These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Hydrolysis of 4-nitrophenyl acetate catalyzed by carbonic anhydrase III from bovine skeletal muscle.
    Author: Tu CK, Thomas HG, Wynns GC, Silverman DN.
    Journal: J Biol Chem; 1986 Aug 05; 261(22):10100-3. PubMed ID: 3090030.
    Abstract:
    We report three experiments which show that the hydrolysis of 4-nitrophenyl acetate catalyzed by carbonic anhydrase III from bovine skeletal muscle occurs at a site on the enzyme different than the active site for CO2 hydration. This is in contrast with isozymes I and II of carbonic anhydrase for which the sites of 4-nitrophenyl acetate hydrolysis and CO2 hydration are the same. The pH profile of kcat/Km for hydrolysis of 4-nitrophenyl acetate was roughly described by the ionization of a group with pKa 6.5, whereas kcat/Km for CO2 hydration catalyzed by isozyme III was independent of pH in the range of pH 6.0-8.5. The apoenzyme of carbonic anhydrase III, which is inactive in the catalytic hydration of CO2, was found to be as active in the hydrolysis of 4-nitrophenyl acetate as native isozyme III. Concentrations of N-3 and OCN- and the sulfonamides methazolamide and chlorzolamide which inhibited CO2 hydration did not affect catalytic hydrolysis of 4-nitrophenyl acetate by carbonic anhydrase III.
    [Abstract] [Full Text] [Related] [New Search]