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.
Danzé
P M
PM
Laboratoire de Biochimie Structurale, Faculté de Médecine, Lille, France.
Richard
C
C
Formstecher
P
P
Dautrevaux
M
M
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