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Song X, Chu T, Shi W, He J. Expression, characterization, and application of human-like recombinant gelatin. BIORESOUR BIOPROCESS 2024; 11:69. [PMID: 39014092 PMCID: PMC11252100 DOI: 10.1186/s40643-024-00785-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Accepted: 07/04/2024] [Indexed: 07/18/2024] Open
Abstract
Gelatin is a product obtained through partial hydrolysis and thermal denaturation of collagen, belonging to natural biopeptides. With irreplaceable biological functions in the field of biomedical science and tissue engineering, it has been widely applied. The amino acid sequence of recombinant human-like gelatin was constructed through a newly designed hexamer composed of six protein monomer sequences in series, with the minimum repeating unit being the characteristic Gly-X-Y sequence found in type III human collagen α1 chain. The nucleotide sequence was subsequently inserted into the genome of Pichia pastoris to enable soluble secretion expression of recombinant gelatin. At the shake flask fermentation level, the yield of recombinant gelatin is up to 0.057 g/L, and its purity can rise up to 95% through affinity purification. It was confirmed in the molecular weight determination and amino acid analysis that the amino acid composition of the obtained recombinant gelatin is identical to that of the theoretically designed. Furthermore, scanning electron microscopy revealed that the freeze-dried recombinant gelatin hydrogel exhibited a porous structure. After culturing cells continuously within these gelatin microspheres for two days followed by fluorescence staining and observation through confocal laser scanning microscopy, it was observed that cells clustered together within the gelatin matrix, exhibiting three-dimensional growth characteristics while maintaining good viability. This research presents promising prospects for developing recombinant gelatin as a biomedical material.
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Affiliation(s)
- Xiaoping Song
- Department of Pharmacy, Anhui Medical College, Hefei, Anhui, 230061, China.
| | - Tao Chu
- Department of Pharmacy, Anhui Medical College, Hefei, Anhui, 230061, China
| | - Wanru Shi
- Department of Pharmacy, Anhui Medical College, Hefei, Anhui, 230061, China
| | - Jingyan He
- Department of Pharmacy, Anhui Medical College, Hefei, Anhui, 230061, China
- Anhui Engineering Research Center of Recombinant Protein Pharmaceutical Biotechnology, Hefei, Anhui, 230022, China
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Lerner A, Benzvi C, Vojdani A. The Frequently Used Industrial Food Process Additive, Microbial Transglutaminase: Boon or Bane. Nutr Rev 2024:nuae087. [PMID: 38960726 DOI: 10.1093/nutrit/nuae087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/05/2024] Open
Abstract
Microbial transglutaminase (mTG) is a frequently consumed processed food additive, and use of its cross-linked complexes is expanding rapidly. It was designated as a processing aid and was granted the generally recognized as safe (GRAS) classification decades ago, thus avoiding thorough assessment according to current criteria of toxicity and public health safety. In contrast to the manufacturer's declarations and claims, mTG and/or its transamidated complexes are proinflammatory, immunogenic, allergenic, pathogenic, and potentially toxic, hence raising concerns for public health. Being a member of the transglutaminase family and functionally imitating the tissue transglutaminase, mTG was recently identified as a potential inducer of celiac disease. Microbial transglutaminase and its docked complexes have numerous detrimental effects. Those harmful aspects are denied by the manufacturers, who claim the enzyme is deactivated when heated or by gastric acidity, and that its covalently linked isopeptide bonds are safe. The present narrative review describes the potential side effects of mTG, highlighting its thermostability and activity over a broad pH range, thus, challenging the manufacturers' and distributers' safety claims. The national food regulatory authorities and the scientific community are urged to reevaluate mTG's GRAS status, prioritizing public health protection against the possible risks associated with this enzyme and its health-damaging consequences.
