Studies on a prostate specific antigen, “γ-Seminoprotein”

A relatively longer precipitin line in γ-globulin region was found in immunoelectrophoresis of seminal fluid using antiserum and this specific protein present in the seminal fluid was called as γ-seminoprotein (γ-Sm).γ-Sm was isolated and purified from seminal fluid by gel-filtration and isoelectrofocusing, and chemical property and γ-Sm level in seminal fluid were analysed.The results were;1. γ-Sm formed 5 to 6 bands in PAG electrophoresis.2. γ-Sm level in 15 seminal fluid samples was 500 to 1, 000mg/dl.3. Primary structure of γ-Sm was found to be consisted with 237 amino acid residues and possessed N-acetylglucosaminyl-asparagine linkage at 45 position.4. γ-Sm is one of serine proteases possessing active serine at 189 position from N-terminal.5. γ-Sm is an useful marker of seminal fluid in forensic medicine and also as a tumor marker for prostate cancer.6. γ-Sm was observed to be localized in prostatic cells by PAP method and the substance was demonstrated in perinuclear space, rough endoplasmic reticulum, Golgi apparatus, secretory granules and lysosome of prostatic epithelial cell by immunoelectron microscopic method.