Table 2. Kinetics parameters of IR45 and its mutants for the conversion of 1a–5a ^a .

Subs.	IR45			F190L–W191F			F190M–W191F
	K m [mM]	k cat [s–1]	k cat/Km [s–1 mM–1]	K m [mM]	k cat [s–1]	k cat/Km [s–1 mM–1]	K m [mM]	k cat [s–1]	k cat/Km [s–1 mM–1]
1a	0.154	0.020	0.129	0.123	0.009	0.076	0.108	0.031	0.288
2a	NA	NA	NA	0.307	0.003	0.011	NA	NA	NA
3a	NA	NA	NA	0.372	0.032	0.087	NA	NA	NA
4a	0.148	0.021	0.146	0.252	0.049	0.196	0.251	0.248	0.989
5a	0.518	0.090	0.174	0.353	0.041	0.117	0.178	0.054	0.306

^aNA indicates no activity.