Isolation and characterization of two antigens from human seminal plasma

A simple method is described for the isolation of two glycopeptides from human seminal plasma. One of them cross-reacts with human spermatozoa, a fact which will help the study of antigenicity of sperm cells. The glycopeptides obtained (G1 and G2) are homogenous, as judged by disc electrophoresis, ultracentrifugation, immunodiffusion and immunoelectrophoresis. The weight average molecular weight of both glycopeptides was about 10 000 for both fractions. Differences in the amino-acid and carbohydrate composition of both glycopeptides were observed. The content of histidine was higher in one of them (G1). Only slight differences in the content of sialic acid of both glycopeptides were observed.