Peptide glycosylation is a covalent modification that can potentially improve the physicochemical properties of peptides. Some advantages of glycosylated peptides include: (1) increased bioavailability, (2) increased metabolic stability, (2) targeting specific tissues and organs, (3) reduction in clearance rates, (4) enhanced receptor binding, (5) facilitation of active transport across cell membranes (glucose transporters), and (6) maintaining the overall physical properties of peptides (precipitation, aggregation, thermal and kinetic denaturation).
Common Glycosylated Amino Acids
| Sugar | Amino Acid | Glycated Amino Acid | Linkage |
|---|---|---|---|
| α-D-Galactose | Serine | Ser(alpha-D-GalNAc) | |
| Tn Antigen | O-linked | ||
| α-D-Galactose | Threonine | Thr(alpha-D-GalNAc) | |
| Tn Antigen | O-linked | ||
| β-D-Galactose | Serine | Ser(beta-D-GalNAc) | O-linked |
| β-D-Galactose | Threonine | Thr(beta-D-GalNAc) | O-linked |
| β-D-Galactose | Serine | Ser(Gal-beta(1-3)GalNAc) | |
| Tf Antigen | O-linked | ||
| β-D-Galactose | Threonine | Thr (Gal-beta(1-3)GalNAc) | |
| Tf Antigen | O-linked | ||
| β-D-Glucose | Serine | Ser(beta-D-GlcNAc) | O-linked |
| β-D-Glucose | Threonine | Thr(beta-D-GlcNAc) | O-linked |
| β-D-Glucose | Asparagine | Asn(beta-D-GlcNAc) | N-linked |
| β-D-Glucose | Serine | Ser(beta-D-Glc) | O-linked |
| α-D-Mannose | Serine | Thr(alpha-D-Man) | O-linked |
| α-D-Mannose | Asparagine | Asn(alpha-D-Man) | N-linked |
| α-D-Mannose | Serine | Ser(alpha-D-Man) | O-linked |
| α-D-Mannose | Threonine | Thr(alpha-D-Man) | O-linked |
Selected Glycosylation Citations
F.-H. Guo, et al. Journal of Nuclear and Radiochemistry, 34(3), 157-165 (2012)
Glucitol-Lys(NOTA)-DPhe-Cys-Tyr-DTrp-Lys-Thr-Cys-Thr-OH
