Open AccessSubstrate specificity of G M2 and G D3 synthase of Golgi vesicles derived from rat liver
Author(s) -
KLEIN Dieter,
POHLENTZ Gottfried,
SCHWARZMANN Günter,
SANDHOFF Konrad
Publication year - 1987
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1987.tb13354.x
Subject(s) - neuraminic acid , glycolipid , moiety , sialic acid , stereochemistry , residue (chemistry) , enzyme , chemistry , biochemistry , substrate (aquarium) , atp synthase , golgi apparatus , transferase , biology , endoplasmic reticulum , ecology
Several G M3 derivatives have been synthesized. Among them were lyso‐G M3 derivatives and G M3 analogues with modifications in the sialic acid moiety. They were used as glycolipid acceptors in assays for G M2 and G D3 synthase of rat liver Golgi. Analysis of the resulting enzyme activities and of the reaction products revealed different substrate specificities for G M2 and G D3 synthase although the normal glycolipid acceptor for both transferases is ganglioside G M3 . Specificity of G D3 synthase is strongly determined by the substrate's negative charge and the acyl residue in amide bond to the amino group of neuraminic acid, while G M2 synthase reacts quite indifferently to these changes in the sialic moiety of the substrate. Both enzymes seem to be sensitive to the spatial extension at the neuraminic acid's carboxylic group.