Elucidation of the mechanism underlying the sequential catalysis of inulin by fructotransferase.

Autor: Chen G; State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China; College of Food and Health, Zhejiang Agriculture and Forest University, Hangzhou 311300, China., Wang ZX; Key Laboratory of Innate Immune Biology of Fujian Province, Provincial University Key Laboratory of Cellular Stress Response and Metabolic Regulation, Biomedical Research Center of South China, Key Laboratory of OptoElectronic Science and Technology for Medicine of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou 350117, China., Yang Y; State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China., Li Y; State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China., Zhang T; State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China., Ouyang S; Key Laboratory of Innate Immune Biology of Fujian Province, Provincial University Key Laboratory of Cellular Stress Response and Metabolic Regulation, Biomedical Research Center of South China, Key Laboratory of OptoElectronic Science and Technology for Medicine of Ministry of Education, College of Life Sciences, Fujian Normal University, Fuzhou 350117, China., Zhang L; Hefei National Laboratory for Physical Science at the Microscale, University of Science and Technology of China, Hefei 230027, China. Electronic address: zhangl99@ustc.edu.cn., Chen Y; CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China. Electronic address: chenyang2808@dicp.ac.cn., Ruan X; Department of Neurology, Fujian Medical University Union Hospital, 29 Xinquan Road Gulou District, Fuzhou 350001, China. Electronic address: xlruan@163.com., Miao M; State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China. Electronic address: miaoming@jiangnan.edu.cn.
Jazyk: angličtina
Zdroj: International journal of biological macromolecules [Int J Biol Macromol] 2024 Oct; Vol. 277 (Pt 3), pp. 134446. Date of Electronic Publication: 2024 Aug 03.
DOI: 10.1016/j.ijbiomac.2024.134446
Abstrakt: Glycoside hydrolase family 91 (GH91) inulin fructotransferase (IFTases) enables biotransformation of fructans into sugar substitutes for dietary intervention in metabolic syndrome. However, the catalytic mechanism underlying the sequential biodegradation of inulin remains unelusive during the biotranformation of fructans. Herein we present the crystal structures of IFTase from Arthrobacter aurescens SK 8.001 in apo form and in complexes with kestose, nystose, or fructosyl nystose, respectively. Two kinds of conserved noncatalytic binding regions are first identified for IFTase-inulin interactions. The conserved interactions of substrates were revealed in the catalytic center that only contained a catalytic residue E205. A switching scaffold was comprised of D194 and Q217 in the catalytic channel, which served as the catalytic transition stabilizer through side chain displacement in the cycling of substrate sliding in/out the catalytic pocket. Such features in GH91 contribute to the catalytic model for consecutive cutting of substrate chain as well as product release in IFTase, and thus might be extended to other exo-active enzymes with an enclosed bottom of catalytic pocket. The study expands the current general catalytic principle in enzyme-substrate complexes and shed light on the rational design of IFTase for fructan biotransformation.
Competing Interests: Declaration of competing interest There is no conflict of interests regarding the publication of this article.
(Copyright © 2024 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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