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Yang P, Wang X, Ye J, Rao S, Zhou J, Du G, Liu S. Enhanced Thermostability and Catalytic Activity of Streptomyces mobaraenesis Transglutaminase by Rationally Engineering Its Flexible Regions. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:6366-6375. [PMID: 37039372 DOI: 10.1021/acs.jafc.3c00260] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Streptomyces mobaraenesis transglutaminase can catalyze the cross-linking of proteins, which has been widely used in food processing. In this study, we rationally modified flexible regions to further improve the thermostability of FRAPD-TGm2 (S2P-S23V-Y24N-E28T-S199A-A265P-A287P-K294L), a stable mutant of the transglutaminase constructed in our previous study. First, five flexible regions of FRAPD-TGm2 were identified by molecular dynamics simulations at 330 and 360 K. Second, a script based on Rosetta Cartesian_ddg was developed for virtual saturation mutagenesis within the flexible regions far from the substrate binding pocket, generating the top 18 mutants with remarkable decreases in folding free energy. Third, from the top 18 mutants, we identified two mutants (S116A and S179L) with increased thermostability and activity. Finally, the above favorable mutations were combined to obtain FRAPD-TGm2-S116A-S179L (FRAPD-TGm2A), exhibiting a half-life of 132.38 min at 60 °C (t1/2(60 °C)) and a specific activity of 79.15 U/mg, 84 and 21% higher than those of FRAPD-TGm2, respectively. Therefore, the current result may benefit the application of S. mobaraenesis transglutaminase at high temperatures.
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Affiliation(s)
- Penghui Yang
- Engineering Research Center of Ministry of Education on Food Synthetic Biorheology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Xinglong Wang
- Engineering Research Center of Ministry of Education on Food Synthetic Biorheology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Jiacai Ye
- Engineering Research Center of Ministry of Education on Food Synthetic Biorheology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Shengqi Rao
- College of Food Science and Engineering, Yangzhou University, Yangzhou, Jiangsu 214122, China
| | - Jingwen Zhou
- Engineering Research Center of Ministry of Education on Food Synthetic Biorheology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Guocheng Du
- Engineering Research Center of Ministry of Education on Food Synthetic Biorheology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- The Key Laboratory of Carbohydrate Chemistry and Biotechnology, Ministry of Education, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Song Liu
- Engineering Research Center of Ministry of Education on Food Synthetic Biorheology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Science Center for Future Foods, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Jiangsu Province Engineering Research Center of Food Synthetic Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
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Wang X, Du J, Zhao B, Wang H, Rao S, Du G, Zhou J, Chen J, Liu S. Significantly Improving the Thermostability and Catalytic Efficiency of Streptomyces mobaraenesis Transglutaminase through Combined Rational Design. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:15268-15278. [PMID: 34874715 DOI: 10.1021/acs.jafc.1c05256] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Streptomyces mobaraenesis transglutaminase has been widely used in food processing. We here significantly improved the catalytic properties of S2P-S23V-Y24N-S199A-K294L (TGm1), a highly stabilized variant of the transglutaminase. First, a virtual proline scan was performed based on folding free energy changes to obtain TGm1 variants with enhanced thermostability. Second, the residues within 15 Å of Cys64 in the enzyme-substrate complex of TGm1 were subjected to virtual saturation mutagenesis to generate the variants with reduced binding free energy and increased activity. After combining the favorable mutations, we obtained the variant FRAPD-TGm1-E28T-A265P-A287P (FRAPD-TGm2), exhibiting 66.9 min of half-life at 60 °C (t1/2(60 °C)), 67.8 °C of melting temperature (Tm), and 71.8 U/mg of specific activity, which are 2-fold, 2.6 °C, and 43.8% higher than those of FRAPD-TGm1, respectively. At last, to increase the surface negative net charge of FRAPD-TGm2, we introduced the mutations N96E-S144E-N163D-R183E-R208E-K325E, yielding FRAPD-TGm3. The latter's t1/2(60 °C), Tm, and specific activity were 122.9 min, 68.6 °C, and 83.7 U/mg, which are 83.8%, 0.8 °C, and 16.6% higher than the former, respectively. FRAPD-TGm3 is thus a robust candidate for transglutaminase application.
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Affiliation(s)
- Xinglong Wang
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi 214122, China
- Science Center for Future Foods, Jiangnan University, Wuxi 214122, China
- School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
| | - Jianhui Du
- School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
| | - Beichen Zhao
- School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
| | - Haiyan Wang
- School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
| | - Shengqi Rao
- College of Food Science and Engineering, Yangzhou University, Yangzhou, Jiangsu 214122, China
| | - Guocheng Du
- College of Food Science and Engineering, Yangzhou University, Yangzhou, Jiangsu 214122, China
| | - Jingwen Zhou
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi 214122, China
- Science Center for Future Foods, Jiangnan University, Wuxi 214122, China
- Jiangsu Provisional Research Center for Bioactive Product Processing Technology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
| | - Jian Chen
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi 214122, China
- Science Center for Future Foods, Jiangnan University, Wuxi 214122, China
- School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi 214122, China
| | - Song Liu
- National Engineering Laboratory for Cereal Fermentation Technology, Jiangnan University, Wuxi 214122, China
- Science Center for Future Foods, Jiangnan University, Wuxi 214122, China
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Influence of Microbial Transglutaminase on Physicochemical and Cross-Linking Characteristics of Individual Caseins. Molecules 2020; 25:molecules25173992. [PMID: 32887242 PMCID: PMC7504769 DOI: 10.3390/molecules25173992] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 08/30/2020] [Accepted: 08/31/2020] [Indexed: 11/16/2022] Open
Abstract
The effects of microbial transglutaminase (MTGase) cross-linking on the physicochemical characteristics of individual caseins were investigated. MTGase was used to modify three major individual caseins, namely, κ-casein (κ-CN), αS-casein (αS-CN) and β-casein (β-CN). The SDS-PAGE analysis revealed that MTGase-induced cross-linking occurred during the reaction and that some components with high molecular weights (>130 kDa) were formed from the individual proteins κ-CN, αS-CN and β-CN. Scanning electron microscopy (SEM) and particle size analysis respectively demonstrated that the κ-CN, αS-CN and β-CN particle diameters and protein microstructures were larger and polymerized after MTGase cross-linking. The polymerized κ-CN (~749.9 nm) was smaller than that of β-CN (~7909.3 nm) and αS-CN (~7909.3 nm). The enzyme kinetics results showed KM values of 3.04 × 10−6, 2.37 × 10−4 and 8.90 × 10−3 M for κ-CN, αS-CN and β-CN, respectively, and, furthermore, kcat values of 5.17 × 10−4, 1.92 × 10−3 and 4.76 × 10−2 1/s, for κ-CN, αS-CN and β-CN, respectively. Our results revealed that the cross-linking of β-CN catalyzed by MTGase was faster than that of αS-CN or κ-CN. Overall, the polymers that formed in the individual caseins in the presence of MTGase presented a higher molecular weight and larger particles.
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