BIOSYNTHESIS OF GLYCOPROTEINS AND ITS RELATIONSHIP TO HETEROGENEITY

In glycoproteins the amino-acid sequence of the polypeptide chain is determined by the usual template mechanism. The stepwise addition of sugar residues to the growing carbohydrate chain, however, is directed by highly specific but not unfailing transferases. This probably accounts for the heterogeneity of carbohydrate groups within a single species of glycoprotein molecules. © 1969 Nature Publishing Group.