Detection of a tetrahedral intermediate in the trypsin-catalysed hydrolysis of specific ring-activated anilides

The substituent dependence for kcat/Km of trypsin anilide hydrolysis is consistent with a rate-limiting general acid-base catalysed breakdown of a tetrahedral intermediate. The formation and disappearance of this intermediate during the hydrolysis of alpha-N-acetyl-L-lysin p-nitroanilide is observed in stopped-flow experiments.