Table 1.

Kinetic parameter for hydrolysis of several synthetic trypsin/fXa-substrates by rfXa, rfXYa, and rtrypsin^*

	rfXa			rfXYa			rtrypsin
	kcat, s−1	Km μM	kcat/Km	kcat, s−1	Km, μM	kcat/Km	kcat, s−1	Km, μM	kcat/Km
Pyro-Glu-Gly-Arg-pNA	83	830	0.1	41	15	2.7	176	85	2.1
Bz-Ile-Glu-Gly-Arg-pNA	118	167	0.7	39	17	2.3	128	43	3.0
MS-D-Phe-Gly-Arg-pNA	138	275	0.5	44	15	2.9	145	30	4.8
MOC-D-Nle-Gly-Arg-pNA	215	199	1.1	52	22	2.4	153	43	3.6
Bz-β-Ala-Gly-Arg-pNA	66	134	0.5	68	49	1.4	225	208	1.1
CB-Val-Gly-Arg-pNA	91	525	0.2	36	13	2.7	95	32	3.0
Bz-Pro-Phe-Arg-pNA	53	265	0.2	119	115	1.0	38	17	2.2
D-Val-CHA-Arg-pNA	95	1480	0.1	91	68	1.3	46	129	0.4
Tos-Gly-Pro-Arg-pNA	107	149	0.7	39	23	1.7	95	13	7.3
Tos-Gly-Pro-Lys-pNA	44	540	0.06	55	67	0.8	26	56	0.5

The parameters of preferred substrates for each enzyme are emphasized in bold. Substrates were chosen according to commercial availability and variation of P1, P2, and P3. 

^*The SE is 5–15%. 

Bz, benzyl; CB, carbobenzoxy; CHA, cyclohexylalanyl; MOC, methoxycarbonyl; MS, methylsulfonyl; pNA, p-nitroanilin; Tos; tosyl.