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Biochemical and Structural Characterization of the Subclass B1 Metallo-β-Lactamase VIM-4 ▿

By Patricia Lassaux, Daouda A. K. Traoré, Elodie Loisel, Adrien Favier, Jean-Denis Docquier, Jean Sébastien Sohier, Clémentine Laurent, Carine Bebrone, Jean-Marie Frère, Jean-Luc Ferrer and Moreno Galleni

Abstract

The metallo-β-lactamase VIM-4, mainly found in Pseudomonas aeruginosa or Acinetobacter baumannii, was produced in Escherichia coli and characterized by biochemical and X-ray techniques. A detailed kinetic study performed in the presence of Zn2+ at concentrations ranging from 0.4 to 100 μM showed that VIM-4 exhibits a kinetic profile similar to the profiles of VIM-2 and VIM-1. However, VIM-4 is more active than VIM-1 against benzylpenicillin, cephalothin, nitrocefin, and imipenem and is less active than VIM-2 against ampicillin and meropenem. The crystal structure of the dizinc form of VIM-4 was solved at 1.9 Å. The sole difference between VIM-4 and VIM-1 is found at residue 228, which is Ser in VIM-1 and Arg in VIM-4. This substitution has a major impact on the VIM-4 catalytic efficiency compared to that of VIM-1. In contrast, the differences between VIM-2 and VIM-4 seem to be due to a different position of the flapping loop and two substitutions in loop 2. Study of the thermal stability and the activity of the holo- and apo-VIM-4 enzymes revealed that Zn2+ ions have a pronounced stabilizing effect on the enzyme and are necessary for preserving the structure

Topics: Mechanisms of Resistance
Publisher: American Society for Microbiology (ASM)
OAI identifier: oai:pubmedcentral.nih.gov:3067066
Provided by: PubMed Central
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