Steroid receptor exchange assay in the presence of acetonitrile: application to the study of glucocorticoid- and anti-glucocorticoid-receptor complexes.
Acetonitrile was used to modify the binding parameters of glucocorticoid-receptor complexes. Acetonitrile (8%) caused a striking increase of the rate constant of dissociation of non-transformed [3H]triamcinolone and [3H]RU 486 receptor complexes. The latter complexes appeared significantly less sensitive to acetonitrile than the former. Similar data were obtained for heat-transformed [3H]triamcinolone and RU 486-receptor complexes purified at a 90% relative homogeneity by DEAE-Trisacryl (diethylaminoethyl) chromatography. The rate constant of dissociation of both steroid-receptor complexes decreased after transformation. The dissociation of non-transformed receptor complexes by acetonitrile was reversible, and an exchange assay allowing 75% to 85% steroid exchange is described. However, the dissociation of transformed receptor complexes appeared completely irreversible and precluded the design of any exchange assay.
Laboratoire de Biochimie Structurale, Faculté de Médecine, Lille, France.
P M
PM
Danzé
C
C
Richard
P
P
Formstecher
M
M
Dautrevaux
D000097:Acetonitriles / Q000494:pharmacology*; D000818:Animals; D002606:Charcoal; D002850:Chromatography, Gel; D003600:Cytosol; D004277:DNA, Single-Stranded; D003911:Dextrans; D006207:Half-Life; D007700:Kinetics; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D011965:Receptors, Glucocorticoid / Q000032:analysis* / Q000187:drug effects / Q000378:metabolism
D000097:Acetonitriles; D004277:DNA, Single-Stranded; D003911:Dextrans; D011965:Receptors, Glucocorticoid; D002606:Charcoal; C032159:acetonitrile