A Quantum Mechanics / Molecular Mechanics Study of the Protein-Ligand Interaction of two potent inhibitors of human O-GlcNAcase: PUGNAc and NAG-thiazoline

Abstract

O-glycoprotein 2-acetamino-2-deoxy-β-D-glucopyranosidase (O-GlcNAcase) hydrolyzes 2-acetamido-2-deoxy-β-D-glucopyranose (O-GlcNAc) residues of serine/threonine residues of modified proteins. O-GlcNAc is present in many intracellular proteins and appears to have a role in the etiology of several diseases including cancer, Alzheimer’s disease, and type II diabetes. In this work, we have carried out molecular dynamics (MD) simulations using a hybrid Quantum Mechanics / Molecular Mechanics (QM/MM) approach, to determine the binding of two potent inhibitors, PUGNAc and NAG, with a bacterial O-GlcNAcase. The results of these simulations show that Asp-401, Asp-298 and Asp-297 residues play an important role in the protein-inhibitor interactions. These results might be useful to design compounds with more interesting inhibitory activity on the basis of its three-dimensional structure