[Interactions between desoxycholic acid glucuronides and glucuronidase (author's transl)].
It has been found that desoxycholic acid-3- (1), -12- (2) and -3,12-bis-beta-D-glucuronide (3) exert a potent allosteric effect on the beta-glucuronidase activity, which results in non-competitive inhibition of this enzyme in the pH range from 4.5 to nearly 5.5, and in its activation in the pH range from 6 to 7.4. Desoxycholic acid as well as as glycodesoxycholic acid and taurodesoxycholic acid caused a slight activation of beta-glucuronidase in the total pH range from 4.5 to 7.4. The dependence of these effects upon the pH value and the amount of the respective desoxycholic acid derivative used was demonstrated by the example of the cleavage of phenolpthalein-beta-D-glucuronide by beta-glucuronidase in the presence of the desoxycholid acid derivatives. The results obtained permit to interpret the cleavage of 1 by beta-glucuronidase. The cleavage of 1 by beta-glucuronidase is sufficiently rapid to use 1 as a CMT-selectin in the cancer multistage therapy according to Ardenne [1, 2, 5]. In contrast, no cleavage was observed in 2 and 3. To follow the cleavage of 1, a simple method has been developed which permits to determine mixtures of 1 and desoxycholic acid.
D000818:Animals; D002417:Cattle; D003840:Deoxycholic Acid / Q000494:pharmacology*; D005965:Glucuronates / Q000494:pharmacology; D005966:Glucuronidase / Q000037:antagonists & inhibitors*; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D010635:Phenolphthaleins
D005965:Glucuronates; D010635:Phenolphthaleins; D003840:Deoxycholic Acid; D005966:Glucuronidase
Weschselwirkungen zwischen Desoxycholsäureglucuroniden und Glucuronidase.