Table 2. Steady state kinetic constants of S. coelicolor Hms for a range of aromatic 2-oxo acids and corresponding product enantiopurity.

Substrate	Km	kcat	Enantiomeric purity
	(µM)	(s−1)	% (S)-enantiomer
HPP	220±80	4.5±0.5	n.d.
Phenylpyruvic acid	353±87	0.88±0.09	99.6±0.4
p-Methylphenylpyruvic acid	n.d.	0.13±0.02	>99*
p-Methoxyphenylpyruvic acid	160±70	0.96±0.12	55±2
p-Fluorophenylpyruvic acid	n.d.	0.077±0.004	88±2
2-Oxo-4-phenylbutanoic acid	35±20	0.17±0.02	>95*
p-Nitrophenylpyruvic acid	n.d.	0.035±0.007	n.d.

Apparent kinetic constants were determined at air saturation (20 mM Tris buffer, pH 7.5, 25°C).

^*The analytical method did not allow a more precise determination.