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Zhou Y, Ke F, Chen L, Lu Y, Zhu L, Chen X. Enhancing regioselectivity of sucrose phosphorylase by loop engineering for glycosylation of L-ascorbic acid. Appl Microbiol Biotechnol 2022; 106:4575-4586. [PMID: 35739344 DOI: 10.1007/s00253-022-12030-w] [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: 05/04/2022] [Revised: 06/09/2022] [Accepted: 06/10/2022] [Indexed: 11/26/2022]
Abstract
Sucrose phosphorylase (SPase) has a remarkable capacity to synthesize numerous glucosides from abundantly available sucrose under mild conditions but suffers from specificity and regioselectivity issues. In this study, a loop engineering strategy was introduced to enhance the regioselectivity and substrate specificity of SPase for the efficient synthesis of 2-O-α-D-glucopyranosyl-L-ascorbic acid (AA-2G) via L-ascorbic acid (L-AA). P134, L341, and L343 were identified as "hotspots" for modulating the flexibility of loops, which significantly influenced the H-bonding network of L-AA in the active site, as well as the entrance of the substrate channel, thereby altering the regioselectivity and substrate specificity. Finally, the mutant L341V/L343F, with near-perfect control of the selectivity synthesis of the 2-OH group of L-AA (> 99%), was obtained. The AA-2G production by the mutant reached 244 g L-1 in a whole-cell biotransformation system, and the conversion rate of L-AA reached 64%, which is the highest level reported to date. Our work also provides a successful loop engineering case for modulating the regioselectivity and specificity of sucrose phosphorylase. KEY POINTS: • "Hotspots" were identified in the flexible loops of sucrose phosphorylase. • Mutants exhibited improved regioselectivity and specificity against L-ascorbic acid. • Synthesized AA-2G with high yield and regioselectivity by whole-cell of mutant.
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Affiliation(s)
- Yaoyao Zhou
- Institute of Fermentation Engineering, Zhejiang University of Technology, Hangzhou, 310014, China
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, 310014, China
| | - Feifei Ke
- Institute of Fermentation Engineering, Zhejiang University of Technology, Hangzhou, 310014, China
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, 310014, China
| | - Luyi Chen
- Institute of Fermentation Engineering, Zhejiang University of Technology, Hangzhou, 310014, China
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, 310014, China
| | - Yuele Lu
- Institute of Fermentation Engineering, Zhejiang University of Technology, Hangzhou, 310014, China
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, 310014, China
| | - Linjiang Zhu
- Institute of Fermentation Engineering, Zhejiang University of Technology, Hangzhou, 310014, China.
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, 310014, China.
| | - Xiaolong Chen
- Institute of Fermentation Engineering, Zhejiang University of Technology, Hangzhou, 310014, China
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou, 310014, China
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Zhang Y, Breum NMD, Schubert S, Hashemi N, Kyhnau R, Knauf MS, Mathialakan M, Takeuchi M, Kishino S, Ogawa J, Kristensen P, Guo Z, Eser BE. Semi-rational Engineering of a Promiscuous Fatty Acid Hydratase for Alteration of Regioselectivity. Chembiochem 2021; 23:e202100606. [PMID: 34929055 DOI: 10.1002/cbic.202100606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 12/14/2021] [Indexed: 11/12/2022]
Abstract
Fatty acid hydratases (FAHs) catalyze regio- and stereo-selective hydration of unsaturated fatty acids to produce hydroxy fatty acids. Fatty acid hydratase-1 (FA-HY1) from Lactobacillus Acidophilus is the most promiscuous and regiodiverse FAH identified so far. Here, we engineered binding site residues of FA-HY1 (S393, S395, S218 and P380) by semi-rational protein engineering to alter regioselectivity. Although it was not possible to obtain a completely new type of regioselectivity with our mutant libraries, a significant shift of regioselectivity was observed towards cis-5, cis-8, cis-11, cis-14, cis-17-eicosapentaenoic acid (EPA). We identified mutants (S393/S395 mutants) with excellent regioselectivity, generating a single hydroxy fatty acid product from EPA (15-OH product), which is advantageous from application perspective. This result is impressive given that wild-type FA-HY1 produces a mixture of 12-OH and 15-OH products at 63 : 37 ratio (12-OH : 15-OH). Moreover, our results indicate that native FA-HY1 is at its limit in terms of promiscuity and regiospecificity, thus it may not be possible to diversify its product portfolio with active site engineering. This behavior of FA-HY1 is unlike its orthologue, fatty acid hydratase-2 (FA-HY2; 58 % sequence identity to FA-HY1), which has been shown earlier to exhibit significant promiscuity and regioselectivity changes by a few active site mutations. Our reverse engineering from FA-HY1 to FA-HY2 further demonstrates this conclusion.
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Affiliation(s)
- Yan Zhang
- Department of Biological and Chemical Engineering, Aarhus University, 8000, Aarhus, Denmark
| | | | - Sune Schubert
- Department of Biological and Chemical Engineering, Aarhus University, 8000, Aarhus, Denmark
| | - Negin Hashemi
- Department of Biological and Chemical Engineering, Aarhus University, 8000, Aarhus, Denmark
| | - Rikke Kyhnau
- Department of Biological and Chemical Engineering, Aarhus University, 8000, Aarhus, Denmark
| | - Marius Sandholt Knauf
- Department of Biological and Chemical Engineering, Aarhus University, 8000, Aarhus, Denmark
| | - Masuthan Mathialakan
- Department of Biological and Chemical Engineering, Aarhus University, 8000, Aarhus, Denmark
| | - Michiki Takeuchi
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, 606-8502, Japan
| | - Shigenobu Kishino
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, 606-8502, Japan
| | - Jun Ogawa
- Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, 606-8502, Japan
| | - Peter Kristensen
- Faculty of Engineering and Science, Department of Chemistry and Bioscience, Aalborg University, 9220, Aalborg, Denmark
| | - Zheng Guo
- Department of Biological and Chemical Engineering, Aarhus University, 8000, Aarhus, Denmark
| | - Bekir Engin Eser
- Department of Biological and Chemical Engineering, Aarhus University, 8000, Aarhus, Denmark
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