Hydroxylysine glycosides

Hydroxylysine glycosides occur at the Y-position and may play a role in determining fibril diameter. The side chains of these amino acids project outward from the center of the triple helix, permitting hydrophobic and ionic interactions between tropocollagen molecules. These interactions determine the manner in which individual tropocollagen molecules aggregate to form microfibrils initially, then larger fibrils, and eventually fibers. 

The pattern of excretion of the collagen metabolites L-hydroxyproline, L-hydroxylysine, and L-hydroxylysine glycosides in urine by patients with Paget s disease of the bone, and carcinoma with bone metastases, is reported to be a... 

The amounts of different hydroxylysine-containing compounds present in the urine of patients up to forty years of age have been examined. The urinary excretion of hydroxylysine glycosides, free hydroxylysine, and peptide-bound hydroxylysine increased from the age of six months to puberty. 

Fig. 5. Synthesis of 1,2-trans glycosides using a participating group at C-2 for example, synthesis of glycosylated hydroxylysine derivative (p-D-Gal-( 1 >0)-IIyl) using (a) insoluble promoter-silver silicate (56) (b) soluble promoter-silver trifluo-romethanesulfonate (57).

O-glycosidic, between the reducing end monosaccharide and the side chain hydroxy group of most commonly serine and threonine but also hydroxyproline, hydroxylysine, and tyrosine (O-glycans), and... 

A (3-0-glycosidic linkage between galactose and a hydroxylysine residue of the protein (Gal-Hyl). Linkage found in collagen. 

The oligosaccharide is involved at its reducing end in a glycosidic bond with one of the hydroxylated side chain residues of the polypeptide. They are the ones derived from L-serine 13.11, L-threonine 13.12, L-hydroxylysine 13.13, and... 

Asn-X-Thr/Ser, is involved in the carbohydrate-peptide bond, and second, O-glycosidic linkage of galactosamine, where serine and/or threonine, as well as hydroxylysine in no apparent signal sequence, are involved in the carbohydrate-peptide bond. The constituents of carbohydrate chains include galactose, mannose, fucose, A -acetylglucosamine, A-acetylgalactosamine, and sialic acid. 

Most of the hydroxylysine residues of basement membranes are linked to the disaccharide 2-O-a-D-glucosyl-D-galactose by -glycosidic bonds... 

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