TABLE 2.

Mechanism of inhibition of GSNOR by GSNOR inhibitors

The K_is and K_ii are the slope and intercept inhibition constant estimates and are listed with their associated S.E. values. The data were fit to a competitive, noncompetitive (NC), or uncompetitive (UC) inhibition model. The type of inhibition shown represents the best fit of the data to the given model as judged from F statistics analysis.

Compound	Varied substrate	Type of inhibition	Kis	Kii	KDa
			μm	μm	μm
C1	GSNO	NC	1.7 ± 0.2	1.8 ± 0.1	1.3 ± 0.3
	NADH	UC		1.5 ± 0.1
C2	GSNO	NC	1.9 ± 0.2	4.0 ± 0.3	6.5 ± 1.0
	NADH	NC	12 ± 5	2.5 ± 0.1
C3	GSNO	NC	2.6 ± 0.3	1.6 ± 0.1	2.0 ± 0.1
	NADH	UC		1.7 ± 0.1
Dodecanoic acid	GSNO	NC	280 ± 40	190 ± 10

^a K_D is the equilibrium dissociation constant of the inhibitor for binding to the GSNOR·NADH complex, obtained by measuring the changes in the fluorescence of GSNOR-bound NADH with the addition of inhibitor (λ_ex = 350 nm; λ_em = 455 nm). The dissociation constant was measured at 25 °C in 50 mm potassium phosphate, pH 7.5. Each K_D value is an average of three independent experiments and is shown with the associated S.E.