title: Glycosidic bond rearrangements in isomeric xylobioses by yeast xylan-degrading enzymes.
abstract: The cells of Cryptococcus albidus induced for xylan-degrading enzymes are capable of transforming 1,2-beta-xylobiose and 1,3-beta-xylobiose into 1,4-beta-xylobiose, the natural inducer. The conversion involves transglycosylation and hydrolysis catalyzed by beta-xylosidase and beta-xylanase. A probable intermediate of the conversion of 1,2-beta-xylobiose was isolated and identified as a trisaccharide, 4-O-beta-xylopyranosyl-2-O-beta-xylopyranosyl-D-xylopyran ose. The trisaccharide is cleaved by purified endo-1,4-beta-xylanase of C. albidus mainly at the 1,2-beta-linkage yielding xylose and 1,4-beta-xylobiose.
mesh_terms: D002236:Carbohydrate Conformation; D003454:Cryptococcus / Q000201:enzymology*; D004187:Disaccharides / Q000378:metabolism*; D043364:Endo-1,4-beta Xylanases; D006026:Glycoside Hydrolases / Q000378:metabolism; D006027:Glycosides / Q000378:metabolism*; D007536:Isomerism; D011134:Polysaccharides / Q000378:metabolism*; D014990:Xylans / Q000378:metabolism*; D014994:Xylose / Q000378:metabolism; D014995:Xylosidases / Q000378:metabolism
chemical_list: D004187:Disaccharides; D006027:Glycosides; D011134:Polysaccharides; D014990:Xylans; D014994:Xylose; D006026:Glycoside Hydrolases; D014995:Xylosidases; C026579:exo-1,4-beta-D-xylosidase; D043364:Endo-1,4-beta Xylanases; C004173:xylobiose