title: [Selective chemical modification of cytochrome P450scc (CYP11A1) with diiodofluorescein iodoacetamide in the study of the role and topology of interdomain hinge of the hemoprotein molecule].
abstract: Bovine adrenocortical cytochrome P450scc (CYP11A1) was selectively modified with diiodofluorescein iodoacetamide (DIFIA). Only Cys264 is labeled in the P450 polypeptide chain. The modification significantly affected the cholesterol-hydroxylating activity in the reconstituted system containing NADPH, adrenodoxin reductase, adrenodoxin, and soluble or membrane-bound P450scc. The inhibitory effect correlates with decreased affinity of cytochrome P450scc to intermediate electron carrier, adrenodoxin. Cytochrome P450scc is modified in liposomes and the modified membrane-bound protein is cleaved by trypsin forming two large fragments F1 and F2 corresponding to the N- and C-terminal regions of the molecule. The data indicate that the Cys264-containing region of the cytochrome P450scc molecule is exposed to the surface of protein globule, located outside of the membrane, and can participate in protein-protein interactions.
authors.forename: A A
authors.initials: AA
authors.lastname: Chernogolov
authors.forename: D
authors.initials: D
authors.lastname: Schwarz
authors.forename: S A
authors.initials: SA
authors.lastname: Usanov
mesh_terms: D000302:Adrenal Cortex / Q000201:enzymology; D000325:Adrenodoxin / Q000737:chemistry; D000818:Animals; D002417:Cattle; D002786:Cholesterol Side-Chain Cleavage Enzyme / Q000737:chemistry*; D003545:Cysteine / Q000737:chemistry; D005452:Fluoresceins; D005456:Fluorescent Dyes; D007460:Iodoacetamide / Q000031:analogs & derivatives*; D008081:Liposomes / Q000737:chemistry; D008565:Membrane Proteins / Q000737:chemistry*; D011510:Proteolipids / Q000737:chemistry
chemical_list: D005452:Fluoresceins; D005456:Fluorescent Dyes; D008081:Liposomes; D008565:Membrane Proteins; D011510:Proteolipids; C083114:diiodofluorescein iodoacetamide; C020485:proteoliposomes; D000325:Adrenodoxin; D002786:Cholesterol Side-Chain Cleavage Enzyme; D003545:Cysteine; D007460:Iodoacetamide
vernacular_title: Selektivnaia khimicheskaia modifikatsiia tsitokhroma P450scc (CYP11A1) diiodofluorosceiniodoatsetamidom v issledovanii roli i topologii mezhdomennogo uchastka molekuly gemoproteina.