Reaction: [collagen]-(5R)-5-O-[α-D-glucosyl-(1→2)-β-D-galactosyl]-5-hydroxy-L-lysine + H2O = D-glucose + [collagen]-(55R)-5-O-(β-D-galactosyl)-5-hydroxy-L-lysine
Other name(s): 2-O-α-D-glucopyranosyl-5-O-α-D-galactopyranosylhydroxy-L-lysine glucohydrolase; protein-α-D-glucosyl-1,2-β-D-galactosyl-L-hydroxylysine glucohydrolase
Systematic name: protein-α-D-glucosyl-(1→2)-β-D-galactosyl-L-hydroxylysine glucohydrolase
Comments: The enzyme specifically hydrolyses glucose from α-D-glucosyl-(1→2)-β-D-galactosyl disaccharide units that are linked to hydroxylysine residues of collagen and collagen-like proteins. Acetylation of the ε-amino group of the glycosylated hydroxylysine abolishes activity.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 72829-45-9
References:
1. Hamazaki, H. and Hotta, K. Purification and characterization of an α-glucosidase specific for hydroxylysine-linked disaccharide of collagen. J. Biol. Chem. 254 (1979) 9682-9687. [PMID: 385589]
2. Hamazaki, H. and Hotta, K. Enzymatic hydrolysis of disaccharide unit of collagen. Isolation of 2-O-α-D-glucopyranosyl-O-β-D-galactopyranosyl-hydroxylysine glucohydrolase from rat spleens. Eur. J. Biochem. 111 (1980) 587-591. [PMID: 7460918]
3. Sternberg, M. and Shapiro, R.G. Studies on the catabolism of the hydroxylysine-linked disaccharide units of basement membranes and collagens. Isolation and characterization of a rat kidney α-glucosidase of high specificity. J. Biol. Chem. 254 (1979) 10329-10336. [PMID: 385599]
4. Hamazaki, H. and Hamazaki, M.H. Catalytic site of human protein-glucosylgalactosylhydroxylysine glucosidase: Three crucial carboxyl residues were determined by cloning and site-directed mutagenesis. Biochem. Biophys. Res. Commun. 469 (2016) 357–362. [PMID: 26682924]