting inclusion body formation and promoting Gag-Like protein nanoparticle self-assembly, the oligopeptide composition comprises a C-terminal oligopeptide and an N-terminal oligopeptide, the amino acid sequence of the N-terminal oligopeptide is as shown in SEQ ID NO: 1, and the amino acid sequence of the C-terminal oligopeptide is as shown in SEQ ID NO: 2. The oligopeptide composition can effectively avoid formation of a prokaryotic expression protein inclusion body and / or promote dissolution of prokaryotic expression protein, the oligopeptide composition is further utilized to be combined with HIV-1p24 and human endogenous retrovirus K capsid protein CA, nanoparticles are prepared respectively, and the oligopeptide composition can be used as a carrier for antigen surface display or drug transportation. The nanoparticles formed by the HIV-1 capsid protein p24 and the human HERV K CA have cavities which are obviously larger than those of ferritin, so that the nanoparticles have higher loading capacity; as an antigen display platform, the antibody also has good stability and wide applicability.

The invention relates to the technical field of biology, in particular to a preparation method and application of a recombinant human long-acting interleukin-22 binding protein. The amino acid sequence of the recombinant human long-acting interleukin-22 binding protein is as shown in SEQ ID No. 1. According to the method for preparing the IL-22BP recombinant protein with high biological activity by utilizing an Escherichia coli prokaryotic expression system, a novel fusion protein is designed, a sequence for coding human IL-22BP is connected with a sequence for coding ABD to construct an IL-22BP-ABD fusion gene, the IL-22BP-ABD fusion gene is induced to be expressed in Escherichia coli, inclusion body protein is separated, and the IL-22BP recombinant protein with high biological activity is obtained. The target protein is obtained through denaturation, purification and renaturation, and the biological activity of the IL-22BP-ABD is verified through in-vivo and in-vitro experiments.

The invention relates to the technical field of biology, in particular to a recombinant fusion protein, polynucleotide for coding the recombinant fusion protein, a recombinant expression plasmid containing the polynucleotide, an engineered recombinant host cell and a method for preparing target polypeptide by using the recombinant fusion protein. The recombinant fusion protein comprises tag polypeptide-target polypeptide-(linker 1-linker x-linker 2-target polypeptide) n from N terminal to C terminal, x is the number of linkers, x is 0 or 1, n is a positive integer not less than 1, the tag polypeptide is SEQ ID NO.1 or SEQ ID NO.2, the linker 1 contains a Kex2 protease enzyme cutting site and a carboxypeptidase B enzyme cutting site, and the linker 1 contains a Kex2 protease enzyme cutting site and a carboxypeptidase B enzyme cutting site. And the connecting peptide 2 contains a WELQ protease enzyme cutting site. The recombinant fusion protein disclosed by the invention is expressed in an inclusion body form, the synthesis process is simplified, the target polypeptide can be prepared with high yield and high purity by using the recombinant fusion protein disclosed by the invention, and the production cost can be reduced from multiple dimensions.

The invention discloses an influenza C virus HEF protein polyclonal antibody preparation method, which comprises: carrying out signal peptide prediction, antigen epitope screening and hydrophobicity analysis through bioinformatics, constructing a recombinant prokaryotic expression vector pET32a-HEF by using a seamless cloning technology, and efficiently expressing the HEF protein in Escherichia coli to obtain the influenza C virus HEF protein polyclonal antibody. The inclusion body protein yield is improved by optimizing conditions; and purifying by nickel column affinity chromatography to obtain high-purity recombinant protein, emulsifying the high-purity recombinant protein and a Freund's adjuvant, immunizing a Japanese white rabbit, immunizing for three times, and collecting high-titer serum. The method breaks through detection limitation caused by antigen tag concealment in a eukaryotic expression system, the obtained polyclonal antibody is high in specificity, the eukaryotic expression HEF protein can be accurately recognized, and a key tool is provided for ICV virus-like particle identification, vaccine research and development and diagnosis technologies. Compared with a traditional method, the scheme is simple and convenient to operate, low in cost and high in antibody titer, and has remarkable application value.

