Affinity chromatography of estrogen receptors on diethylstilbestrol-agarose

Diethylstilbestrol was coupled to epoxy-activated agarose yielding an affinity resin which is highly efficient for the isolation of estrogen receptors. This resin, diethylstilbestrol-agarose (DES-agarose), bound two proteins (Mr = 50,000 and 65,000) from rabbit uterine cytosol that show a specific interaction with estradiol. A two step procedure--adsorption on DES-agarose followed by a selective elution with p-sec-amylphenol and NaSCN, yielded highly purified estrogen receptors which can be used in the studies of estradiol-receptor interactions with other cell constituents.