Open AccessIdentification of the Ah receptor in selected mammalian species and induction of aryl hydrocarbon hydroxylase
Author(s) -
DENISON Michael S.,
WILKINSON Christopher F.
Publication year - 1985
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1985.tb08767.x
Subject(s) - cytosol , aryl hydrocarbon receptor , receptor , methylcholanthrene , chemistry , pyrene , aryl , hamster , biochemistry , benzo(a)pyrene , ligand (biochemistry) , enzyme inducer , stereochemistry , enzyme , carcinogen , biology , microbiology and biotechnology , transcription factor , organic chemistry , alkyl , gene
The Ah receptor protein, important in the mechanism of induction of aryl hydrocarbon hydroxylase activity, has been identified and partially characterized in hepatic cytosolic preparations from rat, BALB/c mouse, gerbil, hamster, rabbit, ferret and guinea‐pig by means of sucrose density centrifugation analysis and hydroxyapatite binding assays. Using 2,3,7,8‐tetrachloro[ 3 H]dibenzo‐ p ‐dioxin (TCDD) as the ligand, total specific binding capacities ranged over 74–691 fmol [ 3 H]TCDD/mg cytosolic protein and apparent dissociation constats ranged over 0.30–7.8 nM. There was no quantitative correlation between the concentration of cytosolic Ah receptors and the 3‐methylcholanthrene‐mediated induction of aryl hydrocarbon hydroxylase activity in the species studied. Competitive binding studies with a series of monohydroxylated benzo[ a ]pyrene derivatives suggested the importance of electronic character in their ability to bind to the Ah receptor and to compete with TCDD for specific binding sites on the receptor.