Glycosyltransferases
Glycosyltransferases form glycosidic bonds between a carbohydrate chain and a protein, by glycosylation, often a membrane protein in order to form the glycocalyx. The type of Glycosyltransferase that is coded for in a cell determines the structure of the glycocalyx and therefore the type of antigens which are presented on the outside of the cell. an example of this is Blood types.