Demonstration of an anionic acrosin inhibitor in spermatozoa epididymal fluid and seminal plasma of the boar.
A new anionic acrosin inhibitor was found in an acidic extract of boar spermatozoa. The protein was purified by hydrophobic and ion exchange chromatography. According to gel filtration and SDS-electrophoresis the inhibitor preparation shows a molecular mass of Mr approximately 6000-7000 daltons. The isoelectric point is close to pH 4.5. It is an effective inhibitor of boar acrosin and bovine trypsin, but it does not inhibit porcine plasmin and pancreatic kallikrein or bovine chymotrypsin. An inhibitor with identical properties was found in high concentration (97% of the total acrosin inhibiting activity) in the fluid of cauda epididymis and also as a minor acrosin inhibiting component (2% of total acrosin inhibiting activity) in seminal plasma. The results indicate that binding of the inhibitor to spermatozoa may have taken place in the epididymis.
D000176:Acrosin / Q000037:antagonists & inhibitors*; D000818:Animals; D000838:Anions; D001826:Body Fluids / Q000378:metabolism; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D004822:Epididymis / Q000378:metabolism*; D007525:Isoelectric Focusing; D008297:Male; D008970:Molecular Weight; D011480:Protease Inhibitors; D011485:Protein Binding; D012661:Semen / Q000378:metabolism*; D013094:Spermatozoa / Q000378:metabolism*; D013552:Swine; D014361:Trypsin Inhibitors / Q000032:analysis
D000838:Anions; D011480:Protease Inhibitors; D014361:Trypsin Inhibitors; D000176:Acrosin