title: Physicochemical properties of type I corticosteroid receptors from rat brain.
abstract: [3H]Aldosterone binds with high affinity to Type I corticosteroid receptors in cytosols from adrenalectomized rat forebrains. Physicochemical parameters of these receptors were determined in the presence of molybdate, which stabilized receptors and maintained them in a presumably untransformed state. The Stokes' radius of the molybdate-stabilized receptor was 8.1 nm, as determined by gel filtration on Sephacryl S-300. Its sedimentation coefficient was 9.1S in linear sucrose density gradients. The receptor is asymmetric, with an axial ratio of 8-10 and an apparent mol. wt of 303,000 dalton. The [3H]aldosterone-receptor complex is anionic and elutes from DEAE-Trisacryl in a single peak with a maximum at 160 mM KCl. Exposure to heat or salt in the absence of molybdate, conditions which transform other steroid receptors to smaller DNA-binding forms, causes marked instability of the [3H]aldosterone-receptor complex. The [3H]aldosterone-binding protein of rat forebrain, which displays the binding characteristics of a renal Type I (mineralocorticoid) receptor, is similar in size, shape and charge to the molybdate-stabilized oligomeric forms of other steroid hormone receptors.
mesh_terms: D000450:Aldosterone / Q000378:metabolism; D000818:Animals; D001921:Brain / Q000378:metabolism*; D002499:Centrifugation, Density Gradient; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D003600:Cytosol / Q000378:metabolism; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D018161:Receptors, Mineralocorticoid; D011987:Receptors, Steroid / Q000032:analysis*
chemical_list: D018161:Receptors, Mineralocorticoid; D011987:Receptors, Steroid; D000450:Aldosterone