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Affiliation(s)
- Aaron Lerner
- Research Department, Chaim Sheba Medical Center, The Zabludowicz Research Center for Autoimmune Diseases, 52621 Tel Hashomer, Israel
| | - Carina Benzvi
- Research Department, Chaim Sheba Medical Center, The Zabludowicz Research Center for Autoimmune Diseases, 52621 Tel Hashomer, Israel
| | - Aristo Vojdani
- Research Department, Immunosciences Lab., Inc., Los Angeles, CA 90035, USA
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Aqeel SM, Abdulqader AA, Du G, Liu S. Integrated strategies for efficient production of Streptomyces mobaraensis transglutaminase in Komagataella phaffii. Int J Biol Macromol 2024; 273:133113. [PMID: 38885870 DOI: 10.1016/j.ijbiomac.2024.133113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 05/21/2024] [Accepted: 06/10/2024] [Indexed: 06/20/2024]
Abstract
Transglutaminase (TGase) from Streptomyces mobaraensis commonly used to improve protein-based foods due to its unique enzymatic reactions, which imply considerable attention in its production. Recently, TGase exhibit broad market potential in non-food industries. However, achieving efficient synthesis of TGase remains a significant challenge. Herein, we achieved a substantial amount of a fully functional and kinetically stable TGase produced by Komagataella phaffii (Pichia pastoris) using multiple strategies including Geneticin (G418) screening, combinatorial mutations, promoter optimization, and co-expression. The active TGase expression reached a maximum of 10.1 U mL-1 in shake flask upon 96 h of induction, which was 3.8-fold of the wild type. Also, the engineered strain exhibited a 6.4-fold increase in half-life and a 2-fold increase in specific activity, reaching 172.67 min at 60 °C (t1/2(60 °C)) and 65.3 U mg-1, respectively. Moreover, the high-cell density cultivation in 5-L fermenter was also applied to test the productivity at large scale. Following optimization at a fermenter, the secretory yield of TGase reached 47.96 U mL-1 in the culture supernatant. Given the complexity inherent in protein expression and secretion, our research is of great significance and offers a comprehensive guide for improving the production of a wide range of heterologous proteins.
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Affiliation(s)
- Sahibzada Muhammad Aqeel
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, China; School of Biotechnology and Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, China
| | - Al-Adeeb Abdulqader
- School of Biotechnology and Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, China
| | - Guocheng Du
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, China; School of Biotechnology and Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, China; The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, China.
| | - Song Liu
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, China; School of Biotechnology and Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, China.
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Li Z, Xing S, Liu J, Wu X, Zhang S, Ma D, Liu X. Chaperonin co-expression and chemical modification enables production of active microbial transglutaminase from E. coli cytoplasm. Int J Biol Macromol 2023; 253:127355. [PMID: 37838118 DOI: 10.1016/j.ijbiomac.2023.127355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 09/21/2023] [Accepted: 09/30/2023] [Indexed: 10/16/2023]
Abstract
Microbial transglutaminase (MTG) is a usable enzyme for biomacromolecule modification. In the present study, a "molecular chaperonin" strategy was developed to produce MTG in E. coli cytoplasm with high expression level and a "small molecule-mediated chemical modification" strategy was adopted to strip propeptide chaperonin efficiently during purification. Propeptide (Pro) was expressed separately as a chaperonin to facilitate MTG expression in E. coli cytoplasm with a yield up to 300 mg or about 9 kU from 1 L fed-batch culture. Furthermore, small molecular chemicals were applied to interfere the interaction between MTG and Pro. Chemical acetylation was identified as a suitable method to strip Pro resulting in pure MTG with high specific activity up to 49.6 U/mg. The purified acetylated MTG was characterized by MS analysis. The deconvoluted mass and Peptide Sequence Tags analysis confirmed acetylation on amino groups of MTG protein. Finally, the applications of obtained MTG were demonstrated via protein polymerization of bovine serum albumin and PEGylation of human interferon-α2b. Our method provides MTG with high purity and specific activity as well as unique merit with masked amino groups thus avoiding self-polymerization and cross-linking between MTG and substrates.
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Affiliation(s)
- Zitao Li
- National Glycoengineering Research Center, NMPA Key Laboratory for Quality Research and Evaluation of Carbohydrate-Based Medicine, and Shandong Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Qingdao 266237, Shandong, China
| | - Shuang Xing
- National Glycoengineering Research Center, NMPA Key Laboratory for Quality Research and Evaluation of Carbohydrate-Based Medicine, and Shandong Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Qingdao 266237, Shandong, China
| | - Jing Liu
- National Glycoengineering Research Center, NMPA Key Laboratory for Quality Research and Evaluation of Carbohydrate-Based Medicine, and Shandong Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Qingdao 266237, Shandong, China; School of Pharmacy, Jining Medical University, 669 Xueyuan Road, Rizhao 276826, China
| | - Xiaocong Wu
- National Glycoengineering Research Center, NMPA Key Laboratory for Quality Research and Evaluation of Carbohydrate-Based Medicine, and Shandong Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Qingdao 266237, Shandong, China
| | - Sichao Zhang
- National Glycoengineering Research Center, NMPA Key Laboratory for Quality Research and Evaluation of Carbohydrate-Based Medicine, and Shandong Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Qingdao 266237, Shandong, China
| | - Di Ma
- National Glycoengineering Research Center, NMPA Key Laboratory for Quality Research and Evaluation of Carbohydrate-Based Medicine, and Shandong Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Qingdao 266237, Shandong, China
| | - Xianwei Liu
- National Glycoengineering Research Center, NMPA Key Laboratory for Quality Research and Evaluation of Carbohydrate-Based Medicine, and Shandong Key Laboratory of Carbohydrate Chemistry and Glycobiology, Shandong University, Qingdao 266237, Shandong, China.
