Analysis of Estramustine binding protein (EBP) in rat dorsal prostate by means of high pressure liquid chromatography.

High pressure liquid chromatography (HPLC, Toyo Soda TSK-GEL G3000 SW column) was used to analyse the properties of Estramustine binding protein (EBP) in the cytosol of rat dorsal prostate. There exist in the cytosol of rat dorsal prostate two binding components having a high affinity for Estramastine. When estimated by HPLC, the molecular weights of these Estramustine binding components are 45,000-50,000 and 25,000-30,000 daltons, respectively. The binding of 3H-Estramustine to a macromolecule with a molecular weight of 25,000-30,000 is more heat labile than binding of 3H-Estramustine to a macromolecule with a molecular weight of 45,000-50,000. The present study also demonstrates that the HPLC method offers higher resolution, smaller sample size and faster analysis than other methods used in binding studies.