Reduction of hexavalent chromium in a reconstituted system of cytochrome P-450 and cytochrome b5.
Chem Biol Interact
; 71(2-3): 213-21, 1989.
Article
en En
| MEDLINE
| ID: mdl-2598298
ABSTRACT
The reduction of hexavalent chromium (Cr(VI] by the monooxygenase components was studied. Both a reconstituted system of cytochrome P-450 (P-450) and cytochrome b5 (b5) with NADPH was capable of reducing Na2CrO4 (30 microM) provided anaerobic atmosphere. The rates were 1.29 nmol Cr.min-1 nmol P-450(-1) and 0.73 nmol Cr.min-1 nmol b5(-1). Using NADH instead of NADPH gave very low reducing activities, confirming the enzymic nature of the P-450 dependent Cr(VI) reductase reaction. Oxygen, 22% (air) and 0.1% gave 89% and 69% inhibition of Cr(VI) reducing activity, respectively. Carbon monoxide (100%) caused an inhibition of about 37% and 44% for P-450 and b5, respectively. Externally added flavin mononucleotide (FMN) (3 microM) or Fe-ADP (10 microM) to the complete system stimulated the enzymatic reaction about 2-fold and 3-fold, respectively.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Microsomas Hepáticos
/
Citocromos b5
/
Cromo
/
Sistema Enzimático del Citocromo P-450
Límite:
Animals
Idioma:
En
Revista:
Chem Biol Interact
Año:
1989
Tipo del documento:
Article