The invention belongs to the technical field of biological medicine. The invention relates to a signal peptide, in particular to a signal peptide of GLP-1 and an analogue thereof and application thereof. The invention provides a signal peptide of a GLP-1 protein or an analogue thereof. The amino acid sequence of the signal peptide is shown as any one of SEQ ID NO.1-8. The signal peptide of the GLP-1 protein is improved, so that the signal peptide can promote the generation of an inclusion body and optimize the property of the inclusion body, and also can improve the unit yield of the target protein, and finally, the target protein can obtain more efficient expression. Besides, while the signal peptide is truncated, the base sequence of the target protein is optimized, the character of the inclusion body is changed, and the character of the inclusion body is further optimized. When the fusion protein is used for preparing the GLP-1 protein analogue, the proportion of the target protein in an inclusion body can be greatly improved while the original high inclusion body yield is ensured, the purpose of improving the productivity from the source is finally achieved, and the fusion protein has good application prospects and value.

The invention discloses a chicken infectious anemia subunit vaccine composition as well as a preparation method and application thereof. The vaccine composition contains a mixture of CIAV (Chicken Infectious Anemia Virus) VP1 and VP2 proteins, the mixture of the VP1 and VP2 proteins is prepared by performing in-vitro renaturation on VP1 inclusion body proteins by using a gradient dialysis method, adding pre-purified VP2 proteins in the dialysis process to promote the recovery of key conformation epitopes of the VP1 proteins, and then gradually removing a denaturing agent to obtain the VP1 and VP2 protein mixture. And refolding the VP1 protein to obtain the protein. The soluble VP2 protein is used as a molecular chaperone to recover the VP1 protein from the inclusion body. According to the VP2 protein assisted synergistic refolding strategy, the key conformation epitope of the VP1 protein is recovered by using the natural function of the VP2 protein. Subsequently, the immunogenicity and protective efficacy of the refolded VP1 and VP2 protein mixture are evaluated, and an economic and effective technical means is provided for preventing and controlling chicken infectious anemia.

The invention discloses a preparation method and application of GHK oligopeptide, and belongs to the technical field of biology. According to the method, a nucleotide sequence of the GHK polypeptide is obtained by designing tandem repeat GHK polypeptide ([GHK] 63) and combining preferred codons of bacillus subtilis to optimize a polypeptide coding gene. The GHK oligopeptide is subjected to recombinant expression in bacillus subtilis by utilizing a genetic engineering technology, the obtained recombinant protein is not easy to form an inclusion body and does not contain endotoxin, and the high-yield GHK oligopeptide is obtained after separation, purification and protease digestion treatment. According to the GHK oligopeptide preparation method provided by the invention, extra optimization treatment does not need to be carried out on tandem repeat GHK polypeptides, the yield of the GHK oligopeptide is improved, the whole production process is simplified, the cost is low, and the method is suitable for large-scale production of blue copper peptides and has wide application prospects in the fields of medicines, medical beauty and the like.

The invention discloses a preparation method and application of a cat main allergen FEL-1 nano antibody FEL-1-Nb, and relates to the technical field of antibody preparation, and the preparation method comprises the following steps: preparing an immunogen; animal immunization and library construction; constructing and panning a phage display library; screening and identifying positive clone; and expression and purification of the nano antibody: cloning the positively cloned VHH gene to an expression vector such as a pET series, transforming an expression strain such as escherichia coli BL21 (DE3), carrying out IPTG induced expression, and purifying through an inclusion body purification method to obtain a high-purity nano antibody protein. The nano antibody FEL-1-Nb provided by the invention can be specifically bound with a cat main allergen FEL-1 protein, the unique amino acid sequence of the nano antibody FEL-1-Nb is shown as SEQIDNO: 1, high-affinity binding with the FEL-1 protein is ensured, the positive clone binding rate is high through phage display panning and ELISA verification, the phage recovery rate after the third round of panning is increased by more than 1000 times compared with the first round of panning, and the positive clone binding rate is higher than that of the first round of panning. Therefore, the nano antibody has excellent targeted recognition capability.

The invention belongs to the technical field of biological detection, and particularly relates to a preparation method of lipopolysaccharide-beta-1, 3-glucan binding protein and application of the lipopolysaccharide-beta-1, 3-glucan binding protein in preparation of a broad-spectrum colloidal gold detection product for dermatophytes. The prokaryotic expression system induces the procambarus clarkii-sourced lipopolysaccharide-beta-1, 3-glucan binding protein to be efficiently expressed in an inclusion body form, the optimized inclusion body purification-renaturation process is combined to realize batch preparation, and the colloidal gold chromatography technology is integrated, so that the procambarus clarkii-sourced lipopolysaccharide-beta-1, 3-glucan binding protein is obtained. The bottlenecks of the traditional detection method in sensitivity, broad spectrum and field applicability are broken through.

