Purification of rat epididymal proteins `D' and `E', demonstration of shared immunological determinants, and identification of regional synthesis and secretion

Two acidic secretory epididymal glycoproteins, protein D of 27000 daltons and protein E of 28000 daltons, have been purified and antisera prepared against each separately. Both proteins were found to share common immunological determinants when tested by double immunodiffusion and tandem crossed immunoelectrophoresis. By selective immunoprecipitation, protein D was shown to be synthesized and secreted by all regions of the epididymis with the exception of the initial segments. In contrast, the synthesis and secretion of protein E was restricted to the corpus and proximal cauda.