[Existence of UDP galactose: galactosyltransferase activity at the external surface of cultured neurons].
The existence of UDP-galactose:galactosyltransferase activities at the external surface of cultured neurons from chick embryo hemispheres, was demonstrated. [14C]-galactose was transferred upon cellular substrates present on the neuronal surface and upon exogenous substrates (ovomucoïd) bound to Sepharose beads. The activity of ectogalactosyltransferase was not due to a leakage of intracellular enzymes into the incubation medium nor to an intracellular enzymatic activity utilizing [14C]-galactose obtained from the hydrolysis of UDP-[14C]-galactose. Kinetics of these ectogalactosyltransferases were analysed. The results support the hypothesis of a communication and/or interaction among the nerve cell surfaces via glycoconjugates or their biosynthetic enzymes.
D000818:Animals; D001921:Brain / Q000196:embryology / Q000201:enzymology; D002478:Cells, Cultured; D002642:Chick Embryo; D005700:Galactosyltransferases / Q000378:metabolism*; D007700:Kinetics; D009474:Neurons / Q000201:enzymology*; D013379:Substrate Specificity; D013499:Surface Properties; D014531:Uridine Diphosphate Galactose / Q000378:metabolism*; D014539:Uridine Diphosphate Sugars / Q000378:metabolism*
D014539:Uridine Diphosphate Sugars; D014531:Uridine Diphosphate Galactose; D005700:Galactosyltransferases
Existence d'une activité UDP-galactose: galactosyltransférase à la surface externe de neurones en culture.