The effects of dimethylformamide on the interaction of the estrogen receptor with estradiol

The study of the mechanism of interaction of antiestrogens with the estrogen receptor is complicated by the limited solubility of these compounds and their nonspecific, hydrophobic interactions with proteins in estrogen receptor preparations and with the glass or plastic wall of the test tube. The organic solvent dimethylformamide increases the solubility of these compounds in aqueous solution and interferes with hydrophobic interactions with solid phases and thereby reduces their loss from the solution. For these reasons some investigators use dimethylformamide in the antiestrogen-estrogen receptor binding assay. In this study we report that dimethylformamide interferes with the estrogen receptor's binding kinetics and the estradiol-induced activation of the estrogen receptors, and inactivates the receptor.