pH-dependent changes of ganglioside biosynthesis in neuronal cell culture.
Ganglioside biosynthesis was studied in primary cultured murine cerebellar cells after labeling with [14C]galactose. A shift in biosynthesis from "a"-series to "b"-series gangliosides was observed after lowering the pH of the culture medium from 7.4 to 6.2; this effect was fully reversible on changing back to pH 7.4. The observed regulatory effect of pH is in accordance with a recent model of ganglioside biosynthesis. Sialyltransferase II (ST II), the first enzyme for biosynthesis of "b"-series gangliosides, is more active at pH 6.2 than Gal-NAc-transferase, the first enzyme for synthesis of "a"-series gangliosides, which is more active than sialyltransferase II at pH 7.4.
Iber
H
H
Institut für Organische Chemie und Biochemie, Universität, Bonn, Bundesrepublik Deutschland.
van Echten
G
G
Klein
R A
RA
Sandhoff
K
K
D000818:Animals; D002478:Cells, Cultured; D005700:Galactosyltransferases / Q000378:metabolism; D005732:Gangliosides / Q000096:biosynthesis*; D006056:Golgi Apparatus / Q000201:enzymology; D006863:Hydrogen-Ion Concentration; D051379:Mice; D017350:N-Acetylgalactosaminyltransferases; D009474:Neurons / Q000378:metabolism*; D011817:Rabbits; D012799:Sialyltransferases / Q000378:metabolism; D000097763:Polypeptide N-acetylgalactosaminyltransferase
D005700:Galactosyltransferases; D005732:Gangliosides; D017350:N-Acetylgalactosaminyltransferases; D012799:Sialyltransferases; D000097763:Polypeptide N-acetylgalactosaminyltransferase; C063054:galactosylxylosylprotein 3-beta-galactosyltransferase; C023220:(N-acetylneuraminyl)-galactosylglucosylceramide N-acetylgalactosaminyltransferase; C043662:alpha-N-acetylneuraminate alpha-2,8-sialyltransferase