Protein characterization of multi-fraction split-ejaculates. Some physicochemical properties of prostatic and vesicular proteins.

A simple method of splitting ejaculates into 10-15 consecutive fractions proved to be valuable for separating proteins of prostatic and vesicular origin. After blocking autoproteolysis by EDTA and PMSF the fractions of four multi-fraction split-ejaculates were studied by one-dimensional electrophoresis in the presence of SDS (slab SDS-PAGE). Two split-ejaculates were further analyzed by isoelectrofocusing (PAGIEF). The zinc and fructose distributions were determined for one of the samples. The results show i) that the initial third, roughly, of the ejaculate contains proteins previously characterized as of prostatic origin (Balerna et al., 1982 a); ii) that these initial fractions have a high zinc/fructose ratio; iii) that the vesicular portion of the ejaculate is characterized by low zinc/fructose ratio and by fairly high amounts of low molecular-weight proteins and; iiii) that the proteins of the initial (prostatic) part of the ejaculate are mainly acidic-neutral whereas some proteins of the final (vesicular part) have a strong cationic character.