Uterine, cytoplasmic estrogen binding protein. Thermal stability and ligand dissociation rate. Assay of empty and filled sites by exchange

Abstract

The thermal stability and the rate of estradiol dissociation from the cytoplasmic estrogen binding protein of rat uterus have been determined at 0, 25, 30, and 37°. Unfilled

Estrogen receptors interaction with Estracyt and degradation products, a biochemical study on a potential agent in the treatment of breast cancer

“…The rate of exchange of the compound(s) derived from Estracyt was similar to that of cold estradiol. After a few minutes (about 15 minutes) corresponding to the heating of the mixtures from 0 0 C to 18 0 C, this rate followed a saturation function consistent with those reported by Katzenellenbogen et al (10). In contrast, U 11, 100 A was rapidly exchanged during the first minutes of incubation.…”

“…At the end of incubation, the receptor binding sites were saturated either with 3H-estradiol-17 f3 only or with both 3H-estradiol-I 7 f3 and an unlabeled ligand. Exchange by 3H-estradiol-I7 f3 of these filled receptor sites was then assayed by a method similar to that described by Katzenellenbogen et al (10). One ml of each fraction was treated with 1.25 ml DCC at 18°C for 10 minutes in order to adsorb labeled and cold ligands.…”

Inhibition by various steroids on dihydrotestosterone binding to androphilic protein in human benign prostatic hypertrophy.

“…Recently, a specific steroid binding protein (PBP; prostatic binding protein) was reported by Heyns et al(1976) and Heyns and deMoor (1977), and they stated that the PBP which was prepared from acetone-dried cytosol was different from the androgen receptor of the rodent prostate. The andro- (Katzenellenbogen et al, 1973). Therefore, if one assumes that the androphilic proteins are heterogenous, it might be due, in part, to the different stability of the binding capacity to the ligand.…”

Steroid nitrates. II. Synthesis and hormonal activity of 9α,11β-dihydroxyestra-1,3,5(10)-triene 11-nitrates

“…Interaction with rat uterus estrogen receptors was studied in vitro by competition analysis [11]; binding of steroids to estrogen receptors after single doses of oil solutions of agents to female rats (in vivo) was assessed by ligand exchange [12], with assessment of the extent of binding of labeled estradiol after defined periods of time.…”