Phenylpropynal, a specific, irreversible, non-beta-lactam inhibitor of beta-lactamases.
Phenylpropynal is a specific, irreversible, non-beta-lactam inhibitor of typical beta-lactamases. In the presence of millimolar concentrations of phenylpropynal, the beta-lactamase I of Bacillus cereus and the beta-lactamases of Staphylococcus aureus and Escherichia coli become completely inactivated; the beta-lactamase II of B. cereus is not affected. The E. coli beta-lactamase is considerably more sensitive to the reagent than the gram-positive enzymes. A variety of structural analogs of phenylpropynal are much less effective inhibitors. Bovine alpha-chymotrypsin, bovine carboxypeptidase A, and the D,D-carboxypeptidase/transpeptidase of Streptomyces R-61 were not inactivated by phenylpropynal. The inactivation of the E. coli beta-lactamase can be significantly retarded when the good substrate benzylpenicillin is also present. The development of a characteristic chromophore (lambda max 318 nm) during beta-lactamase inactivation suggests that covalent modification of the enxymes is involved; arginine and/or lysine modification is indicated.
D000447:Aldehydes; D001409:Bacillus cereus / Q000201:enzymology*; D004926:Escherichia coli / Q000201:enzymology*; D013045:Species Specificity; D013211:Staphylococcus aureus / Q000201:enzymology*; D013302:Streptomyces / Q000201:enzymology*; D013329:Structure-Activity Relationship; D065093:beta-Lactamase Inhibitors
D000447:Aldehydes; D065093:beta-Lactamase Inhibitors; C022839:phenylpropynal