SERINE-PROTEASE ACTIVITY IN BOAR SEMINAL-VESICLES AND ITS IMMUNOLOGICAL SIMILARITY TO SPERM ACROSIN

A mouse monoclonal antibody against boar acrosin and antiserum prepare d to highly purified acrosin in female rabbits were used to detect the antigen in various fluids and tissues of boars using an indirect immu nofluorescence technique. A strong reaction was found in fluid and epi thelial tissue of the seminal vesicles as well as in the germinal cell s in the testis. No immunoreactivity was detected in tissues of the ep ididymides and other organs of the boar. The antigens present in semin al vesicle fluid of boars were partially purified by column chromatogr aphy. It was demonstrated that two antigens differing in molecular mas s were present and both possessed protease and amidase activity. The h igher molecular mass antigen eluted from a gel filtration column in a volume identical to that of proacrosin. The same result was obtained i n polyacrylamide gel electrophoresis in sodium dodecyl sulfate (SDS-PA GE). The low molecular mass antigen was eluted from Sephadex G-75 colu mn together with natural protease inhibitors corresponding in molecula r mass to less than 20 kDa. The mobility of the antigen in SDS-PAGE wa s greater than that of chymotrypsin. It is assumed that the protease f rom seminal vesicle epithelia resembled acrosin in structure and funct ion. Acrosin may therefore not be specific for spermatozoa.