title: Purification and properties of beta-N-acetyl-D-hexosaminidase from boar seminal plasma.
abstract: beta-N-Acetyl-D-hexosaminidase has been purified ca. 190-fold to homogeneity from boar seminal plasma. It catalyzed the hydrolysis of the p-nitrophenyl-N-acetyl derivatives of both beta-D-glucosaminide and beta-D-galactosaminide but was inactive with the o- or p-nitrophenyl glycosides of other monosaccharides. Its pH optimum was 4.5 and its KM was 1.5 mM with p-nitrophenyl-N-acetyl-beta-D-glucosamide as substrate. The enzyme was inhibited by mercuribenzoate compounds but not by iodoacetamide, 2,2'-dipyridyl disulfide, methylmethane thiosulfonate, nor N-ethylmaleimide. The active enzyme had mol. wt ca. 250,000 by Sephacryl S-300 chromatography. SDS electrophoresis showed single bands corresponding to subunit mol. wts ca. 62,000 and 107,000 depending on whether the enzyme had been denatured in the presence of 2-mercaptoethanol or not. These data suggest that the enzyme is a tetramer of identical subunits, pairs of which are held together by disulfide bonds.
authors.forename: H H
authors.initials: HH
authors.lastname: Daron
authors.forename: J L
authors.initials: JL
authors.lastname: Aull
mesh_terms: D000818:Animals; D002384:Catalysis; D004591:Electrophoresis, Polyacrylamide Gel; D006596:Hexosaminidases / Q000302:isolation & purification* / Q000378:metabolism; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D008297:Male; D008970:Molecular Weight; D011489:Protein Denaturation; D011506:Proteins / Q000378:metabolism; D012661:Semen / Q000201:enzymology*; D013439:Sulfhydryl Reagents; D013552:Swine; D001619:beta-N-Acetylhexosaminidases
chemical_list: D011506:Proteins; D013439:Sulfhydryl Reagents; D006596:Hexosaminidases; D001619:beta-N-Acetylhexosaminidases