Affordable Access

Protonation state of Asp120 in the binuclear active site of the metallo-beta-lactamase from Bacteroides fragilis.

Authors
Type
Published Article
Journal
Inorganic chemistry
Publication Date
Volume
42
Issue
14
Pages
4245–4247
Identifiers
PMID: 12844290
Source
Medline
License
Unknown

Abstract

The determination of the protonation state of enzyme active sites may be crucial for the investigation of their mechanism of action. In the bizinc beta-lactamase family of enzymes, no consensus has been reached on the protonation state of a fully conserved amino acid present in the active site, Asp120. To address this issue, we carry out here density functional theory (DFT) calculations on large models (based on Bacteroides fragilis X-ray structure) which include the metal coordination polyhedron and groups interacting with it. Our calculations suggest that Asp120 is ionized. The relevance of this finding for site-directed mutagenesis experiments on the 120 position and on the mechanism of action is discussed.

Statistics

Seen <100 times