A transglycosylating chitinase from Chitiniphilus shinanonensis (CsChiL) hydrolyzes chitin in a processive manner

摘要

Chitin, mostly extracted from shrimp waste, is the second most abundant biopolysaccharide, next only to cellulose. Enzymatic conversion of chitin into useful bioactive molecules such as chitooligosaccharides (COS) has potential biotechnological applications. The current study describes the characterization of a single modular GH18 chitinase from Chitiniphilus shinanonensis (CsChiL). CsChiL was optimally active at 50 degrees C in sodium citrate buffer, pH 6.0 and active over a broad pH range (6-10). In addition to hydrolysis, CsChiL displayed chitobiase and transglycosylation activities on COS with degree of polymerization (DP) 2 and 4-6, respectively. CsChiL hydrolyzed chitin polymers (alpha, beta, and colloidal chitin) in a processive manner. Molecular dynamics simulations and residue-wise binding energy contributions provided structural insights and molecular basis of inherent transglycosylation activity by CsChiL. Overall, CsChiL could be useful in generation of COS from the chitin obtained from shrimp waste with potential applications in agriculture and food industries. (C) 2019 Elsevier B.V. All rights reserved.