Reaction catalyzed by cytosol nonspecific dipeptidase (3.4.13.18), dipeptidyl-peptidase II (3.4.14.2), Xaa-Pro dipeptidyl-peptidase (3.4.14.11), Xaa-Xaa-Pro tripeptidyl-peptidase (3.4.14.12)

		+		H2O	=			+
	Lys-Pro-p-nitroanilide	+		H2O	=		Lys-Pro	+		p-nitroaniline