Table 1.

Fluorescence Quantum Yields and Specific Activities

Construct	Quantum Yield		Specific Activitya
	FAD	Trp
WT	0.06	0.08	36±4
	0.05b	0.08
W47F	0.05	0.05	48±3
	0.05	0.05
W131F	0.02	0.11	20±3
	0.04	0.10
W52F	n.d.c	0.12	42±10
	n.d.c	0.14
Y137F	n.d.c	0.17	32±4

^aSpecific activity (µmol NADH oxidized per minute per mg enzyme) was measured at 22–23 °C with 200 µM NADH and 120 µM FAD.

^bDuplicate entries represent experiments with independent preparations of NOX. The experimental errors of replicate measurements of the quantum yield with the same preparation were approximately ±0.002 for FAD and ±0.01 for Trp.

^cFlavin fluorescence for these constructs was too low to measure Q_FAD reliably.