American Chemical Society
ja3083818_si_003.pdf (2.25 MB)

Heme/Copper Assembly Mediated Nitrite and Nitric Oxide Interconversion

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journal contribution
posted on 2012-11-21, 00:00 authored by Shabnam Hematian, Maxime A. Siegler, Kenneth D. Karlin
The hemea3/CuB active site of cytochrome c oxidase is responsible for cellular nitrite reduction to nitric oxide; the same center can return NO to the nitrite pool via oxidative chemistry. Here, we show that a partially reduced heme/Cu assembly reduces NO2 ion, producing nitric oxide. The heme serves as the reductant, but the CuII ion is also required. In turn, a μ-oxo heme-FeIII–O–CuII complex facilitates NO oxidation to nitrite; the final products are the reduced heme and CuII–nitrito complexes.