Inhibition of dexamethasone binding to human glucocorticoid receptor by New World primate cell extracts
| Autor: | John W. Kendall, D. Lynn Loriaux, Kristina Alman, Paula Tower, David D. Brandon |
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| Rok vydání: | 1995 |
| Předmět: |
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Clinical Biochemistry Cell Biology Tritium Biochemistry Dexamethasone Cell Line Endocrinology Glucocorticoid receptor Cytosol Receptors Glucocorticoid medicine Animals Humans Trypsin Lymphocytes Receptor Molecular Biology Pharmacology Organic Chemistry Rats Kinetics medicine.anatomical_structure Cell culture Chromatography Gel Saguinus Glucocorticoid medicine.drug |
| Zdroj: | Steroids. 60(7) |
| ISSN: | 0039-128X |
| Popis: | To determine if New World primates express an inhibitor that influences glucocorticoid receptor (GR) binding characteristics, we examined [3H] dexamethasone binding in cytosol prepared from B95-8 lymphoid cells, derived from the cotton top tamarin (Saguinus oedipus), in combination with cytosol prepared from human or rat tissues. B95-8 cytosol inhibited specific binding of [3H]dexamethasone (P < 0.01) when mixed with cytosol prepared from either a human lymphoid cell line (HL) or rat thymus. The inhibitory activity was heat labile and trypsin sensitive. Peak inhibitory activity was found in the 150–200 kd fractions after Sephacryl G-200 ultrafiltration. Scatchard analysis of [3H]dexamethasone binding using mixed cytosol showed a diminished GR apparent binding affinity when compared to HL cytosol. Kinetic studies using mixed cytosol indicated that B95-8 cytosol did not affect the apparent dissociation rate of [3H] dexamethasone. These data demonstrate that B95-8 cells contain a competitive inhibitor that prevents binding of dexamethasone to its cognate receptor. |
| Databáze: | OpenAIRE |
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