[Interaction of cholesterol hydroxylating cytochrome P-450 with cytochrome b5].
Some new relations between cytochrome P-450-dependent monooxygenases were discovered. Cytochrome b5, a representative of "microsomal" monooxygenases, was shown to form a highly specific complex with cytochrome P-450scc, a member of the "ferredoxin" monooxygenase family. This interaction is characterized by a dissociation constant, Kd, of 0.28 microM. The cytochrome P-450scc-cytochrome b5 complex may be cross-linked with water-soluble carbodiimide. Using proteolytic modification of cytochrome b5, it was shown that both hydrophilic and hydrophobic fragments of cytochrome b5 are involved in the interaction with cytochrome P-450scc. Cytochrome b5 immobilized via amino groups is an effective affinity matrix for cytochrome P-450scc purification. The role of some amino acid residues in cytochrome P-450scc interaction with cytochrome b5 was studied. The role and the nature of complexes in cytochrome P-450-dependent monooxygenases as well as interrelationships between "microsomal" and "ferredoxin" monooxygenases are discussed.
Usanov
S A
SA
Chashchin
V L
VL
Akhrem
A A
AA
D000302:Adrenal Cortex / Q000201:enzymology; D000325:Adrenodoxin / Q000378:metabolism; D000818:Animals; D002384:Catalysis; D002786:Cholesterol Side-Chain Cleavage Enzyme / Q000378:metabolism*; D003573:Cytochrome b Group / Q000378:metabolism*; D015786:Cytochromes b5; D004579:Electron Transport; D005287:Ferredoxin-NADP Reductase / Q000378:metabolism; D008862:Microsomes, Liver / Q000378:metabolism; D008928:Mitochondria / Q000201:enzymology; D011136:Polysorbates / Q000494:pharmacology; D011817:Rabbits; D013053:Spectrophotometry
D003573:Cytochrome b Group; D011136:Polysorbates; D000325:Adrenodoxin; D015786:Cytochromes b5; D002786:Cholesterol Side-Chain Cleavage Enzyme; D005287:Ferredoxin-NADP Reductase
Vzaimodeĭstvie kholesteringidroksiliruiushchego tsitokhroma P-450 s tsitokhromom b5.