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

Abstract

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.

First report on purification of the predominant acidic coagulum protein of human semen prior to liquefaction

“…3) is in accordance with the observation of Kusamran & Surakarnkul ( 1983) that the basic proteins occur at higher concentration in human seminal coagulum. The column-bound prominent basic proteins could be recovered by elution with different concentrations of NaCl (60 m~-7 5 and 79 kD; 125 m~-5 7 kD) for their subsequent purification (Mandal & Bhattacharyya, 1994a, 1994b. Figures 1 (Lane 1 and 2) and 3 show that the 162-kD protein is the predominant-acidic coagulum protein of highest molecular size.…”

“…The human seminal coagulum is a protein complex aggregated through non-covalent bonds as the washed seminal clot remains unaltered for several hours at 37 "C (Mandal & Bhattacharyya, 1990 but the same dissolves immediately in buffer containing guanidine hydrochloride (Lilja & Laurell, 1985) or urea (Mandal & Bhattacharyya, 1994a, 1994b. A number of unit proteins with a wide range of molecular sizes (162-15 kD) are recognizable in the washed human seminal coagulum on reducing SDS-PAGE (Lilja & Laurell, 1985;McGee & Herr, 1987;Mandal & Bhattacharyya, 1992).…”