title: Activity of UDP-GlcNAc:GlcNAc beta 1-->6(GlcNAc beta 1-->2) Man alpha 1-->R[GlcNAc to Man] beta 1-->4N-acetylglucosaminyltransferase VI (GnT VI) from the ovaries of Oryzias latipes (Medaka fish).
abstract: UDP-GlcNAc:GlcNAc beta 1-->(GlcNAc beta 1-->2)Man alpha 1-R[GlcNAc to Man] beta 1-->4N-acetylglucosaminyltransferase VI (GnT VI) activity was shown to be present in crude homogenates of Medaka fish (Oryzias latipes) ovaries using UDP-[14C]GlcNAc and synthetic GlcNAc beta 1-->6 (GlcNAc beta 1-->2)Man alpha 1-->6Glc beta 1-->octyl as substrates. Characterization of this activity showed a pH optimum at about pH 7.0 and an absolute requirement for divalent cations. The optimum concentration of Mn2+ was at about 25 mM. This finding is the first report on GnT VI activity in fish; the enzyme has previously been described only in avian tissues.
authors.affiliation: Department of Biophysics and Biochemistry, Graduate School of Science, University of Tokyo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Taguchi
authors.forename: K
authors.initials: K
authors.lastname: Kitajima
authors.forename: S
authors.initials: S
authors.lastname: Inoue
authors.forename: Y
authors.initials: Y
authors.lastname: Inoue
authors.forename: J M
authors.initials: JM
authors.lastname: Yang
authors.forename: H
authors.initials: H
authors.lastname: Schachter
authors.forename: I
authors.initials: I
authors.lastname: Brockhausen
mesh_terms: D000818:Animals; D002240:Carbohydrate Sequence; D002413:Cations, Divalent / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D005260:Female; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008345:Manganese / Q000378:metabolism / Q000494:pharmacology; D008969:Molecular Sequence Data; D017351:N-Acetylglucosaminyltransferases / Q000187:drug effects / Q000378:metabolism*; D009990:Oryzias; D010053:Ovary / Q000201:enzymology*; D013379:Substrate Specificity
chemical_list: D002413:Cations, Divalent; D008345:Manganese; D017351:N-Acetylglucosaminyltransferases; C066287:UDP-GlcNAc-Gb(5)Cer beta1-6N-acetylglucosaminyltransferase