title: Purification of GP-83, a glycoprotein secreted by the human epididymis and conjugated to mature spermatozoa.
abstract: Epididymal secretions are critical for mammalian spermatozoa to acquire both forward motility and an ability to recognize and penetrate oocytes. Previous studies identified two glycoproteins, GP-83 and GP-39, which were secreted by the human epididymis and may be related to maturation of sperm function. In this study, GP-83 was purified from human seminal fluid by DEAE-ion exchange, gel filtration chromatography and preparative gel elution. The isoelectric point (pI) of purified GP-83 was 6.57. Monospecific antiserum to GP-83 was induced in male New Zealand rabbits and confirmed on immunoblots. GP-83 was found in fluid, tissue and sperm extracts of corpus and cauda epididymis, but not in the caput. Immunohistochemical localization identified GP-83 in the luminal contents and in the supranuclear region and cell membrane of principal cells of the corpus and cauda epididymis. GP-83 was found on the anterior acrosome in ejaculated spermatozoa, and shifted to the equatorial region after capacitation and the acrosome reaction.
authors.affiliation: Division of Urology, Department of Surgery, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan, ROC.
authors.forename: G H
authors.initials: GH
authors.lastname: Sun
authors.forename: Y C
authors.initials: YC
authors.lastname: Lin
authors.forename: Y W
authors.initials: YW
authors.lastname: Guo
authors.forename: S Y
authors.initials: SY
authors.lastname: Chang
authors.forename: H W
authors.initials: HW
authors.lastname: Liu
mesh_terms: D020101:Acrosome Reaction / Q000187:drug effects; D000368:Aged; D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D004822:Epididymis / Q000378:metabolism*; D006023:Glycoproteins / Q000276:immunology / Q000302:isolation & purification* / Q000378:metabolism*; D006801:Humans; D007476:Ionophores / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D011817:Rabbits; D012661:Semen / Q000737:chemistry; D013079:Sperm Maturation; D013094:Spermatozoa / Q000378:metabolism*
chemical_list: D006023:Glycoproteins; D007476:Ionophores; D000001:Calcimycin