These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Physical characterization of the activated and non-activated forms of the glucocorticoid-receptor complex bound to the steroid antagonist [3H]RU 486.
    Author: Sablonniere B, Danze PM, Formstecher P, Lefebvre P, Dautrevaux M.
    Journal: J Steroid Biochem; 1986 Nov; 25(5A):605-14. PubMed ID: 3795940.
    Abstract:
    We have compared the physicochemical characteristics of the non-activated (molybdate stabilized) glucocorticoid-receptor complex bound either to [3H]triamcinolone acetonide or to the antagonist [3H]RU 486 with those of the activated (25 degrees C preheated) complexes. The level of activation was measured by a DNA cellulose assay. The physicochemical features of the steroid-receptor complexes were analyzed by various techniques including high-performance size exclusion chromatography, sucrose gradient sedimentation and high-performance DEAE ion exchange chromatography. All the buffers used during the analytical procedures contained sodium molybdate in order to prevent any dissociation of the steroid-receptor complex. The non-activated glucocorticoid receptor bound either to [3H]TA or to [3H]RU 486 sedimented at 9.3S on sucrose gradient, displayed at 70 A Stokes radius in high performance size exclusion chromatography on TSK G4000 SW column, and was eluted at 0.22-0.28 M KCl by anion-exchange chromatography on a DEAE 545 column. After activation the Stokes radius and the sedimentation coefficient declined to 50 A and 4.5S respectively, and the complex was eluted by 0.10-0.12 M KCl on the ion-exchange column. No qualitative difference could be detected between the characteristics of the glucocorticoid-receptor complexes bound either to [3H]TA or to [3H]RU 486. Moreover, the relative distribution of "non-activated" and "activated" forms of the glucocorticoid receptor obtained through physicochemical experiments was highly correlated with the activation level determined by DNA binding experiments. However the activation level of [3H]RU 486-glucocorticoid-receptor complex appeared markedly decreased (15%) when compared with that of the agonist [3H]TA-receptor complex (65%). Experiments done with an antagonist steroid of the 17 beta-carboxamide series of dexamethasone exhibit the same results with an activation level of 12% as compared with triamcinolone acetonide. Thus, two antihormones which have different structures show the same behavior towards the glucocorticoid-receptor complex by strikingly reducing both the activation process and the size reduction of the steroid-receptor complex which is concomitant to activation and which could constitute the first step of this process.
    [Abstract] [Full Text] [Related] [New Search]