Biochemical Properties of a Novel Cold-Adapted GH19 Chitinase with Three Chitin-Binding Domains from Chitinilyticum aquatile CSC-1 and Its Potential in Biocontrol of Plant Pathogenic Fungi

作者：Liyan Yang, Mingbo Qu, Zhou Wang, Shiyong Huang, Qingyan Wang, Maochun Wei, Fei Li, Dengfeng Yang, Lixia Pan · 发表于：Journal of Agricultural and Food Chemistry · 年份：2024 · DOI：10.1021/acs.jafc.4c02559 · 被引用次数：11 · 研究领域：Studies on Chitinases and Chitosanases、Legume Nitrogen Fixing Symbiosis、Plant-Microbe Interactions and Immunity

GH19 (glycoside hydrolase 19) chitinases play crucial roles in the enzymatic conversion of chitin and biocontrol of phytopathogenic fungi. Herein, a novel multifunctional chitinase of GH19 ( Ca Chi19A), which contains three chitin-binding domains (ChBDs), was successfully cloned from Chitinilyticum aquatile CSC-1 and heterologously expressed in Escherichia coli . We also generated truncated mutants of Ca Chi19A_ΔI, Ca Chi19A_ΔIΔII, and Ca Chi19A_CatD consisting of two ChBDs and a catalytic domain, one ChBD and a catalytic domain, and only a catalytic domain, respectively. Ca Chi19A, Ca Chi19A_ΔI, Ca Chi19A_ΔIΔII, and Ca Chi19A_CatD exhibited cold adaptation, as their relative enzyme activities at 5 °C were 40.7, 51.6, 66.2, and 82.6%, respectively. Compared with Ca Chi19A and other variants, Ca Chi19A_ΔIΔII demonstrated a higher level of stability below 50 °C and retained relatively high activity over a wide pH range of 5–12. Analysis of the hydrolysis products revealed that Ca Chi19A and Ca Chi19A_ΔIΔII exhibit exoacting, endoacting, and N -acetyl-β- d -glucosaminidase activities toward colloidal chitin. Furthermore, Ca Chi19A and Ca Chi19A_ΔIΔII exhibited inhibitory effects on the hyphal growth of Fusarium oxysporum, Fusarium redolens, Fusarium fujikuroi, Fusarium solani, and Coniothyrium diplodiella, thereby illustrating effective biocontrol activity. These results indicated that Ca Chi19A and Ca Chi19A_ΔIΔII show advantages in some applications where low temperatures were...