A four-step, inexpensive protocol for large-scale purification of goat uterine estrogen receptor.

A relatively inexpensive yet highly efficient and extremely rapid procedure has been developed for the isolation and purification of estrogen receptor from the goat uterine cytosol. Greater than 1 mg of purified receptor protein could be obtained from 75 g of uterine tissue within a period of < 24 h, following this protocol. The procedure does not require the use of an ultracentrifuge, a cold room, or a column chromatography setup. The entire isolation procedure, which involves adsorption to and selective elution from different chromatography matrices, is carried out at the laboratory bench using beakers kept in an ice bath. Antibodies raised against this receptor cross-react with the goat uterine estrogen receptor activation factor, a DNA binding protein having no capacity to bind estradiol but which dimerizes with the nonactivated estrogen receptor, an estrogen receptor incapable of binding to DNA on its own.