O-linked-serine-threonine-glycosides-N-linked-asparagine-glycosides Published January 22, 2019 at 307 × 233 in Peptide Synthesis Glycosylation as Biomarkers Peptide Synthesis Service-Glycosylation Glycosylation is the most abundant polypeptide chain modification in nature. Glycoproteins are a significant class of current therapeutic targets and clinical biomarkers.