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+) at concentrations ranging from 0.4 to 100 mu M 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 angstrom. 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 Zn(2+) ions have a pronounced stabilizing effect on the enzyme and are necessary for preserving the structure.

Lassaux, P., Traoré, D.a., Loisel, E., Favier, A., Docquier, J.D., Sohier, J.s., et al. (2011). Biochemical and structural characterization of the subclass B1 metallo-β-lactamase VIM-4. ANTIMICROBIAL AGENTS AND CHEMOTHERAPY, 55(3), 1248-1255 [10.1128/AAC.01486-09].

Biochemical and structural characterization of the subclass B1 metallo-β-lactamase VIM-4.

DOCQUIER, JEAN DENIS;
2011

Abstract

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+) at concentrations ranging from 0.4 to 100 mu M 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 angstrom. 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 Zn(2+) ions have a pronounced stabilizing effect on the enzyme and are necessary for preserving the structure.
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11365/20973
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