Related Experiment Video
Updated: Aug 11, 2026

High Throughput Screening of Fungal Endoglucanase Activity in Escherichia coli
Published on: August 13, 2011
Enzyme kinetics and chemical modification of alpha-1,4-glucan lyase from Gracilariopsis sp
P Nyvall1, M Pedersén, L Kenne
1Department of Botany, Stockholm University, Sweden. pi.nyvall@botan.su.se
Abstract:
The kinetic properties and active site amino acids of alpha-1,4-glucan lyase from the marine red macroalga Gracilariopsis sp. were examined. Using 1H NMR spectroscopy the alpha-1,4-glucan lyase was found to degrade alpha- and beta-maltose at different rates. The effect of pH on the kinetic constants suggested the presence of two catalytically important amino acids in the active site with pKa values of 3.5 and 6.2. The former indicated the presence of an ionised aspartate or glutamate residue in the active site. This was tested using the carboxyl specific reagent EDAC, which inhibited enzyme activity in a time dependent manner when an external nucleophile was added. No protection against the inactivation was obtained by addition of amylopectin, maltitol or 1-deoxinojirimycin. Inactivation decreased Vmax over 2.5-fold with little effect on Km which supports the direct involvement of a carboxyl group in catalysis.
More Related Videos
10:16In Vitro Enzyme Measurement to Test Pharmacological Chaperone Responsiveness in Fabry and Pompe Disease
Published on: December 20, 2017
10:26Elucidating β-1,3-Glucanase and Peroxidase Physicochemical Properties of Wheat Cell Wall Defense Mechanism Against Diuraphis noxia Infestation
Published on: July 26, 2024
Related Concept Videos
Enzyme Kinetics
Scientists typically study enzyme kinetics with a fixed amount of enzyme in the controlled environment of a test tube. When more reactant, or substrate, is...
Production of Alcohol
Production of Organic Acids