The invention provides a human urate oxidase mutant as well as a preparation method and application thereof. The amino acid sequence of the mutant is as shown in SEQ ID NO.1 in a sequence table. The preparation method comprises the following steps: (a) denaturation pretreatment of an inclusion body; (b) denaturation of the inclusion body; and (c) a protein renaturation method is adopted, the preparation process does not need a column chromatography step, the production cost is saved, and the obtained mutant protein is relatively high in purity, has urate oxidase activity, can be used for oxydative degradation of uric acid, and has important clinical application value.

The invention discloses an optimized recombinant chicken double-cell factor as well as a preparation method and application thereof. The chicken recombinant double-cell factor coding gene provided by the invention contains complete ChIL-2 and ChIFN-alpha structures. The preparation process comprises the following steps: selecting a pichia pastoris expression system; optimizing the recombinant chicken double-cell factor according to the codon preference of pichia pastoris; inserting the optimized gene sequence into an expression vector, and introducing host bacteria to construct a recombinant yeast engineering strain; carrying out inoculated culture by using the obtained recombinant yeast, and screening strains containing target protein based on expression level to obtain required culture bacteria; and breeding and culturing the obtained high-expression-level culture bacteria. According to the invention, ChIL-2 and ChIFN-alpha are connected through a modified flexible linker, and a nucleotide sequence is replaced by preferred codons of pichia pastoris, so that a chicken recombinant cell factor can be secreted to a supernatant, the defect of ChIL-2 expression quantity is overcome, and the problem that proteins of ChIL-2 and ChIFN-alpha mainly exist in bacteria and inclusion bodies in prokaryotic expression is solved.

Provided herein are methods for producing peptides from inclusion bodies. Also provided herein are onconase variants with improved properties.

The invention discloses a recombinant full-length human-derived III-type collagen as well as a preparation method and application of the recombinant full-length human-derived III-type collagen. The method comprises the following steps: replacing at least one corresponding rare codon of glycine, proline, arginine, leucine, isoleucine, valine and / or glutamic acid host bacteria in a Gly-Pro-X or Gly-X-Pro tripeptide structure coded by a wild full-length human III-type collagen gene sequence with a synonymous codon used by the host bacteria at high frequency; the translation efficiency in prokaryotic systems such as escherichia coli is obviously improved; the method comprises the following steps: designing 6-12 gene segments with overlapping sequences, splicing by adopting an overlapping extension PCR (Polymerase Chain Reaction) technology to obtain a full-length optimized gene, constructing the full-length optimized gene to an expression vector, and transforming the full-length optimized gene into host bacteria for induced expression; the expression product exists in the form of an inclusion body, and the natural conformation of the expression product is recovered through in-vitro renaturation; according to the method, high-efficiency expression and active preparation of the full-length human-derived III-type collagen in a prokaryotic system are realized.

The invention relates to the technical field of aquatic animal immune regulation and control, in particular to rHoLL-like stepped lectin-like recombinant protein as well as a preparation method and application thereof. The recombinant protein has pathogen-related molecular pattern recognition and combination capabilities, can promote aggregation of pathogens in a body fluid environment, and activates an aquatic animal complement system, so that the non-specific immune defense capability is enhanced. The preparation method comprises the following steps: amplifying a HoLL-like mature peptide coding sequence, constructing a recombinant expression vector, and converting the recombinant expression vector into an escherichia coli expression host for induced expression to obtain rHoLL-like lectin-like recombinant protein existing in an inclusion body form; and carrying out affinity chromatography purification on the inclusion body protein, and carrying out renaturation treatment in a manner of gradient reduction of denaturant concentration to obtain the rHoLL-like stepped lectin-like recombinant protein. The rHoLL-like stepped lectin-like recombinant protein has good biological safety, and can be applied to aquaculture as an aquatic animal immunopotentiator or a related biological product.

