Effects of site-directed mutagenesis on the N-glycosylation sites of human lecithin: cholesterol acyltransferase

The specific activity of four N-glycosylation sites in human lecithin rises by 50% when the carbohydrate is removed by neuraminidase. Chinese hamster ovary cells secrete a certain amount of cholesterol aceyltransferase, which is not influenced by the glucosidase inhibitors. Protein glycosylation occurs in two steps. The coarse endoplasmic reticulum gives rise to the core sugars of the glycoprotein from dolichol donors. Glucosylation is accentuated by the movement of the glycoproteins from the endoplasmic reticulum to the Golgi complex. The structure reveals signals which guide the glycoproteins in various directions.