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Fang K, Ma J, Wang X, Xu Z, Zhang Z, Li P, Wang R, Wang J, Sun C, Dong Z. Flow-cytometric cell sorting coupled with UV mutagenesis for improving pectin lyase expression. Front Bioeng Biotechnol 2023; 11:1251342. [PMID: 37720319 PMCID: PMC10502208 DOI: 10.3389/fbioe.2023.1251342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2023] [Accepted: 08/23/2023] [Indexed: 09/19/2023] Open
Abstract
Introduction: Alkaline pectin lyase is an important enzyme with a wide range of applications in industrial production, It has been widely used in many important fields such as fruit juice processing and extraction, the dyeing and processing of cotton and linen textiles, degumming plant fibers, environmental industrial wastewater treatment, and pulp and paper production. PGLA-rep4 was previously generated as a modified alkaline pectin lyase with high specific activity at pH 11.0°C and 70°C. However, the pre-constructed high-activity pectin lyase expression strains are still difficult to apply in industrial production due to their limited enzymatic activity. We hope to solve these problems by combining modern breeding techniques with high-throughput equipment to rapidly screen alkaline pectin lyase with higher enzymatic activity and lower cost. Methods: We fused the genes encoding PGLA-rep4 and fluorescent protein egfp using a flexible linker peptide and ligated them into a temperature-sensitive plasmid, pKD46. The constructed screening plasmid pKD46-PGLA-rep4-egfp was then transformed into an expression host and screened via flow-cytometric cell sorting coupled with UV mutagenesis. Results: Following mutagenesis, primary screening, and secondary screening, the high-expression strain, named Escherichia coli BL21/1G3, was obtained. The screening plasmid pKD46-PGLA-rep4-egfp was eliminated, and the original expression plasmid pET28a-PGLA-rep4 was then retransformed into the mutant strains. After induction and fermentation, pectin lyase activity in E. coli BL21/1G3 was significantly increased (1.37-fold relative to that in the parental E. coli BL21/PGLA-rep4 strain, p < 0.001), and the highest activity was 230, 240 U/mL at 144 h. Genome sequencing revealed that genes encoding ribonuclease E (RNase E) and diadenosine tetraphosphatase (ApaH) of E. coli BL21/1G3 were mutated compared to the sequence in the original E. coli BL21 (DE3) strain, which could be associated with increased enzyme expression. Discussion: Our work provides an effective method for the construction of strains expressing pectin lyase at high levels.
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Affiliation(s)
- Ke Fang
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP), Qilu University of Technology, Jinan, Shandong, China
- School of Bioengineering, Qilu University of Technology, Jinan, Shandong, China
| | - Jun Ma
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP), Qilu University of Technology, Jinan, Shandong, China
- School of Bioengineering, Qilu University of Technology, Jinan, Shandong, China
| | - Xinyu Wang
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP), Qilu University of Technology, Jinan, Shandong, China
- School of Bioengineering, Qilu University of Technology, Jinan, Shandong, China
| | - Ziting Xu
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP), Qilu University of Technology, Jinan, Shandong, China
- School of Bioengineering, Qilu University of Technology, Jinan, Shandong, China
| | - Ziyang Zhang
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP), Qilu University of Technology, Jinan, Shandong, China
- School of Bioengineering, Qilu University of Technology, Jinan, Shandong, China
| | - Piwu Li
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP), Qilu University of Technology, Jinan, Shandong, China
- School of Bioengineering, Qilu University of Technology, Jinan, Shandong, China
| | - Ruiming Wang
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP), Qilu University of Technology, Jinan, Shandong, China