The present application belongs to the field of biotechnology, and particularly relates to a carboxypeptidase B (CPB) precursor gene sequence, a recombinant carboxypeptidase B precursor and a preparation method of carboxypeptidase B. The carboxypeptidase B precursor gene sequence is shown in SEQ ID No. 6, the amino acid sequence is shown in SEQ ID No. 5, the gene sequence of the CPB enzyme is shown in SEQ ID No. 2, and the amino acid sequence is shown in SEQ ID No. 4. The preparation method of CPB comprises the following steps: (1) cloning and construction of a CPB enzyme expression vector; (2) expression of CPB precursor protein by using an engineering bacterium to form an inclusion body; (3) washing, crushing and centrifugation of the bacterium, collection of the inclusion body, denaturation and dissolution; (4) renaturation of the inclusion body; and (5) CPB activation and purification. The process steps of the present application are simple, animal pancreas is not used, and the possibility of infection is reduced; the specific activity of the obtained CPB enzyme is high, the yield per liter of fermentation liquid is high, and the present application is suitable for large-scale production and application.

The invention belongs to the technical field of gene engineering, and particularly provides a recombinant virus vector capable of being directly fed and infected, the recombinant virus vector takes polyhedrosis virus as a skeleton, and comprises a nucleotide sequence for coding a target protein and a nucleotide sequence for coding an exogenous polyhedrosis virus polyhedrosis protein. According to the recombinant virus vector provided by the invention, infection can be initiated only by ingesting a plurality of virus-embedded polyhedrosis by insect larvae, the expression yield of target protein is obtained to the maximum extent, and enough inclusion bodies with polyhedrosis can be obtained for infecting the insect larvae. The insect expression protein has conformation closer to that of mammals, and the applicability of the protein is improved. The invention further provides a production method of the target protein, a protein expression place is transferred from insect cell culture in a culture dish to insect larva direct culture, the cost is low, the technical difficulty in the large-scale production process is greatly reduced, and the protein production cost is low.

The invention relates to construction of a fusion antibacterial peptide expression vector as well as an expression purification method and a purification device thereof, and belongs to the technical field of bioengineering. The preparation method comprises the following steps: fusing an antibacterial peptide to a C terminal of RNase denaturation form Onconase (ONC) protein from Rana pipiens, constructing an expression plasmid, and transforming the expression plasmid into escherichia coli to obtain gt; the yield of the inclusion body form fusion peptide is 300 mg / L. Gt is realized through operations of inclusion body washing, redissolving, acid hydrolysis, neutralization and the like; and the low-cost large-scale production of the 95% high-purity antibacterial peptide is realized. As a carrier protein, ONC has the advantages of high expression quantity, low toxicity, small molecular weight, specific pH solubility and the like. In the purification process, the inclusion body is dissolved by using a urea solution, and the purity and the yield of the antibacterial peptide are further improved by combining cation exchange chromatography and an ultrafiltration technology. According to the method and the device, the purification efficiency is remarkably improved, the labor investment is reduced, and the method and the device are suitable for wide industrial application.

The invention provides a fish creatine kinase sensitization and immune cross reactivity analysis method which comprises the following steps: preparing a fish muscle water-soluble protein crude extract, separating 40-45kDa protein components in the fish muscle crude extract through SDS-PAGE (sodium dodecyl sulfate polyacrylamide gel electrophoresis), and screening a target sensitization protein combined with IgE / IgG through immunoblotting; the method comprises the following steps: extracting total RNA of grass carp and synthesizing cDNA, designing a creatine kinase specific primer for amplification to obtain a creatine kinase gene sequence, and carrying out bioinformatics analysis after sequencing verification; the method comprises the following steps: cloning a creatine kinase gene to an expression vector, transforming escherichia coli BL21, performing IPTG induced expression, and performing urea gradient dialysis renaturation on an inclusion body to obtain the recombinant grass carp creatine kinase. Detecting the IgE binding activity of the recombinant grass carp creatine kinase and the serum of the allergic patient through dot hybridization; the IgG cross reactivity of the recombinant grass carp creatine kinase and the blue crab arginine kinase is verified through indirect ELISA; the IgE cross reaction degree of the recombined grass carp creatine kinase and the blue crab arginine kinase is quantified through inhibitory dot hybridization.

This invention belongs to the field of genetic engineering. By introducing a TC tag between amino acids 199 and 200 of the wild-type bluetongue virus non-structural protein NS2, a recombinant virus was rescued. Analysis of viral plaques and growth curves revealed that the recombinant virus formed plaques of similar size to the wild-type virus, and their growth curves showed no significant difference. Immunofluorescence and FlasH-EDT2 staining of NS2 showed that the fluorescence of NS2 labeled with anti-NS2 antibody overlapped with that labeled with FlasH-EDT2. Three-dimensional imaging of FlasH-EDT2-labeled NS2 revealed that the viral inclusion bodies exhibited fluorescence around the periphery but no fluorescence inside, displaying an overall "core-shell" hierarchical structure. This recombinant bluetongue virus can be used for tracing and localizing NS2 protein and viral inclusion bodies in living cells, and can also be applied to BTV neutralization assays, antiviral drug screening, and other related research.

