Reversible dissociation of triiodothyronine-nuclear receptor complexes by mercurial and chaotropic reagents
Ferreira, M.M.; Bismuth, J.; Torresani, J.
Biochemical and Biophysical Research Communications 105(1): 244-251
1982
ISSN/ISBN: 0006-291X PMID: 6284144 Document Number: 184484
Triiodothyronine[T3]-nuclear receptor complexes from partially purified preparations of the rat liver receptor may be completely dissociated by 0.1 mM parahydroxymercuribenzoate (PHMB) or 0.5 M sodium thiocyanate (NaSCN). PHMB effect was totally reversed by addition of excess sulfhydryl groups. NaSCN effect was also totally reversed by elimination of the reagent by dialysis. The same binding component was recovered as verified by chromatography on Sephadex G-100 columns, without changes of the binding parameters determined by Scatchard analysis. Furthermore, low concentrations of NaSCN (20 mM) were able to increase .apprx. 1.5 fold the dissociation rate constant of T3 binding to its partially purified receptor at 0.degree. C, with minor alterations of maximum binding.