QM/MM Simulations of Enzymatic Hydrolysis of Cellulose: Probing the Viability of an Endocyclic Mechanism for an Inverting Cellulase.

ABSTRACT: Glycoside hydrolases (GH) cleave carbohydrate glycosidic bonds and play pivotal roles in living organisms and in many industrial processes. Unlike acid-catalyzed hydrolysis of carbohydrates in solution, which can occur either via cyclic or acyclic oxocarbenium-like transition states, it is widely accepted that GH-catalyzed hydrolysis proceeds via a general acid mechanism involving a cyclic oxocarbenium-like transition state with protonation of the glycosidic oxygen. The GH45 subfamily C inverting endoglucanase from Phanerochaete chrysosporium (PcCel45A) defies the classical inverting mechanism as its crystal structure conspicuously lacks a general Asp or Glu base residue. Instead, PcCel45A has an Asn residue, a notoriously weak base in solution, as one of its catalytic residues at p

SUBMITTER: Pereira CS 

PROVIDER: S-EPMC8154253 | biostudies-literature | 2021 Apr

REPOSITORIES: biostudies-literature