This specification describes compounds, compositions, and methods for regulating inclusion body formation and stress granule formation in cells in connection with the development of neurodegenerative diseases, musculoskeletal diseases, cancer, ophthalmic diseases, and viral infections. In another embodiment, the disclosure provides a pharmaceutical composition comprising a pharmaceutically acceptable carrier and one of the compounds of the embodiments described above. Another embodiment is a method for treating a subject having a neurodegenerative disease or disorder, comprising administering a pharmaceutically effective amount of one of the pharmaceutical compositions or compounds of the embodiments described above to a subject in need thereof.

The application discloses active aggregation peptides and application thereof, and belongs to the technical field of bioengineering. The active aggregation peptides are derived from alpha-hemolysin HlyA of Escherichia coli CFT073, and comprise five sequences, namely HlyA218, HlyA60, H12, H1 and H2. The active aggregation peptides can mediate the active inclusion body formation of a target protein in a host cell by being fused with the target protein for expression, and the short peptides have high protein activity aggregation rate and the potential of stimulating the rapid growth of a recombinant bacterium. The active aggregation peptides can be applied to column-free purification and in-situ immobilization of a recombinant protein, and have low production cost and simple steps.

To provide a pharmaceutical formulation comprising trehalose for use in treating myopathies, neurodegenerative diseases, or tauopathies associated with abnormal protein aggregation.SOLUTION: A pharmaceutical formulation comprising a therapeutically effective amount of trehalose is provided, wherein the pharmaceutical formulation is for use in a method for treating a disease associated with abnormal protein aggregation and / or inclusion bodies formation in myocytes, neurons, or extracellular compartments, or for alleviating at least one symptom associated therewith in a human subject in need thereof, the method comprising intravenously administering to the subject a pharmaceutical formulation comprising 0.1% (w / v) to 50% (w / v) of trehalose. An injectable aqueous pharmaceutical formulation comprising a therapeutically effective amount of trehalose is also provided.SELECTED DRAWING: None

The invention relates to a TCEP-based recombinant proinsulin inclusion body denaturation and renaturation method, according to the method, TCEP is added as a reducing agent in the denaturation and renaturation process, compared with the prior art, the yield of proinsulin denaturation and renaturation is increased, and the yield of insulin is remarkably increased. Besides, TCEP is high in reducibility, wide in applicable pH range and extremely low in toxicity, so that the production efficiency and the process stability of the recombinant insulin production process can be remarkably improved, the harm to operators and the environment is reduced, and the requirements of green chemistry and safe production are met.

The present invention discloses a Thermobifida fusca cutinase mutant and a method for its soluble expression, belonging to the technical field of enzyme engineering. In the present invention, the mutant D204C / E253C and the periplasmic protein disulfide isomerase DsbC are co-expressed in the Escherichia coli mutant strain E. coli Origami B(DE3). However, during the expression process of the obtained recombinant strain E. coli Origami B(DE3) / pSCDsbC-D204C / E253C, it is prone to misfolding to form a large number of inclusion bodies, and the soluble expression ratio is extremely low. The present invention further realizes the efficient soluble expression of the cutinase mutant D204C / E253C through co-expression with the molecular chaperone protein DsbC in the Escherichia coli mutant strain E. coli Origami B(DE3), and has certain industrial application prospects.

The application provides a bone morphogenetic protein BMP-2 recombinant protein, and the amino acid sequence of the BMP-2 recombinant protein is shown as SEQ ID No. 1. The coding gene, the expression plasmid, the prokaryotic expression vector and the prokaryotic expression method are also disclosed. The prokaryotic expression system is adopted, and a solubilization tag is creatively introduced, so that the inclusion body expression is converted into soluble expression. The BMP-2 is expressed in the form of inclusion body in the prokaryotic system, the protein is converted into soluble expression by adding the solubilization tag, the difficulty of protein separation and purification is reduced, the purification cycle is shortened, and the purification efficiency is improved.