- School of Bioengineering, Qilu University of Technology, Jinan, Shandong, China
| | - Junqing Wang
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP), Qilu University of Technology, Jinan, Shandong, China
- School of Bioengineering, Qilu University of Technology, Jinan, Shandong, China
| | - Chuying Sun
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP), Qilu University of Technology, Jinan, Shandong, China
- School of Bioengineering, Qilu University of Technology, Jinan, Shandong, China
| | - Ziyang Dong
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP), Qilu University of Technology, Jinan, Shandong, China
- School of Bioengineering, Qilu University of Technology, Jinan, Shandong, China
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Shen ML, Ciou JY, Hsieh LS, Hsu CL. Recombinant Streptomyces netropsis transglutaminase expressed in Komagataella phaffii (Pichia pastoris) and applied in plant-based chicken nugget. World J Microbiol Biotechnol 2023; 39:200. [PMID: 37198411 DOI: 10.1007/s11274-023-03644-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Accepted: 05/07/2023] [Indexed: 05/19/2023]
Abstract
Transglutaminase (TG, EC 2.3.2.13) is widely used to modify functional properties in food systems, which can catalyze cross-linking reaction of proteins. In this work, microbial transglutaminase (MTG) from Streptomyces netropsis was heterologously expressed in the methylotrophic yeast Komagataella phaffii (Pichia pastoris). The specific activity of recombinant microbial transglutaminase (RMTG) was 26.17 ± 1.26 U/mg, and the optimum pH and temperature were measured as 7.0 and 50 °C, respectively. Bovine serum albumin (BSA) was used as a substrate to evaluate the effect of cross-linking reaction, and we found that RMTG had significant (p < 0.05) cross-linking effect for more than 30 min reactions. RMTG was further utilized in the investigation of plant-based chicken nuggets. Results showed that the hardness, springiness and chewiness of nuggets increased, and the adhesiveness decreased after RMTG treatment, which can prove that RMTG has the potential to improve the texture properties of plant-based chicken nuggets.
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Affiliation(s)
- Ming-Li Shen
- Department of Food Science, Tunghai University, Taichung, 407224, Taiwan
| | - Jhih-Ying Ciou
- Department of Food Science, Tunghai University, Taichung, 407224, Taiwan
| | - Lu-Sheng Hsieh
- Department of Food Science, Tunghai University, Taichung, 407224, Taiwan.
| | - Chuan-Liang Hsu
- Department of Food Science, Tunghai University, Taichung, 407224, Taiwan.
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Yildiz S, Solak K, Acar M, Mavi A, Unver Y. Magnetic nanoparticle mediated-gene delivery for simpler and more effective transformation of Pichia pastoris. NANOSCALE ADVANCES 2021; 3:4482-4491. [PMID: 36133460 PMCID: PMC9418747 DOI: 10.1039/d1na00079a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 06/05/2021] [Indexed: 06/16/2023]
Abstract
The introduction of exogenous DNA into a cell can be used to produce large quantities of protein. Here, we describe a novel gene delivery method for Pichia pastoris based on recombinant DNA delivery using magnetic nanoparticles (MNPs) under magnetic forces. For this purpose, a linear plasmid (pGKB-GFP) containing the Green Fluorescent Protein (GFP) gene is loaded on polyethyleneimine-coated iron oxide (Fe3O4@PEI) MNPs at doses that are non-toxic to the yeast cells. The pGKB-GFP loaded MNPs combined with enhancer PEI (Fe3O4@PEI + pGKB-GFP + PEI) are directly transferred to non-competent cells. An effective GFP expression was observed by the selection of antibiotic-resistant yeast cells and heterologous gene integration into the P. pastoris genome was provided. This method, which is very simple, effective, and advanced equipment-free compared to traditional methods, uses smaller amounts of DNA and the process can be performed in a shorter time. The suggested method might also be adapted for the transformation of other yeast species.
