Table 2.

Four different types of fluorescence measurements were used to measure NADH binding affinity for rmGAPDH and byGAPDH.

	rmGAPDH-NADH KD fluorescence measurements	byGAPDH-NADH KD fluorescence measurements
Measurement type	KD in micro Molar + error	KD in micto molar + error
Protein quenchinga	0.84 ± 0.09	8.7 ± 0.6
NADH quenchingb	0.86 ± 0.07	8.5 ± −0.8
FRET protein-NADHc	0.77 ± 0.5	8.0 ± 0.7
Anisotropy NADHd	0.73 ± 0.06	7.6 ± 0.5
Average:	0.8 ± 0.06	8.2 ± 0.5

The K_D constants are shown in terms of NADH binding sites on each tetramer:

^aexcitation 295 nm emission 328 nm; ^bexcitation 328 nm emission 457 nm; ^cexcitation 295 nm emission 457 nm; ^dexcitation 330 nm emission 457 nm.