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Wang L, Jiang Z, Zhang J, Chen K, Zhang M, Wang Z, Wang B, Ye M, Qiao X. Characterization and structure-based protein engineering of a regiospecific saponin acetyltransferase from Astragalus membranaceus. Nat Commun 2023; 14:5969. [PMID: 37749089 PMCID: PMC10519980 DOI: 10.1038/s41467-023-41599-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Accepted: 09/12/2023] [Indexed: 09/27/2023] Open
Abstract
Acetylation contributes to the bioactivity of numerous medicinally important natural products. However, little is known about the acetylation on sugar moieties. Here we report a saponin acetyltransferase from Astragalus membranaceus. AmAT7-3 is discovered through a stepwise gene mining approach and characterized as the xylose C3'/C4'-O-acetyltransferse of astragaloside IV (1). To elucidate its catalytic mechanism, complex crystal structures of AmAT7-3/1 and AmAT7-3A310G/1 are obtained, which reveal a large active pocket decided by a specific sequence AADAG. Combining with QM/MM computation, the regiospecificity of AmAT7-3 is determined by sugar positioning modulated by surrounding amino acids including #A310 and #L290. Furthermore, a small mutant library is built using semi-rational design, where variants A310G and A310W are found to catalyze specific C3'-O and C4'-O acetylation, respectively. AmAT7-3 and its variants are also employed to acetylate other bioactive saponins. This work expands the understanding of saponin acetyltransferases, and provide efficient catalytic tools for saponin acetylation.
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Affiliation(s)
- Linlin Wang
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing, 100191, China
| | - Zhihui Jiang
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, 361005, Xiamen, China
| | - Jiahe Zhang
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing, 100191, China
| | - Kuan Chen
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing, 100191, China
| | - Meng Zhang
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing, 100191, China
| | - Zilong Wang
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing, 100191, China
| | - Binju Wang
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, 361005, Xiamen, China.
| | - Min Ye
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing, 100191, China.
- Peking University-Yunnan Baiyao International Medical Research Center, 38 Xueyuan Road, Beijing, 100191, China.
| | - Xue Qiao
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing, 100191, China.
- Peking University-Yunnan Baiyao International Medical Research Center, 38 Xueyuan Road, Beijing, 100191, China.
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Mondal S, Tseng CJ, Tan JJY, Lin DY, Lin HY, Weng JH, Lin CH, Mong KKT. Tunable Strategy for the Asymmetric Synthesis of Sulfoglycolipids from Mycobacterium tuberculosis To Elucidate the Structure and Immunomodulatory Property Relationships. Angew Chem Int Ed Engl 2023; 62:e202212514. [PMID: 36349422 DOI: 10.1002/anie.202212514] [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: 08/24/2022] [Indexed: 11/11/2022]
Abstract
We developed a versatile asymmetric strategy to synthesize different classes of sulfoglycolipids (SGLs) from Mycobacterium tuberculosis. The strategy features the use of asymmetrically protected trehaloses, which were acquired from the glycosylation of TMS α-glucosyl acceptors with benzylidene-protected thioglucosyl donors. The positions of the protecting groups at the donors and acceptors can be fine-tuned to obtain different protecting-group patterns, which is crucial for regioselective acylation and sulfation. In addition, a chemoenzymatic strategy was established to prepare the polymethylated fatty acid building blocks. The strategy employs inexpensive lipase as a desymmetrization agent in the preparation of the starting substrate and readily available chiral oxazolidinone as a chirality-controlling agent in the construction of the polymethylated fatty acids. A subsequent investigation on the immunomodulatory properties of each class of SGLs showed how the structures of SGLs impact the host innate immunity response.
