Superoxo, mu-peroxo, and mu-oxo complexes from heme/O2 and heme-Cu/O2 reactivity: copper ligand influences in cytochrome c oxidase models.
Proc Natl Acad Sci U S A
; 100(7): 3623-8, 2003 Apr 01.
Article
en En
| MEDLINE
| ID: mdl-12655050
ABSTRACT
The O(2)-reaction chemistry of 11 mixtures of (F(8))Fe(II) (1; F(8) = tetrakis(2,6-diflurorophenyl)porphyrinate) and [(L(Me(2))N)Cu(I)](+) (2; L(Me(2))N = N,N-bis(2-[2-(N',N'-4-dimethylamino)pyridyl]ethyl)methylamine) is described, to model aspects of the chemistry occurring in cytochrome c oxidase. Spectroscopic investigations, along with stopped-flow kinetics, reveal that low-temperature oxygenation of 1/2 leads to rapid formation of a heme-superoxo species (F(8))Fe(III)-(O(2)(-)) (3), whether or not 2 is present. Complex 3 subsequently reacts with 2 to form [(F(8))Fe(III)-(O(2)(2-))-Cu(II)(L(Me(2))N)](+) (4), which thermally converts to [(F(8))Fe(III)-(O)-Cu(II)(L(Me(2))N)](+) (5), which has an unusually bent (Fe-O-Cu) bond moiety. Tridentate chelation, compared with tetradentate, is shown to dramatically lower the nu(O-O) values observed in 4 and give rise to the novel structural features in 5.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Oxígeno
/
Complejo IV de Transporte de Electrones
/
Hemo
Idioma:
En
Revista:
Proc Natl Acad Sci U S A
Año:
2003
Tipo del documento:
Article
País de afiliación:
Estados Unidos