title: Biochemical and structural characterization of the subclass B1 metallo-β-lactamase VIM-4.
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.
authors.affiliation: Laboratoire de Macromolecules Biologiques, Centre d'Ingénierie des Protéines, Université de Liège, Allée du 6 Août B6, Sart-Tilman, 4000 Liège, Belgium.
authors.forename: Patricia
authors.initials: P
authors.lastname: Lassaux
authors.forename: Daouda A K
authors.initials: DA
authors.lastname: Traoré
authors.forename: Elodie
authors.initials: E
authors.lastname: Loisel
authors.forename: Adrien
authors.initials: A
authors.lastname: Favier
authors.forename: Jean-Denis
authors.initials: JD
authors.lastname: Docquier
authors.forename: Jean Sébastien
authors.initials: JS
authors.lastname: Sohier
authors.forename: Clémentine
authors.initials: C
authors.lastname: Laurent
authors.forename: Carine
authors.initials: C
authors.lastname: Bebrone
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Frère
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Ferrer
authors.forename: Moreno
authors.initials: M
authors.lastname: Galleni
mesh_terms: D000667:Ampicillin / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000378:metabolism*; D002511:Cephalosporins / Q000378:metabolism; D002512:Cephalothin / Q000378:metabolism; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015378:Imipenem / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D000077731:Meropenem; D010400:Penicillin G / Q000378:metabolism; D013845:Thienamycins; D001618:beta-Lactamases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D002511:Cephalosporins; D013845:Thienamycins; D015378:Imipenem; D000667:Ampicillin; D001618:beta-Lactamases; C021720:nitrocefin; D000077731:Meropenem; D010400:Penicillin G; D002512:Cephalothin