This application relates to the biomedical field, specifically to a method for expressing tandem recombinant proteins using *E. coli*. The tandem recombinant protein has the general formula leader peptide-(cleavage site 1-spacer peptide-cleavage site 2-target protein)n, wherein the leader peptide is selected from any sequence of SEQ ID NO:1-4; cleavage sites 1 and 2 may be the same or different, and are double cleavage sites of Kex2 and CPB enzymes selected from dipeptides KR or RR; the spacer peptide is any sequence selected from tripeptide EDG, tetrapeptide SEQ ID NO:5-7, or heptapeptide SEQ ID NO:8; the target protein is GLP-1 or an analogue thereof; and n is a tandem repeat number of 2-10. The inclusion bodies obtained by this method do not require denaturation, and the target polypeptide is obtained through double enzyme digestion. The expression level of the fusion protein can reach 32 g / L, and the yield of the target polypeptide can reach 25.3 mg / g wet cells or 10 g / L fermentation broth.

The application discloses a fermentation method for producing thiamine pyrophosphokinase and belongs to the technical field of bioengineering. The BL21 recombinant engineering bacteria containing pET28a-TPK, pET28a-ProS2-TPK or pET28a-SUMO-TPK are constructed, the seed liquid is prepared, the isopropyl-beta-D-thiogalactoside is used for inducing expression, the bacteria are collected, the cells are broken and the supernatant is collected to obtain the TPK crude enzyme liquid. In the fermentation, the LB / TB culture medium containing 50 μg / mL kanamycin or 100 μg / mL ampicillin is used. The SUMO label is introduced to guide the correct folding of the TPK, so that the soluble expression ratio of the TPK is more than 85%, the ratio is improved by 2 times compared with the common system, the inclusion body ratio is greatly reduced, the process is stable and has good repeatability, and an effective scheme is provided for the industrialized large-scale preparation of the TPK.

The application discloses a fusion protein and application thereof in preparation of semaglutide precursor polypeptide, wherein N (N>=1) semaglutide fragments GLP-1 (11-37) are connected through KR, and then sequentially fused with an enterokinase enzyme cutting site and a fusion protein label to realize tandem expression, so that the fusion protein is a fusion protein label-enzyme cutting site-N associated semaglutide fragment GLP-1 (11-37), and the fusion protein label is an albumin affinity peptide (SEQ ID NO. 1). The fusion protein is expressed in a heterologous manner in an E. coli BL21 (DE3) competent cell, an engineering strain is constructed, and then fermentation expression is carried out by using a flask, so that the fermentation density of the bacterial body is greatly improved, expression of the target protein in an inclusion body is promoted, the yield of the target protein is improved, and the fusion protein has a good industrial application prospect. The fusion protein can be successfully recognized and cut by commercial enterokinase, KEX2 enzyme and carboxypeptidase B to release the semaglutide precursor polypeptide.

The invention discloses a bifunctional protein tag for improving thermal stability and solubility of recombinant protein, a product based on the bifunctional protein tag and application of the bifunctional protein tag, and belongs to the technical field of protein engineering. The amino acid sequence of the bifunctional tag is shown as SEQ ID NO: 1, the bifunctional tag has the similarity of 70%-95% or above, and the amino acid sequence variation mainly exists but is not limited to a secondary structure position. The bifunctional tag can be used at an N terminal or a C terminal of a target protein, and is suitable for expression and purification of a fusion protein in a prokaryotic expression system. The hydrophobic region of the natural protein is transformed through rational design, so that the technical problems that the existing protein tag is large in molecular weight and easy to shield the active structural domain of the target protein, and the residual non-natural amino acid after the tag is removed possibly destroys the correct folding of the protein are solved; the solubility and the thermal stability of the fusion protein in an escherichia coli expression system are remarkably improved, and the method is suitable for functional expression and industrial application of inclusion body protein.

The present application relates to the field of genetic engineering and biological enzyme depolymerization of PET plastics, and particularly relates to a hydrophilic PET depolymerase mutant and application thereof. The present application obtains a hydrophilic PET depolymerase mutant V68R, or A137R or I243R by mutating the 68th, or 137th, or 243th amino acid residue of the PETase protein amino acid sequence into R. Compared with the wild-type PETase protein, under the premise of ensuring the depolymerization efficiency of PET / BHET and effectively depolymerizing PET / BHET, the expression level of soluble protein is improved, and the formation of inclusion bodies is reduced in the expression system of Escherichia coli, Bacillus subtilis or Pichia pastoris, which has economic feasibility, PETase high-yield universality, and wide application prospect.