Evaluation of inhibition of the carbenicillin-hydrolyzing beta-lactamase PSE-4 by the clinically used mechanism-based inhibitors.
FEBS Lett
; 470(3): 285-92, 2000 Mar 31.
Article
em En
| MEDLINE
| ID: mdl-10745083
ABSTRACT
Characterization of the biochemical steps in the inactivation chemistry of clavulanic acid, sulbactam and tazobactam with the carbenicillin-hydrolyzing beta-lactamase PSE-4 from Pseudomonas aeruginosa is described. Although tazobactam showed the highest affinity to the enzyme, all three inactivators were excellent inhibitors for this enzyme. Transient inhibition was observed for the three inactivators before the onset of irreversible inactivation of the enzyme. Partition ratios (k(cat)/k(inact)) of 11, 41 and 131 were obtained with clavulanic acid, tazobactam and sulbactam, respectively. Furthermore, these values were found to be 14-fold, 3-fold and 80-fold lower, respectively, than the values obtained for the clinically important TEM-1 beta-lactamase. The kinetic findings were put in perspective by determining the computational models for the pre-acylation complexes and the immediate acyl-enzyme intermediates for all three inactivators. A discussion of the pertinent structural factors is presented, with PSE-4 showing subtle differences in interactions with the three inhibitors compared to the TEM-1 enzyme.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Pseudomonas aeruginosa
/
Beta-Lactamases
/
Carbenicilina
/
Inibidores Enzimáticos
/
Inibidores de beta-Lactamases
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
FEBS Lett
Ano de publicação:
2000
Tipo de documento:
Article
País de afiliação:
Canadá