TABLE 3.

k_cat and K_m values for StyB_rec (and StyB_wt+) for different flavins and electron donors^a

Substrate	Second substrate (200 μm)	kcat (s−1)	Km (μM)	kcatKm−1 (s−1 μM−1)
FMN	NADH	48	7.1 ± 0.7 (7.0 ± 0.5)	6.78
FAD	NADH	47	11.6 ± 1.4 (10.0 ± 0.9)	4.05
Riboflavin	NADH	60	14.7 ± 2.8 (15.0 ± 1.4)	4.08
NADH	FMN	60	21.06 ± 2.6 (25.0 ± 2.0)	2.84
NADPH	FMN		No activity

^aData were calculated by weighted nonlinear regression analysis (Enzfitter^φ; Elsevier-Biosoft. Activities were determined by the standard reductase assay described in Materials and Methods, with 0.7 μg of StyB ml⁻¹ or 80 μg of the StyB-containing fraction from Pseudomonas strain VLB120.