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Publication Abstract from PubMed

The metallo-beta-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 Zn(2+) concentration ranging from 0.4 to 100 muM showed that VIM-4 exhibits a kinetic profile similar to those of VIM-2 and VIM-1. However, VIM-4 is more active than VIM-1 against benzylpenicillin, cephalothin, nitrocefin and imipenem and less active than VIM-2 against ampicillin and meropenem. The crystal structure of the di-zinc form of VIM-4 was solved at 1.9 A. 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 when compared to VIM-1. By contrast, the differences between VIM-2 and VIM-4 seem 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 Zn(2+) ions have a pronounced stabilizing effect on the enzyme and are necessary for preserving the structure.

Biochemical and Structural Characterization of the Subclass B1 Metallo-{beta}-Lactamase VIM-4.,Lassaux P, Traore DA, Loisel E, Favier A, Docquier JD, Sohier JS, Laurent C, Bebrone C, Frere JM, Ferrer JL, Galleni M Antimicrob Agents Chemother. 2010 Dec 13. PMID:21149620^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.