title: Organ-specific binding system for beta-galactosidase in the male reproductive tract.
abstract: This study reports on the binding of beta-galactosidase obtained from different organs of the rat urogenital tract to membranes of these organs. Homologous and cross binding saturation assays indicated that: (1) high-affinity sites that recognize fructose-6-phosphate derivates (FPR) are present in spermatozoa from the rete testis, epididymal membranes and testes, although the latter may reflect binding to testicular spermatozoa; (2) the membranes of the other organs studied do not have FPR; (3) the FPR of the epididymis does not recognize enzymes purified from other organs of the reproductive tract. These results suggest that the FPR-binding system belongs to a peculiar transport route that permits maturing spermatozoa to acquire hydrolytic enzymes secreted by the epididymal epithelium. In the epididymis and seminal vesicles more than 50% of the enzymatic activity of beta-galactosidase was recovered in cytosol, suggesting that the enzyme is located mainly in the secretory fluid of these organs.
authors.affiliation: Universidad Nacional de Cuyo, Mendoza, Argentina.
authors.forename: P
authors.initials: P
authors.lastname: Grimalt
authors.forename: M A
authors.initials: MA
authors.lastname: Barbieri
authors.forename: M A
authors.initials: MA
authors.lastname: Sosa
authors.forename: F
authors.initials: F
authors.lastname: Bertini
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D004822:Epididymis / Q000378:metabolism*; D004848:Epithelium / Q000378:metabolism; D005636:Fructosephosphates / Q000378:metabolism; D007668:Kidney / Q000201:enzymology; D007700:Kinetics; D008297:Male; D009928:Organ Specificity; D011485:Protein Binding; D051381:Rats; D012669:Seminal Vesicles / Q000201:enzymology / Q000378:metabolism; D013094:Spermatozoa / Q000378:metabolism*; D013737:Testis / Q000378:metabolism*; D001616:beta-Galactosidase / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D005636:Fructosephosphates; C027618:fructose-6-phosphate; D001616:beta-Galactosidase