Biosynthesis in vitro of Ii core glycosphingolipids from neolactotetraosylceramide by beta 1-3- and beta 1-6-N-acetylglucosaminyltransferases from mouse T-lymphoma

J Biol Chem. 1984 Oct 25;259(20):12557-62.

Abstract

The N-acetylglucosaminyltransferases probably involved in the biosynthesis in vitro of Ii core glycosphingolipids have been solubilized from a membrane preparation of mouse lymphoma P-1798 and partially characterized. The detergent-extracted membrane supernatant contains both beta 1-3- and beta 1-6-N-acetylglucosaminyltransferase activities that transfer [3H]GlcNAc from UDP-[3H]GlcNAc to the terminal galactose of neolactotetraosylceramide (Gal beta 1-4GlcNAc beta 1-3Gal beta 1-4Glc-ceramide; nLcOse4ceramide), to form the Ii core structures. The linkage of [3H]N-acetylglucosamine incorporated into the terminal galactose of nLcOse4Cer was determined from identification of 2,4,6-tri-O-methyl[3H]galactose and 2,3,4-tri-O-methyl[3H]galactose after hydrolysis of the permethylated enzymatic products, GlcNAc beta-[3H]Gal-GlcNAc-Gal-Glc-ceramide. In addition to the presence of beta-N-acetylglucosaminyltransferases, we have detected a galactosyltransferase activity in this soluble supernatant fraction that catalyzes the transfer of [14C]galactose from UDP-[14C]galactose to lactotriaosylceramide (GlcNAc beta 1-3Gal beta 1-4Glc-ceramide; LcOse3ceramide) to form nLcOse4ceramide, the acceptor in the N-acetylglucosaminyltransferase-catalyzed reaction.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Carbohydrate Conformation
  • Cations, Divalent
  • Cell Line
  • Cell Membrane / enzymology
  • Globosides / metabolism*
  • Glucosyltransferases / metabolism*
  • Glycosphingolipids / biosynthesis*
  • Glycosphingolipids / metabolism*
  • Kinetics
  • Lymphoma / enzymology*
  • Mice
  • N-Acetylglucosaminyltransferases*

Substances

  • Cations, Divalent
  • Globosides
  • Glycosphingolipids
  • paragloboside
  • Glucosyltransferases
  • N-Acetylglucosaminyltransferases
  • glycosphingolipid beta1-3-N-acetylglucosaminyltransferase
  • glycosphingolipid beta1-6-N-acetylglucosaminyltransferase