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Affiliation(s)
- Seyda Yildiz
- Department of Molecular Biology and Genetics, Atatürk University Erzurum 25240 Turkey
| | - Kubra Solak
- Department of Nanoscience and Nanoengineering, Atatürk University Erzurum 25240 Turkey
| | - Melek Acar
- Department of Molecular Biology and Genetics, Atatürk University Erzurum 25240 Turkey
| | - Ahmet Mavi
- Department of Nanoscience and Nanoengineering, Atatürk University Erzurum 25240 Turkey
- Department of Chemistry Education, Kazım Karabekir Faculty of Education, Atatürk University Erzurum 25240 Turkey
| | - Yagmur Unver
- Department of Molecular Biology and Genetics, Atatürk University Erzurum 25240 Turkey
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Zhang X, Wang C, Ge Y, Meng Q, Zhang Y. Constitutive secretory expression and characterization of nitrilase from Alcaligenes faecalis in Pichia pastoris for production of R-mandelic acid. Biotechnol Appl Biochem 2021; 69:587-595. [PMID: 33650215 DOI: 10.1002/bab.2135] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Accepted: 02/14/2021] [Indexed: 11/07/2022]
Abstract
Nitrilases can directly hydrolyze nitrile compounds into carboxylic acids and ammonium. To solve the current problems of bioconversions using nitrilases, including the difficult separation of products from the resting cells used as the catalyst and high costs of chemical inducers, a nitrilase from Alcaligenes faecalis was heterologously expressed in Pichia pastoris X33. The stable nitrilase-expressing strain No.39-6-4 was obtained after three rounds of screening based on a combined detection method including dot-blot, SDS-PAGE, and western blot analyses, which confirmed the presence of recombinant nitrilase with a molecular mass of about 50 kDa. The temperature and pH optima of the nitrilase were 45°C and pH 7.5, respectively. Cu2+ , Zn2+ , and Tween 80 strongly inhibited the enzyme activity, but the optical purity of the product R-mandelic acid (R-MA) was stable, with practically 100% enantiomeric excess (ee). The nitrilase-producing P. pastoris strain developed in this study provides a basis for further research on the enzyme.
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Affiliation(s)
- Xinhong Zhang
- School of Biology, Food and Environment, Hefei University, Hefei, China
| | - Chuyan Wang
- School of Biology, Food and Environment, Hefei University, Hefei, China
| | - Yang Ge
- School of Biology, Food and Environment, Hefei University, Hefei, China
| | - Qingnan Meng
- Institute of Pharmaceutical Biotechnology, University of Science and Technology of China, Hefei, China
| | - Yi Zhang
- School of Biology, Food and Environment, Hefei University, Hefei, China
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Che Z, Cao X, Chen G, Liang Z. An effective combination of codon optimization, gene dosage, and process optimization for high-level production of fibrinolytic enzyme in Komagataella phaffii (Pichia pastoris). BMC Biotechnol 2020; 20:63. [PMID: 33276774 PMCID: PMC7716587 DOI: 10.1186/s12896-020-00654-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 11/05/2020] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND As a main drug for diseased thrombus, some clinically used thrombolytic agents have various disadvantages, safer novel thrombolytic agents are of great demand. This study aimed to achieve high and efficient production of a fibrinolytic enzyme with superior enzymatic properties, by a combination strategy of codon optimization, gene dosage and process optimization in Komagataella phaffii (K. phaffii). RESULTS After codon optimization, the fibase from a marine Bacillus subtilis was expressed and secreted in K. phaffii GS115. Recombinant strains harboring different copies of the fib gene (fib-nc) were successfully obtained via Geneticin (0.25-4 mg/ml) screening on minimal dextrose selection plates and assessment via real-time quantitative PCR. The respective levels of fibase produced by strains expressing fib-5.4c, fib-6c, fib-8c, fib-9c, and fib-12c were 4428, 5781, 7323, 7930, and 2472 U/ml. Levels increased as the copy number increased from 4 to 9, but decreased dramatically at copy number 12. After high cell density fermentation optimization, the highest fibase activity of the strain expressing fib-9c was 7930 U/ml in a shake flask and increased to 12,690 U/ml after 3 days of continuous culture in a 5-L fermenter, which is one of the highest levels of production reported. The recombinant fibase was maximally active at pH 9.0 and 45 °C, and was remarkably stable at pH levels ranging from 5 to 10 and temperatures up to 50 °C. As a metal-dependent serine protease, fibase did not cause hemolysis in vitro and preferentially degraded fibrin directly. CONCLUSIONS The combination of codon optimization, gene dosage, and process optimization described herein could be used for the expression of other therapeutic proteins difficult to express. The characteristics of the recombinant fibase suggest that it has potential applications for thrombosis prevention and therapy.
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Affiliation(s)
- Zhiqun Che
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Microorganism and Enyme Research Center of Engineering Technology, College of Life Science and Technology, Guangxi University, Nanning, 530004, China
| | - Xiaoyan Cao
- College of Agriculture and Forestry Science, Linyi University, Linyi, 276000, China
| | - Guiguang Chen
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Microorganism and Enyme Research Center of Engineering Technology, College of Life Science and Technology, Guangxi University, Nanning, 530004, China
| | - Zhiqun Liang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources, Guangxi Microorganism and Enyme Research Center of Engineering Technology, College of Life Science and Technology, Guangxi University, Nanning, 530004, China.
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