Comparative abilities and optimal conditions for beta-glycosidase enzymes to hydrolyse the glucuronide, glucoside, and N-acetylglucosaminide conjugates of bile acids.
Enzymatic hydrolyses were described for three variants of glycosidic conjugated bile acids with one beta-glucuronidase (Helix pomatia), three beta-glucosidase (almonds, sweet almonds, and Escherichia coli), and four beta-N-acetylglucosaminidase (jack beans, bovine kidney, human placenta, and Diplococcus pneumoniae) preparations. The substrates include the beta-glucuronide, beta-glucoside, and beta-N-acetylglucosaminide conjugates of bile acids related to hyodeoxycholic, murideoxycholic, chenodeoxycholic, and ursodeoxycholic acids possessing a sugar moiety at position C-3, C-6 or C-7. The comparative abilities and optimal conditions for the beta-glycosidases to catalyze the hydrolyses of the substrates were clarified by changing pHs and incubation times. Hydrolysis rates of the bile acid glycosides with beta-glycosidase treatments were influenced by both the source of the enzyme preparations and the conjugated position of a sugar moiety in the substrates, and the 3-glucoside and 3-N-acetylglucosaminide conjugates were usually hydrolyzed more efficiently than their corresponding 6- and 7-analogs. Escherichia coli and jack bean enzymes were chosen to hydrolyse the glucosidic and N-acetylglucosaminidic conjugated bile acids, respectively.
Momose
T
T
College of Engineering, Nihon University, Fukushima, Japan.
Maruyama
J
J
Iida
T
T
Goto
J
J
Nambara
T
T
D000117:Acetylglucosamine / Q000031:analogs & derivatives* / Q000378:metabolism; D001647:Bile Acids and Salts / Q000737:chemistry / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D005960:Glucosides / Q000378:metabolism*; D005965:Glucuronates / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D013056:Spectrophotometry, Ultraviolet; D001617:beta-Glucosidase / Q000378:metabolism*
D001647:Bile Acids and Salts; D005960:Glucosides; D005965:Glucuronates; D001617:beta-Glucosidase; D000117:Acetylglucosamine