Table 2

Specificity constants of wild-type and mutant NAT proteins^2-a

Protein	k_cat/K_m(PAS)	k_cat/K_m(SMZ)	k_cat/K_m(PAS)/k_cat/K_m (SMZ)
NAT1-F¹²⁵A	9.94	25	0.4
NAT1-F¹²⁵S	9.92	10	0.99
NAT1-F¹²⁵T	36	6.97	5.17
NAT1-F¹²⁵V	201	8.53	23.6
NAT1-F¹²⁵Y	180	0.013	13846
Wild-type NAT1	1175	0.078	15064
Wild-type NAT2	0.0028	0.23	0.012

↵2-a k_cat is measured in molecules of acetylated product/molecule of NAT/min,K_m is in micromolar concentrations.