Cholesterol-containing lactose derived neoglycolipids serve as acceptors for sialyltransferases from rat liver Golgi vesicles.

The cholesterol-containing lactose derived neoglycolipids beta-Lactosylcholesterol, Cholesteryl-beta-lactosylpropane-1,3-diol, 3-Cholesteryl-1-beta-lactosylglycerol, 2-Cholesteryl-1-beta-lactosylglycerol, 2,3-Dicholesteryl-1-beta-lactosylglycerol, 1-Deoxy-1-cholesterylethanolaminolactitol, 1-Deoxy-1-cholesteryl (N-acetyl)-ethanolaminolactitol, 1-Deoxy-1-cholesterylphosphoethanolaminolactitol, and 1-Deoxy-1-cholesterylphospho (N-acetyl)-ethanolaminolactitol were synthesized and used as acceptors for sialytransferases from rat liver to Golgi vesicles. Relative activities with the neoglycolipids as acceptors varied from 28 to 163% compared to those obtained with the authentic acceptor lactosylceramide. Product identification by thin layer chromatography and fast atom bombardment mass spectrometry showed that the neoglycolipids yielded mono- and disialylated products. The results of competition experiments suggested that lactosylceramide and the neoglycolipids were sialylated by the same enzymes.