title: Covalent binding of benzo[a]pyrene to rat liver cytosolic proteins and its effect on the binding to microsomal proteins.
abstract: Benzo[a]pyrene will bind covalently to rat liver cytosolic proteins when incubated with microsomes and NADPH. The binding is most extensive when microsomes from 3-methylcholanthrene-treated rather than phenobarbital-treated or control rats are used. The binding to cytosolic proteins increases when incubations are performed with increasing concentrations of cytosol. At the same time the covalent binding of benzo[a]pyrene to microsomal proteins decreases. Two cytosolic polypeptides are the main targets for benzo[a]pyrene. These have the same mobility in polyacrylamide gels as the subunits of purified glutathione S-transferase B. These subunits also react covalently with benzo[a]pyrene when the transferase is incubated with microsomes and NADPH.
mesh_terms: D000818:Animals; D001564:Benzo(a)pyrene; D001580:Benzopyrenes / Q000378:metabolism*; D002273:Carcinogens / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism; D007700:Kinetics; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008748:Methylcholanthrene / Q000494:pharmacology; D008862:Microsomes, Liver / Q000378:metabolism*; D008970:Molecular Weight; D010634:Phenobarbital / Q000494:pharmacology; D011485:Protein Binding; D011506:Proteins / Q000302:isolation & purification / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D001580:Benzopyrenes; D002273:Carcinogens; D011506:Proteins; D001564:Benzo(a)pyrene; D008748:Methylcholanthrene; D010634:Phenobarbital