TABLE 2.

Folded stability, kinetic activity, and substrate affinity of hallmark Photox mutants

Measurements were obtained as described under “Experimental Procedures” and represent the mean ± S.D. Trp λ emission measurements represent at least 3 replicates; mART activity, at least 5 replicates.

Photox mutant	Trp λ emission maximum	Relative kcat	Relative KD
	nm	mART activity	NAD+
Wild-type	344 ± 0.6	1.00	1.00 ± 0.03
E353A	343 ± 0.6	0.00156	1.22 ± 0.08
E355A	344 ± 0.1	0.0000737	3.67 ± 0.14
R288A	343 ± 0.1	≈0a	4.28 ± 0.45
STS/ATA	343 ± 0.1	0.000470	5.41 ± 1.07

^a Measurement could not be accurately determined as it was near background levels.