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Effects of Penicillins and 6-aminohexanoic Acid on the Kinetics of Human Plasmin

A A Higazi, M Mayer

Biochem J. 1989 Jun 1;260(2):609-12.

PMID: 2527494

Abstract:

Human plasmin activity is inhibited by various penicillins in a dose-dependent manner. Ampicillin and cloxacillin produce a 50% inhibition of the globinolytic activity of plasmin at 4.5 and 5.3 mM respectively. A lower inhibitory capacity is displayed by carbenicillin. Assay of plasmin by its amidolytic activity on D-valyl-L-leucyl-L-lysine p-nitroanilide dihydrochloride showed that ampicillin at a concentration producing half-maximal inhibition converted the hyperbolic activity-substrate concentration curve into a sigmoidal curve. A similar conversion occurred in the presence of ampicillin when plasmin was assayed with an alternative chromogenic substrate, L-pyroglutamyl-glycyl-L-arginine p-nitroanilide hydrochloride 6-Aminohexanoic acid at 7.5 microM abolished the inhibition of plasmin induced by ampicillin. The present observations suggest that ampicillin interacts with plasmin at a regulatory site different from the active site of the enzyme. The effect of 6-aminohexanoic acid indicates that the lysine-binding site may be part of a regulatory site. It is possible that modulation of plasmin activity by ligands plays a role in the control of fibrinolysis.

Chemicals Related in the Paper:

Catalog Number Product Name Structure CAS Number Price
AP40127115 L-Arginine p-nitroanilide dihydrochloride L-Arginine p-nitroanilide dihydrochloride 40127-11-5 Price
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