ISSN:
1471-4159
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
Abstract— The pathway of biosynthesis of N-acetylgalactosamine-containing gangliosides in mouse neuroblastoma has been studied using NB41A cells grown in monolayer tissue culture. Cell-free enzyme preparations catalyzed the transfer of NeuNAc from CMP-NeuNAc to lactosylceramide (GL-2a), to form GM3. Asialo-GM2 was neither an acceptor nor a competitive inhibitor of the sialyltransferase (CMP-NeuNAc: GL-2a N-acetylneuraminyltransferase, EC 2.4.99.-) under a variety of experimental conditions. Enzyme preparations also contained an N-acetylgalactosaminyltransferase (UDP-GalNAc. GM3N-acetylgalactosaminyltransferase, EC 2.4.1.-) which catalyzed the conversion of GM3 to GM2. No significant transfer of N-acetylgalactosamine to GL-2a could be demonstrated. The results of the glycosyltransferase assays support the concept that the first NeuNAc of brain gangliosides is introduced into GL-2a. The present data suggests that the occurrence of asialo-GM2 in NB41A cells under some culture conditions is a consequence of the catabolism of higher gangliosides.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1471-4159.1976.tb10400.x
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