Table 1.

Kinetics of nicotinamide cofactor oxidation by SMFMO and mutants of Gln193 and His194.

SMFMO variant	Km (NADH M x 10−6)	kcat (NADH s−1)	kcat/Km (NADH s−1 M−1)	Km (NADPH M x 10−6)	kcat (NADPH s−1)	kcat/Km (NADPH s−1 M−1)
Wild-type	23.7 ± 9.1	0.029 ± 0.003	1223	27.3 ± 5.3	0.022 ± 0.002	805
Gln193Arg	21.2 ± 4.3	0.031 ± 0.003	1476	8.3 ± 1.6	0.007 ± 0.0005	875
His194Thr	14.1 ± 2.9	0.012 ± 0.0008	857	4.2 ± 0.7	0.012 ± 0.0004	3000
Gln193Arg/His194Thr	12.8 ± 6.9	0.010 ± 0.002	769	4.1 ± 2.8	0.003 ± 0.0003	743