Table 2. Kinetic parameters of purified sGC inhibited by ATP.

	KM, μM	Vmax, nmoles cGMP produced/min per mg of protein
Control	156 + 5	750 + 111
1 mM ATP	356 + 86*	468 + 48*

K_M and V_max values were extracted from nonlinear regression analyses of Michaelis—Menten analyses of sGC stimulated by 100 μM SNP in the presence of different concentrations of Mg-GTP and in the absence or presence of 1 mM ATP (see Fig. 1). Values are means ± SEM of three experiments performed in triplicate.

^*P < 0.05 with respect to control (no added ATP) using a paired Student t test (two-tailed).