Biochemical characterization of the Pseudomonas aeruginosa 101/1477 metallo-beta-lactamase IMP-1 produced by Escherichia coli.
The blaIMP gene coding for the IMP-1 metallo-beta-lactamase produced by a Pseudomonas aeruginosa clinical isolate (isolate 101/1477) was overexpressed via a T7 expression system in Escherichia coli BL21 (DE3), and its product was purified to homogeneity with a final yield of 35 mg/liter of culture. The structural and functional properties of the enzyme purified from E. coli were identical to those of the enzyme produced by P. aeruginosa. The IMP-1 metallo-beta-lactamase exhibits a broad-spectrum activity profile that includes activity against penicillins, cephalosporins, cephamycins, oxacephamycins, and carbapenems. Only monobactams escape its action. The enzyme activity was inhibited by metal chelators, of which 1,10-o-phenanthroline and dipicolinic acid were the most efficient. Two zinc-binding sites were found. The zinc content of the P. aeruginosa 101/1477 metallo-beta-lactamase was not pH dependent.
Laraki
N
N
Laboratoire d'Enzymologie, Institut de Chimie, Université de Liège, Belgium.
Franceschini
N
N
Rossolini
G M
GM
Santucci
P
P
Meunier
C
C
de Pauw
E
E
Amicosante
G
G
Frère
J M
JM
Galleni
M
M
D000900:Anti-Bacterial Agents / Q000378:metabolism; D001426:Bacterial Proteins; D002614:Chelating Agents / Q000494:pharmacology; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010848:Picolinic Acids / Q000494:pharmacology; D011550:Pseudomonas aeruginosa / Q000201:enzymology*; D015032:Zinc / Q000378:metabolism; D065093:beta-Lactamase Inhibitors; D001618:beta-Lactamases / Q000378:metabolism*
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D002614:Chelating Agents; D010848:Picolinic Acids; D065093:beta-Lactamase Inhibitors; D001618:beta-Lactamases; D015032:Zinc; C004860:dipicolinic acid