title: A DFT study of the nitric oxide and tyrosyl radical interaction: a proposed radical mechanism.
abstract: The present study employs a complete theoretical investigation, at the B3LYP/cc-pVTZ level of theory, of the interactions between the tyrosyl radical and nitric oxide, exploring in detail the nitrotyrosine formation radical mechanism. Tyrosyl radicals play an essential role in catalytic reactions of numerous enzymes and biological systems have regulated appropriate mechanisms for their formation. Nitric oxide reacts with the tyrosyl radical and affords a weak intermediate complex which, through a sequence of non-ionic water catalyzed and biologically feasible intermediate reactions, yields the iminoxyl radical. The iminoxyl radical further combines with hydroxyl radical, a species present in pathophysiological conditions, to yield nitrotyrosine.
authors.affiliation: Department of Chemistry, University of Ioannina, 451 10 Ioannina, Greece.
authors.forename: Konstantinos D
authors.initials: KD
authors.lastname: Papavasileiou
authors.forename: Theodora D
authors.initials: TD
authors.lastname: Tzima
authors.forename: Yiannis
authors.initials: Y
authors.lastname: Sanakis
authors.forename: Vasilios S
authors.initials: VS
authors.lastname: Melissas
mesh_terms: D002384:Catalysis; D002627:Chemistry, Physical / Q000379:methods*; D005609:Free Radicals; D006860:Hydrogen Bonding; D007097:Imines / Q000737:chemistry; D007477:Ions; D008956:Models, Chemical; D008962:Models, Theoretical; D008968:Molecular Conformation; D009566:Nitrates / Q000737:chemistry; D009569:Nitric Oxide / Q000737:chemistry*; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D005609:Free Radicals; D007097:Imines; D007477:Ions; D009566:Nitrates; C066447:tyrosyl radical Y(D); D014867:Water; D009569:Nitric Oxide; C002744:3-nitrotyrosine; D014443:Tyrosine