Sialoglycoproteins of ejaculated human spermatozoa and seminal plasma

Ejaculated human sperm were found to possess three major sialoglycoproteins with molecular weights of 30 000, 14 000 and 12 000 and one minor species of 18 000. Liquefied seminal plasma from normal donors contain two major sialoglycoproteins with molecular weights of 17 000 and 15 000 and two minor species of 70 000 and 54 000. In contrast, the liquefied sperm-free semen of vasectomized men had two major species of sialoglycoproteins of 20 000 and 18 000 daltons plus two minor species of 54 000 and 40 000.