title: Heme/non-heme diiron(II) complexes and O2, CO, and NO adducts as reduced and substrate-bound models for the active site of bacterial nitric oxide reductase.
abstract: As a first generation model for the reactive reduced active-site form of bacterial nitric oxide reductase, a heme/non-heme diiron(II) complex [(6L)Fe(II)...Fe(II)-(Cl)]+ (2) {where 6L = partially fluorinated tetraphenylporphyrin with a tethered tetradentate TMPA chelate; TMPA = tris(2-pyridyl)amine} was generated by reduction of the corresponding mu-oxo diferric compound [(6L)Fe(III)-O-Fe(III)-Cl]+ (1). Coordination chemistry models for reactions of reduced NOR with O2, CO, and NO were also developed. With O2 and CO, adducts are formed, [(6L)Fe(III)(O2-))(thf)...Fe(II)-Cl]B(C6F5)4 (2a x O2) {lambda(max) 418 (Soret), 536 nm; nu(O-O) = 1176 cm(-1), nu(Fe-O) = 574 cm(-1) and [(6L)Fe(II)(CO)(thf)Fe(II)-Cl]B(C6F5)4 (2a x CO) {nu(CO) 1969 cm(-1)}, respectively. Reaction of purified nitric oxide with 2 leads to the dinitrosyl complex [(6L)Fe(NO)Fe(NO)-Cl]B(C6F5)4 (2a x (NO)2) with nu(NO) absorptions at 1798 cm(-1) (non-heme Fe-NO) and 1689 cm(-1) (heme-NO).
authors.affiliation: Department of Chemistry, Johns Hopkins University, Charles and 34 Streets, Baltimore, Maryland 21218, USA.
authors.forename: Ian M
authors.initials: IM
authors.lastname: Wasser
authors.forename: Hong-wei
authors.initials: HW
authors.lastname: Huang
authors.forename: Pierre
authors.initials: P
authors.lastname: Moënne-Loccoz
authors.forename: Kenneth D
authors.initials: KD
authors.lastname: Karlin
mesh_terms: D001665:Binding Sites; D040761:Biomimetic Materials / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism; D002248:Carbon Monoxide / Q000737:chemistry / Q000378:metabolism; D005296:Ferrous Compounds / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D006418:Heme / Q000737:chemistry* / Q000378:metabolism; D007502:Iron Chelating Agents / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D009569:Nitric Oxide / Q000737:chemistry / Q000378:metabolism; D010088:Oxidoreductases / Q000737:chemistry* / Q000378:metabolism; D010100:Oxygen / Q000737:chemistry / Q000378:metabolism; D011166:Porphyrins / Q000737:chemistry; D011725:Pyridines / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013059:Spectrum Analysis, Raman
chemical_list: D005296:Ferrous Compounds; D007502:Iron Chelating Agents; D011166:Porphyrins; D011725:Pyridines; C409084:tetraphenylporphyrin; C431843:tris(2-pyridylmethyl)amine; D009569:Nitric Oxide; D006418:Heme; D002248:Carbon Monoxide; D010088:Oxidoreductases; C034747:nitric-oxide reductase; D010100:Oxygen