Mitochondrial rhodanese: membrane-bound and complexed activity.
J Biol Chem
; 265(14): 8087-93, 1990 May 15.
Article
en En
| MEDLINE
| ID: mdl-2335518
We have proposed that phosphorylated and dephosphorylated forms of the mitochondrial sulfurtransferase, rhodanese, function as converter enzymes that interact with membrane-bound iron-sulfur centers of the electron transport chain to modulate the rate of mitochondrial respiration (Ogata, K., Dai, X., and Volini, M. (1989) J. Biol. Chem. 204, 2718-2725). In the present studies, we have explored some structural aspects of the mitochondrial rhodanese system. By sequential extraction of lysed mitochondria with phosphate buffer and phosphate buffer containing 20 mM cholate, we have shown that 30% of the rhodanese activity of bovine liver is membrane-bound. Resolution of cholate extracts on Sephadex G-100 indicates that part of the bound rhodanese is complexed with other mitochondrial proteins. Tests with the complex show that it forms iron-sulfur centers when incubated with the rhodanese sulfur-donor substrate thiosulfate, iron ions, and a reducing agent. Experiments on the rhodanese activity of rat liver mitochondria give similar results. Taken together, the findings indicate that liver rhodanese is in part bound to the mitochondrial membrane as a component of a multiprotein complex that forms iron-sulfur centers. The findings are consistent with the role we propose for rhodanese in the modulation of mitochondrial respiratory activity.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Sulfurtransferasas
/
Tiosulfato Azufretransferasa
/
Mitocondrias Hepáticas
/
Proteínas
/
Membranas Intracelulares
Límite:
Animals
Idioma:
En
Revista:
J Biol Chem
Año:
1990
Tipo del documento:
Article
Pais de publicación:
Estados Unidos