Table 8

N-Oxygenation of phenethylamine 1 and its corresponding hydroxylamine 2 by FMO3-MBP

Substrate	Enzyme	K_mapp^8-a	V_max	V_max/K_mapp
		mM	nmol/min/mg of protein
Phenethylamine	Lys¹⁵⁸FMO3-MBP	0.197	19.3	97.99
	Glu¹⁵⁸FMO3-MBP	0.0904	28.2	311.9
Phenethylamine hydroxylamine	Lys¹⁵⁸ FMO3-MBP	0.467	29.9	64.0
	Glu¹⁵⁸ FMO3-MBP	0.063	12.6	200.0

↵8-a The kinetic constants were determined using the incubation system described in table 1 except it contained variable amounts of phenethylamine 1 or phenethylamine hydroxylamine2 and 99 μg of human Lys¹⁵⁸ FMO3-MBP or Glu¹⁵⁸ FMO3-MBP in potassium phosphate buffer, pH 9.0.