Biological relevance of metal complexes of nitric oxide

Article By:

Boon, Elizabeth M. Department of Chemistry, Stony Brook University, Stony Brook, New York.

Muralidharan, Sandhya Department of Chemistry, Stony Brook University, Stony Brook, New York.

Last reviewed:2014

DOI:https://doi.org/10.1036/1097-8542.YB140346

Nitric oxide (NO) is a diffusible free-radical gas. It has well-characterized reactivity with molecules such as molecular oxygen (O₂), metal ions, and thiols, but the physiological function of NO is intimately linked to its in vivo concentration. At high concentrations, NO is a potent toxin used to kill invading pathogens and tumor cells by indiscriminately reacting with cellular components. At relatively low concentrations (≤ micromolar), NO typically reacts with the metal centers (usually iron) of specific metalloproteins, where it mediates cellular response to nitrosative stress. At very low concentrations (≤ nanomolar), NO functions as a signaling molecule that regulates many physiological functions such as vasodilation and neurotransmission through its interaction with a selective, sensitive, and reversible sensor.

The content above is only an excerpt.