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Affiliation(s)
- Soumik Mondal
- Applied Chemistry Department, National Yang Ming Chiao Tung University (Previously National Chiao Tung University), 1001, University Road, Hsinchu City, Taiwan, R. O. C
| | - Chieh-Jen Tseng
- Applied Chemistry Department, National Yang Ming Chiao Tung University (Previously National Chiao Tung University), 1001, University Road, Hsinchu City, Taiwan, R. O. C
| | - Janet Jia-Yin Tan
- Institute of Biological Chemistry, Academia Sinica, No.128, Academia Road Section2, Nan-Kang, Taipei, 11529, Taiwan
| | - Ding-Yuan Lin
- Applied Chemistry Department, National Yang Ming Chiao Tung University (Previously National Chiao Tung University), 1001, University Road, Hsinchu City, Taiwan, R. O. C
| | - Hsien-Ya Lin
- Institute of Biological Chemistry, Academia Sinica, No.128, Academia Road Section2, Nan-Kang, Taipei, 11529, Taiwan
| | - Jui-Hsia Weng
- Institute of Biological Chemistry, Academia Sinica, No.128, Academia Road Section2, Nan-Kang, Taipei, 11529, Taiwan
| | - Chun-Hung Lin
- Institute of Biological Chemistry, Academia Sinica, No.128, Academia Road Section2, Nan-Kang, Taipei, 11529, Taiwan.,Graduate Institute of Biotechnology and Biotechnology Center, National Chung-Hsing University, Taichung, 40227, Taiwan.,Department of Chemistry and Institute of Biochemical Sciences, National Taiwan University, Taipei, 10617, Taiwan
| | - Kwok-Kong Tony Mong
- Applied Chemistry Department, National Yang Ming Chiao Tung University (Previously National Chiao Tung University), 1001, University Road, Hsinchu City, Taiwan, R. O. C
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Weldu WD, Wang CC. Rationalizing the Stereoelectronic Influence of Interglycosidic Bond Conformations on the Reactivity of 1,4- O-Linked Disaccharide Donors. J Org Chem 2021; 86:17906-17917. [PMID: 34818891 DOI: 10.1021/acs.joc.1c02207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Disaccharide donors are key precursors in convergent glycan synthesis strategies. Unexpectedly, we observed that disaccharide thioglycosyl donors containing 1,4-O-linked α-glycosidic bonds are much more reactive than their β-analogues with the same protecting group pattern. Herein, we rationalized that such a difference in their reactivity is attributed to the conformation of the 1,4-O-interglycosidic bond which is controlled by anomeric and exo-anomeric effects. Moreover, the conformational preferences of these donors are dictated by the dihedral angles ϕ and ψ of their interglycosidic linkages and the torsional angle ω of their side chain along the C5-C6 bond. This fundamental research clarifies how the long-range stereoelectronic effects from the nonreducing end sugar can influence the reactivity of the leaving group at the reducing end and the behavior of disaccharide donors thereof.
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Affiliation(s)
- Welday Desta Weldu
- Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan.,Sustainable Chemical Science and Technology (SCST), Taiwan International Graduate Program (TIGP), Academia Sinica, Taipei 115, Taiwan.,Department of Applied Chemistry, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan
| | - Cheng-Chung Wang
- Institute of Chemistry, Academia Sinica, Taipei 115, Taiwan.,Sustainable Chemical Science and Technology (SCST), Taiwan International Graduate Program (TIGP), Academia Sinica, Taipei 115, Taiwan
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Zhang T, Yang Z, Zhou D, Meng F, Han Z, Huang H. Non-metal Lewis acid-catalyzed cross-Claisen condensation for β-keto esters. Org Biomol Chem 2021; 19:9163-9166. [PMID: 34642729 DOI: 10.1039/d1ob01785c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this work, we disclose a new catalytic and highly chemoselective cross-Claisen condensation of esters. In the presence of TBSNTf2 as a non-metal Lewis acid, various esters can undergo cross-Claisen condensation to form β-keto esters which are important building blocks. Compared with the traditional Claisen condensation, this process, employing silyl ketene acetals (SKAs) as carbonic nucleophiles to achieve cross-Claisen condensation, requires mild conditions and has good tolerance of functional groups.
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Affiliation(s)
- Tianyu Zhang
- Jiangsu Key Laboratory of Advanced Catalytic Materials & Technology, School of Petrochemical Engineering, Changzhou University, Changzhou, China.
| | - Zhenkun Yang
- Jiangsu Key Laboratory of Advanced Catalytic Materials & Technology, School of Petrochemical Engineering, Changzhou University, Changzhou, China.
| | - Dapeng Zhou
- Hangmo New Materials Group Co., Ltd, Anji, China.
| | - Fuliang Meng
- Hangmo New Materials Group Co., Ltd, Anji, China.
| | - Zhengyu Han
- Jiangsu Key Laboratory of Advanced Catalytic Materials & Technology, School of Petrochemical Engineering, Changzhou University, Changzhou, China.
| | - Hai Huang
- Jiangsu Key Laboratory of Advanced Catalytic Materials & Technology, School of Petrochemical Engineering, Changzhou University, Changzhou, China. .,Hangmo New Materials Group Co., Ltd, Anji, China.
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