Chemistry Commons^™

Charge-Pairing Interactions Control The Conformational Setpoint And Motions Of The Fmn Domain In Neuronal Nitric Oxide Synthase, Mohammad Mahfuzul Haque, Mekki Bayachou, Mohammed A. Fadlalla, Deborah Durra, Dennis J. Stuehr

Chemistry Faculty Publications

The NOS (nitric oxide synthase; EC 1.14.13.39) enzymes contain a C-terminal flavoprotein domain [NOSred (reductase domain of NOS)] that binds FAD and FMN, and an N-terminal oxygenase domain that binds haem. Evidence suggests that the FMN-binding domain undergoes large conformational motions to shuttle electrons between the NADPH/FAD-binding domain [FNR (ferredoxin NADP-reductase)] and the oxygenase domain. Previously we have shown that three residues on the FMN domain (Glu(762), Glu(816) and Glu(819)) that make charge-pairing interactions with the FNR help to slow electron flux through nNOSred (neuronal NOSred). In the present study, we show that charge neutralization or reversal at each of …