Study on the functional transformation mechanism of inulin glycosyltransferase and diglycan hydrolase

ACS catalysis, a famous journal of the American Chemical Society, published on-line the cooperative paper "structural and functional basis of difrutose anhydride III hydrolase, which" by Professor Teng MaiKun / Associate Professor Li Xu of the Department of life science and medicine of University of science and technology of China and Hefei National Research Center of microscale material science and Professor mu wanmeng of Jiangnan University Sequential conversions inulin using the same catalytic residue ", a bifunctional enzyme dfa-iiase with continuous catalytic activity for inulin was discovered for the first time in this study, and its bifunctional conversion mechanism was revealed The discovery of this mechanism provides a new idea for the design of continuous catalytic transformation of the enzyme Inulin is a kind of natural fructan mixture Its decomposition product, dfa-iii, has an important physiological regulation function, and has important effects in promoting the growth and reproduction of intestinal probiotics, promoting the absorption of trace elements, anti caries, diuresis, improving constipation, etc Dfa-iii can be further decomposed into inulin disaccharide under the catalysis of dfa-iiase, but its catalytic mechanism is not clear In this study, a dfa-iiase with the functions of both inulin glycotransferase and diglycan hydrolase was isolated from Arthrobacter chlorophenol by the cooperative research group of the University of science and technology of China and Jiangnan University for the first time The molecular mechanism of the enzyme to continuously catalyze inulin substrate through a cover with variable configuration was elucidated through 11 different crystal structures of monomers and complexes 。 This work, on the one hand, elucidates the molecular mechanism of dfa-iii hydrolysis by dimercarboxylic anhydride hydrolase at the atomic level, on the other hand, provides an interesting example of continuous enzyme catalysis, which provides a new perspective for the design and research of multi-functional continuous catalytic modification of other enzymes The research work was supported by NSFC The corresponding authors are Li Xu, associate professor of University of science and technology of China and mu wanmeng, Professor of Jiangnan University The first authors are Yu Shuhuai, classmate of Jiangnan University and Shen Hui, doctor of University of science and technology of China.