Collective isolation of two major, close molecular weight coagulum proteins occurring in human semen before liquefaction.

Two major, close molecular weight basic coagulum proteins of freshly ejaculated human semen identifiable on reducing SDS-PAGE, have been isolated together from washed seminal coagulum. The latter was solubilized in urea, followed by reduction and carboxymethylation of disulphide bonds. By high-resolution chromatography on carboxymethy-Sephadex and Sephacryl S-300 using 8 M urea in 0.1M Tris-HCl (pH 7.4) as eluate these proteins were isolated together (purity 99%) with a yield of 10.5%. The molecular weights of the isolated proteins on SDS-PAGE were 75 and 79 kD.