Fig. 4.

Effect of thiols on XOR-catalyzed reduction of NDHP and nitroglycerin (GTN) to NO. The presence of L-cysteine induced no changes in NO formation from either NDHP or GTN. The experimental conditions were: 1 mL reactional buffer (PBS, pH 7.4) containing XOR (0.05 U/mL), NDHP (1 mM) or GNT (1 mM), NADH (1 mM), in the presence or absence of L-cysteine (5 mM). Data are shown as mean ± S.E.M. (n = 4).