Abstract
The abilities of four β-glucuronidase preparations, Helix pomatia, Patella vulgata, Escherichia coli, and beef liver, to hydrolyze bile acid glucuronides were determined as a function of pH and time. The substrates included 3-glucuronides of free, glycine- and taurine-conjugated lithocholate, chenodeoxycholate, deoxycholate, and cholate. In general, the optimal pH for β-glucuronidase-catalyzed hydrolysis of these substrates was more acidic in the case of nonbacterial β-glucuronidase preparations than in the case of the E. coli enzyme. It was also dependent upon the number of hydroxyl groups on the steroid nucleus, but not upon the side chain structure. No evidence was obtained of any overall superiority of any one enzyme preparation in hydrolyzing bile acid glucuronides.
