On the metabolism of GM3 ganglioside in cultured human foreskin fibroblasts

The metabolism of GM3 ganglioside in cultured human foreskin fibroblasts was investigated by labeling cultured cells with [1-3H]-galactose for 48 hours, followed by a 48 hour chase. More than 80% of the radioactivity associated with GM3 was found in the hexose portion of the carbohydrate chain, whereas approximately 12% of the radioactivity was observed in the sialic acid moiety. The hexose and sialic acid residues lost 42% and 53% of their initial radioactivity, respectively, during the chase period, indicating an active metabolism of these sugar residues of GM3 in growing cultures.