几丁质酶
嗜热菌
甲壳素
活动站点
化学
生物化学
酶
催化作用
蛋白质工程
突变体
合理设计
生物转化
基质(水族馆)
酶催化
立体化学
生物物理学
生物
基因
遗传学
壳聚糖
生态学
作者
Sha Zhang,Mengyu Liu,Xiaomeng Sun,Xukai Jiang,Yingjie Li,Lushan Wang,Lushan Wang
标识
DOI:10.1021/acs.biomac.3c00936
摘要
Chitinase plays a vital role in the efficient biotransformation of the chitin substrate. This study aimed to modify and elucidate the contribution of the relatively conserved residues in the active site architecture of a thermophilic chitinase SsChi18A from Streptomyces sp. F-3 in processive catalysis. The enzymatic activity on colloidal chitin increased to 151%, 135%, and 129% in variants Y286W, E287A, and K186A compared with the wild type (WT). Also, the apparent processive parameter G2/G1 was lower in the variants compared to the WT, indicating the essential role of Tyr-286, Glu-287, and Lys-186 in processive catalysis. Additionally, the enzymatic activity on the crystalline chitin of F48W and double mutants F48W/Y209F and F48W/Y286W increased by 35%, 16%, and 36% compared with that for WT. Molecular dynamics simulations revealed that the driving force of processive catalysis might be related to the changes in interaction energy. This study provided a rational design strategy targeting relatively conserved residues to enhance the catalytic activity of GH18 processive chitinases.
科研通智能强力驱动
Strongly Powered by AbleSci AI