The action of trypsin on synthetic chromogenic arginine substrates

A new arginine derivative, N-benzyloxycarbonyl-L-phenylalanyl-L-valyl-L-arginine-p-nitroanilide hydrochloride (ZPVAPA.HCl) was synthesized by the condensation of N-benzyloxy-carbonyl-L-phenylalanyl-L-valine and L-arginine-p-nitroanilide dihydrochloride using dicyclohexylcarbodiimide as a coupling reagent and 1-hydroxy-benzotriazole as an additive. L-ZPVAPA.HCl was split by trypsin more readily than Na-benzyloxycarbonyl-L-arginine-p-nitroanilide hydrochloride (L-ZAPA, HCl), Na-benzoyl-L-arginine-p-nitroanilide hydrochloride (L-BAPA.HCl), Na-tosyl-L-arginine-p-nitroanilide hdyrochloride (L-TAPA.HCl) and Na-benzoyl-DL-arginine-p-nitroanilide hydrochloride (DL-BAPA.HCl) by factors of 100, 400, 600, and 1,200, respectively. Low concentrations of dimethyl formamide (DMF) enhanced the trypsin-catalyzed hydrolyses of L-ZAPA.HCl and L-TAPA.HCl, contrary to the findings of other authors that DMF has no effect on the tryptic hydrolysis.