Proteoglycans (PGs) are a family of molecules that undergo extensive post-translational
modifications that include addition of glycosaminoglycan (GAG) chains as well as N-and O-
linked oligosaccharides to the protein core. PG composition and structure have been
reported to alter with age. To test whether the post-translational modifications to PGs can
serve asin vitro surrogate end point markers for chronological age, the extent of GAG
modifications was determined for PGs derived from normal human bone cells of 14 donors …