S-Nitrosothiols as novel, reversible inhibitors of human rhinovirus 3C protease

Human rhinovirus (HRV) 3C protease was inactivated by a series of S-nitrosothiols. These compounds exhibited different inhibitory activities in a time- and concentration-dependent manner with second-order rate constants (kinact/KI) ranging from 131 to 5360 M−1 min−1. The inactive enzyme could be re-activated by DTT, GSH and ascorbate, which indicated the inactivation mechanism was through an S-transnitrosylation process.