Human seminal plasma proteins: identification and preliminary characterization of a human sperm coating antigen (h-SCA) protein in physiological and pathological conditions

Abstract

The presence in the human seminal plasma (h-SP) of a protein immunologically related to the RSV-IV, protein secreted by the rat seminal vesicles (RSV), is shown. We also report that this protein (hereafter termed the h-SCA protein) binds the human sperm cell surface. This protein has been partially characterized by chromatography and gel electrophoresis, and could represent a good marker to study the human function of seminal vesicles and their androgen regulation.

Due to the availability of a sensitive immunological assay for h-SCA, we were also able to analyse its expression in normal and pathological conditions. The results of the analysis suggest that low levels of testosterone are not associated with low levels of the h-SCA. On the other hand, since other pathological conditions, such as Klinefelter’s syndrome, affect h-SCA levels more dramatically than testosterone concentrations it should be concluded that the expression of the h-SCA protein is regulated by multiple mechanisms, one of which could be testosterone dependent.