Three factors that modulate the activity of class D β-lactamases and interfere with the post-translational carboxylation of Lys70.

TitleThree factors that modulate the activity of class D β-lactamases and interfere with the post-translational carboxylation of Lys70.
Publication TypeJournal Article
Year of Publication2010
AuthorsVercheval, L., C. Bauvois, A. di Paolo, F. Borel, J-L. Ferrer, E. Sauvage, A. Matagne, J-M. Frère, P. Charlier, M. Galleni, and F. Kerff
JournalBiochem J
Volume432
Issue3
Pagination495-504
Date Published2010 Dec 15
ISSN1470-8728
KeywordsAcylation, Amino Acid Sequence, Amino Acid Substitution, Anti-Bacterial Agents, Bacterial Proteins, beta-Lactamases, Catalytic Domain, Chlorides, Conserved Sequence, Crystallography, X-Ray, Enzyme Inhibitors, Hydrophobic and Hydrophilic Interactions, Kinetics, Lysine, Moxalactam, Mutant Proteins, Osmolar Concentration, Protein Binding, Protein Conformation, Protein Processing, Post-Translational, Pseudomonas aeruginosa, Recombinant Proteins
Abstract

The activity of class D β-lactamases is dependent on Lys70 carboxylation in the active site. Structural, kinetic and affinity studies show that this post-translational modification can be affected by the presence of a poor substrate such as moxalactam but also by the V117T substitution. Val117 is a strictly conserved hydrophobic residue located in the active site. In addition, inhibition of class D β-lactamases by chloride ions is due to a competition between the side chain carboxylate of the modified Lys70 and chloride ions. Determination of the individual kinetic constants shows that the deacylation of the acyl-enzyme is the rate-limiting step for the wild-type OXA-10 β-lactamase.
DOI10.1042/BJ20101122
Alternate JournalBiochem. J.
PubMed ID21108605