title: Stabilization of 8S progesterone receptor from human prostate in the presence of molybdate ion.
abstract: In the presence of 10 mM molybdate ion, we are able to detect the appearance of a [6,7-3H]-17,21-dimethyl-19-nor-4,9-pregnadiene-3,20-dione-([3H]R5020) binding moiety in human prostatic cytosol which sedimented at approximately 8S in a glycerol density gradient. The specifically bound [3H]-R5020 was displaced by progesterone, tiramcinolone acetonide, and R5020 but not by cortisol, dihydrotestosterone, 17 beta-estradiol, or diethylstilbestrol. Specific binding of [3H]R5020 in the presence of molybdate ion was shown to saturate at 7 x 10(-10) M (n = 64 fmol/mg of protein). The optimum concentration of molybdate ion for enhancing specific binding of [3H]-R5020 was determined to be between 7 and 20 mM. Molybdate ion was also effective in stabilizing the 8S R5020-binding moiety in a preincubation for 16 hr at 0 degrees in the absence of added steroid.
mesh_terms: D001667:Binding, Competitive; D002499:Centrifugation, Density Gradient; D003600:Cytosol / Q000032:analysis; D006801:Humans; D008297:Male; D008982:Molybdenum / Q000378:metabolism*; D011397:Promegestone / Q000378:metabolism; D011467:Prostate / Q000378:metabolism* / Q000648:ultrastructure; D011980:Receptors, Progesterone / Q000378:metabolism*
chemical_list: D011980:Receptors, Progesterone; D008982:Molybdenum; D011397:Promegestone