Chapter 3 – The Chemical Biology of Nitric Oxide

Publisher Summary The multiple effects of nitric oxide (NO) in biological systems have resulted in intense investigation into the mechanisms of NO-mediated events. The chemistry of NO is the primary determinant of its biological properties. However, not all the reactions of NO that can be performed in test tube are pertinent in vivo. This chapter provides a guide through the diverse reactions of NO in biological systems. The scheme of the chemical biology of NO divides the reactions into the two categories of direct and indirect effects. Direct effects are defined as those reactions that are fast enough to occur between NO and specific biological targets. Indirect effects do not involve NO, but rather, are mediated by reactive NO species formed from the reaction of NO with either oxygen or superoxide. These species can mediate either nitrosative or oxidative stress. Aspects of the chemical biology of NO relating to biological molecules such as guanylate cyclase, cytochrome P-450, nitric oxide synthase, catalase, and DNA are reviewed and the possible roles NO performs in different biological situations are explored.