The hydroxyl group of hydroxylysine forms a chemical bond with sugars, attaching galactose monosaccharides and glucosyl-galactose disaccharides to the protein, thus contributing to collagen's unusual toughness and resiliency.
The amino acid composition of equine collagen revealed a higher amount of hydroxylysine and lysine.
These authors focused on the reduced excretion of hydroxylysine metabolites and suggest inhibition of lysyl hydroxylase as the probable pathogenetic cause.
HP is a derivative of three residues of hydroxylysine, and is present in virtually all mature tissues (tendon, vessel wall, cartilage, dentine and bone).
DD cord collagen is also reported to feature increased levels of hydroxylysine and reducible cross-links, biochemical changes associated with connective-tissue repair [ 42].
Binding of substrate analogue l-lysine causes oxidation of the NADPH cofactor, without subsequent production of hydroxylysine, effectively uncoupling the reaction.
Similarly, the galactosylated non-natural amino acid hydroxynorvalin (Gal-Hnv) peptide, which lacks aminomethylene group of hydroxylysine, failed to stimulate A8E2 hybridoma and A9.2 clone (not shown).
Lysylpyridindine is a derivative of two residues of hydroxylysine and one residue of lysine and is found principally in dentine and bone.
Hydroxy-lyslpyridindine is a derivative of three residues of hydroxylysine and is present in virtually all mature tissues (tendon, vessel wall, cartilage, dentine and bone).
Compared to collagen type I, type II chains contain a higher content of hydroxylysine as well as glucosyl and galactosyl residues which mediate the interaction with proteoglycans [ 11].
