The bla(IMP) gene coding for the IMP-1 metallo-β-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-β-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-β-lactamase was not pH dependent.

Biochemical characterization of the Pseudomonas aeruginosa 101/1477 metallo-β-lactamase IMP-1 produced by Escherichia coli

FRANCESCHINI, Nicola;AMICOSANTE, Gianfranco;
1999-01-01

Abstract

The bla(IMP) gene coding for the IMP-1 metallo-β-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-β-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-β-lactamase was not pH dependent.
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11697/103155
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