Binding of reactive metabolites of CCl4 to specific microsomal proteins.
The covalent binding of [14C]carbon tetrachloride to microsomal proteins in rat liver microsomes under anaerobic conditions was investigated by SDS-polyacrylamide slab gel electrophoresis and fluorography. Most of the labeled proteins were observed in the molecular weight range of 52-61 kDa, indicating that cytochrome P-450 forms (EC 1.14.14.1) were labeled. Protein bands at the position of the NADPH-cytochrome P-450 reductase (78 kDa) (EC 1.6.2.4) and NADH-cytochrome b5 reductase (33 kDa) (EC 1.6.2.2) also showed radioactivity. The fluorographic pattern of the protein labeling was cytochrome P-450-dependent, as was demonstrated by CO and metyrapone inhibition as well as by pretreatment of rats with inducing drugs such as 3-methylcholanthrene, benzo(a)pyrene, phenobarbitone and Aroclor 1254. Immuno-precipitation with a purified anti-P-450 immunoglobulin against cytochrome P-450 PB-B (52 kDa) of rat liver indicated that this protein contained about 10-20% of the total bound radioactivity in an average ratio of 0.8 mol [14C]CCl4-metabolite/mol cytochrome P-450 PB-B.
D000693:Anaerobiosis; D000818:Animals; D002250:Carbon Radioisotopes; D002251:Carbon Tetrachloride / Q000378:metabolism*; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D008297:Male; D008862:Microsomes, Liver / Q000378:metabolism*; D010100:Oxygen / Q000494:pharmacology; D011485:Protein Binding; D011506:Proteins / Q000302:isolation & purification / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D002250:Carbon Radioisotopes; D011506:Proteins; D003577:Cytochrome P-450 Enzyme System; D002251:Carbon Tetrachloride; D010100:Oxygen