Reaction catalyzed by aminopeptidase B (3.4.11.6), TET2 peptidase (3.4.11.B9), Xaa-Pro dipeptidyl-peptidase (3.4.14.11)

		+		H2O	=			+
	Ala-Ala 4-nitroanilide	+		H2O	=		Ala-Ala	+		4-nitroaniline