Time-dependent inhibition of neuronal nitric oxide synthase by N-propargylguanidine

N-Propargylguanidine was synthesized and found to be a time-dependent inhibitor of neuronal nitric oxide synthase from bovine brain. No inactivation occurs when NADP+ is substituted for NADPH, inhibition is blocked by L-arginine, but not D-arginine, and no enzyme reactivation occurs by dilution of inactivated enzyme with excess L-arginine.