Enzymatic hydrolysis of disaccharide unit of collagen. Isolation of 2-O-alpha-D-glucopyranosyl-O-beta-D-galactopyranosyl-hydroxylysine glucohydrolase from rat spleens.
The hydroxylsine-linked disaccharide unit, 2-O-alpha-D-glucopyranosyl-O-beta-D-galactopyranosyl-hydroxylysine (Glc-Gal-Hyl), prepared from collagens, was hydrolyzed by a glucohydrolase present in rat spleens and lungs. This disaccharide unit was scarcely hydrolyzed by homogenates of intestines, livers, and kidneys, which had a high alpha-D-glucosidase activity for neutral glucosides. The Glc-Gal-Hyl glucohydrolase was purified from rat spleens by affinity chromatography and gel filtration to the extent that sodium dodecyl sulfate/polyacrylamide gel electrophoresis gave a single band stained by Coomassie blue G-250. This purified glucohydrolase had a pH optimum around 5.8, and the Michaelis constant was 5.9 mM when Glc-Gal-Hyl was used as a substrate. This enzyme did not hydrolyze neutral glucosides. It is concluded that this Glc-Gal-Hyl glucohydrolase is responsible for catabolism of the hydroxylsine-linked disaccharide unit derived from collagens in mammals.
D000818:Animals; D002413:Cations, Divalent; D003094:Collagen; D004187:Disaccharides / Q000032:analysis*; D005959:Glucosidases / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D051381:Rats; D013154:Spleen / Q000201:enzymology*; D013379:Substrate Specificity; D014018:Tissue Distribution
D002413:Cations, Divalent; D004187:Disaccharides; D003094:Collagen; C028287:2-O-alpha-D-glucopyranosyl-O-beta-D-galactopyranosyl-hydroxylysine glucohydrolase; D005959:Glucosidases