Carbohydrate-amino acid linkages types

Structures and Types of Carbohydrate-Amino Acid Linkages. 4... 

In this Section, the nature of the linkages between the protein chain and the carbohydrate moieties in glycoproteins will be considered, and some indication of their occurrence will be given. It will become clear that, in a number of examples, a given polypeptide chain is glycosidically substituted at more than one point. Sometimes, the amino acid residue at two such points is of a different type, so that more than one type of carbohydrate-peptide bond occurs in the same protein, It is likely that more examples of this kind of structure will be found as more features of the constitution of glycoproteins involved in membranes and connective tissue are determined. 

It is possible that, in this type of glycoprotein, the amino acid sequence of the peptide (specifically, the unusual tripeptide of proline) is involved in signaling the formation of the O-glycosyl type of bridge linkage between the carbohydrate and the protein. Further examples... 

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