title: Peptidase activities in human semen.
abstract: Enkephalins are one of the opioids present in human semen and to date their function in this tissue remains unknown. The present work studies enkephalin-degrading enzyme activities, puromycin-sensitive alanyl aminopeptidase (AAP-S), puromycin-insensitive alanyl aminopeptidase N (Ap N) and neprilysin (NEP) in human seminal fractions. AAP-S activity was not detected in any fractions, whereas Ap N appeared in soluble and particulate sperm fractions in seminal fluid and in prostasome fraction. With regard to NEP activity, this was exclusively located in prostasome membranes. The high activity values observed in the prostasome fraction suggested that these peptidases and their substrates could be involved in seminal physiology.
authors.affiliation: Department of Physiology, Medical School, University of the Basque Country, P.O. Box 699, Bilbao, Spain. ofpfeosd@lg.ehu.es
authors.forename: David
authors.initials: D
authors.lastname: Fernández
authors.forename: Asier
authors.initials: A
authors.lastname: Valdivia
authors.forename: Jon
authors.initials: J
authors.lastname: Irazusta
authors.forename: Carmen
authors.initials: C
authors.lastname: Ochoa
authors.forename: Luis
authors.initials: L
authors.lastname: Casis
mesh_terms: D000818:Animals; D018826:CD13 Antigens / Q000037:antagonists & inhibitors / Q000378:metabolism; D006801:Humans; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008297:Male; D015260:Neprilysin / Q000037:antagonists & inhibitors / Q000378:metabolism; D010447:Peptide Hydrolases / Q000378:metabolism*; D011480:Protease Inhibitors / Q000494:pharmacology; D011691:Puromycin / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012661:Semen / Q000201:enzymology*; D013438:Sulfhydryl Compounds / Q000494:pharmacology; D014018:Tissue Distribution
chemical_list: D011480:Protease Inhibitors; D013438:Sulfhydryl Compounds; D011691:Puromycin; D007770:L-Lactate Dehydrogenase; D010447:Peptide Hydrolases; D018826:CD13 Antigens; D015260:Neprilysin