Neuronal nitric oxide synthase: prototype for pulsed enzymology.
The established paradigm in understanding and describing enzyme activity uses formalisms based on steady-state assumptions, including Michaelis-Menten and King-Altman approaches. These are appropriate for enzymes operating under steady-state conditions. Signal generating enzymes transfer information, rather than material. Because the information capacity of a signal channel depends on frequency, steady-state descriptions may not be appropriate. Recently, Stuehr and coworkers described a novel product inhibition mechanism for NO synthases. Simulations presented here suggest that at physiological temperatures neuronal nitric oxide synthase produces sharp pulses of NO, consistent with its signaling function. These temporal pulses greatly restrict the effective spatial range of NO signaling.
Salerno
John C
JC
Biology Department, Kennesaw State University, 1000 Chastain Road, Kennesaw, GA 30144, USA. jsalern3@kennesaw.edu
D000818:Animals; D003198:Computer Simulation; D025461:Feedback, Physiological; D006801:Humans; D008956:Models, Chemical; D009569:Nitric Oxide / Q000096:biosynthesis*; D052248:Nitric Oxide Synthase Type I / Q000037:antagonists & inhibitors* / Q000737:chemistry*; D013696:Temperature
D009569:Nitric Oxide; D052248:Nitric Oxide Synthase Type I