Binding of Thienamycin and Clavulanic Acid to the Penicillin-Binding Proteins of Escherichia coli K-12
AUTOR(ES)
Spratt, Brian G.
RESUMO
Thienamycin and clavulanic acid are new β-lactam derivatives with structures markedly different from those of penicillins or cephalosporins. Both derivatives had the same general mode of action as typical β-lactam antibiotics since they bound to precisely the same proteins as [14C]benzylpenicillin. Thienamycin showed high affinity for penicillin-binding proteins 1, 2, 4, 5, and 6 and a lower affinity for protein 3. Protein 2 had the highest affinity for thienamycin, and concentrations from the minimal morphological change concentration (0.1 μg/ml) up to about 0.6 μg/ml resulted in the conversion of Escherichia coli KN126 into large osmotically stable round cells. Above a concentration of 0.6 μg/ml, rapid cell lysis occurred with the release of the cell contents as spheroplasts. Clavulanic acid showed good affinity for penicillin-binding protein 2, moderate affinity for proteins 1, 4, 5, and 6, and low affinity for protein 3. Protein 2 had the highest affinity for clavulanic acid, and concentrations from the minimal morphological change concentration (30 μg/ml) up to about 50 μg/ml produced a mixture of slightly elongated, swollen, bulging, and lemon-shaped cells. Above a concentration of 50 μg/ml, rapid lysis occurred with production of spheroplasts. The properties of thienamycin and clavulanic acid were compared with those of the penicillins, cephalosporins, and amidinopenicillanic acids.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=429926Documentos Relacionados
- Affinity of temocillin for Escherichia coli K-12 penicillin-binding proteins.
- Affinities of penicillins and cephalosporins for the penicillin-binding proteins of Escherichia coli K-12 and their antibacterial activity.
- Comparison of cefepime, cefpirome, and cefaclidine binding affinities for penicillin-binding proteins in Escherichia coli K-12 and Pseudomonas aeruginosa SC8329.
- Inhibition of Escherichia coli K-12 by β-Lactam Antibiotics With Poor Antibacterial Activity: Interaction of Permeability And Intrinsic Activity Against Penicillin-Binding Proteins
- Inhibition of Escherichia coli K-12 by β-Lactam Antibiotics With Poor Antibacterial Activity: Interaction of Permeability and Intrinsic Activity Against Penicillin-Binding Proteins