12 Specific proline and lysine residues throughout the helical region of the collagen chains are hydroxylated to 4-hydroxyproline, 3-hydroxyproline, and hydroxylysine by prolyl 4-hydroxylase ...

Hydroxyproline is derived from proline and Hydroxylysine derived from lysine. Depending on the type of collagen, varying numbers of hydroxylysines are glycosylated (mostly having disaccharides ...