The Antigenic Mucin‐Like Glycoproteins of Human Seminal Plasma*

ABSTRACT: Immunodiffusion, immunoelectrophoresis, SDS‐polyacrylamide gel electrophoresis, polyacrylamide gel electrophoresis, ultracentrifugation analysis, and gel permeation chromatography in chaotropic and detergent mediums showed that the human seminal plasma obtained and stored in the usual way is mainly composed by heterodispersed glycoproteins of low molecular weight.The glycoprotein components of the human seminal plasma which do not interact specifically with concanavalin A (con A) were separated by column chromatography on Con A‐Sepharose according to nonspecificion exchange and hydrophobic interactions with the protein.The carbohydrate composition of the glycoproteins and the existence of the N‐acetylgalactosaminylserine (or threonine) linkage, as well as their aggregation properties show that they are mucin‐type glycoproteins.They resulted “immunologically pure’ although the carbohydrate chains show the structural heterodispersion usually found in mucins.The glycoproteins have a common structural pattern for the terminal nonreducing, determinant‐bearing sequences oftheir oligosaccharide chains which, together with the low molecular weights and the known fact that mucus secretions of normal cells contain only one or two types of glycoproteins, suggest that they are fragments produced by endogenous proteolytic degradation of a native mucin.