title: Heme/copper assembly mediated nitrite and nitric oxide interconversion.
abstract: The heme(a3)/Cu(B) 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 NO(2)(-) ion, producing nitric oxide. The heme serves as the reductant, but the Cu(II) ion is also required. In turn, a μ-oxo heme-Fe(III)-O-Cu(II) complex facilitates NO oxidation to nitrite; the final products are the reduced heme and Cu(II)-nitrito complexes.
authors.affiliation: Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218, USA.
authors.forename: Shabnam
authors.initials: S
authors.lastname: Hematian
authors.forename: Maxime A
authors.initials: MA
authors.lastname: Siegler
authors.forename: Kenneth D
authors.initials: KD
authors.lastname: Karlin
mesh_terms: D003300:Copper / Q000737:chemistry*; D006418:Heme / Q000737:chemistry*; D009569:Nitric Oxide / Q000737:chemistry*; D009573:Nitrites / Q000737:chemistry*; D010084:Oxidation-Reduction; D013056:Spectrophotometry, Ultraviolet
chemical_list: D009573:Nitrites; D009569:Nitric Oxide; D006418:Heme; D003300:Copper