Acceptor activity of subcellular membranes for two terminal sugars, galactose and sialic acid

The acceptor activities of subcellular membrane preparations for the terminal sugars, galactose and sialic acid, were compared using a Golgi fraction purified from rat liver as an exogenous emzymes source for sugar transfer. Data are presented which strongly suggest that completion of carbohydrate chains of membrane glycoproteins and glycolipids occurs in the Golgi apparatus. Significant differences of acceptability of galactose and sialic acid were found between plasma membranes of rat liver and hepatoma cells (AH-130), indicating "incompleteness" of sugar chains in the latter.