Related Experiment Video
Updated: Jul 2, 2026

Detection of the pH-dependent Activity of Escherichia coli Chaperone HdeB In Vitro and In Vivo
Published on: October 23, 2016
Effects of pH on the activity and structure of choline oxidase from Alcaligenes species
Azadeh Hekmat1, Ali Akbar Saboury, Ali Akbar Moosavi-Movahedi
1Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran.
Abstract:
A reversible effect of pH on the ionization of amino-acid residues at the active center of choline oxidase was observed near the optimum pH (8). Inactivation of choline oxidase took place in the pH ranges 3-6 and 9-11, in which irreversible changes in the structure occur leading to the enzyme inactivation. The first order rate constants of the enzyme's inactivation at various pH values were estimated for the irreversible changes. The Arrhenius analysis revealed no significant changes in the activation enthalpy, while an increase in the activation entropy reflected an increase in the conformational freedom.
More Related Videos
14:39Cholinergic Ligand–dependent Modulation of Oxidative Phosphorylation Coupling in Digitonin-permeabilized BE(2)-C Neuroblastoma Cells
Published on: April 28, 2026
10:24Defining Hsp33's Redox-regulated Chaperone Activity and Mapping Conformational Changes on Hsp33 Using Hydrogen-deuterium Exchange Mass Spectrometry
Published on: June 7, 2018
Related Concept Videos
Indirect-Acting Cholinergic Agonists: Mechanism of Action
Reversible inhibitors like edrophonium bind to a specific part of the enzyme called the anionic catalytic site. They form noncovalent bonds, which means they are not strongly attached to the enzyme. This creates a temporary and less stable enzyme–inhibitor complex, leading to...
Direct-Acting Cholinergic Agonists: Chemistry and Structure-Activity Relationship
The direct-acting...
Indirect-Acting Cholinergic Agonists: Chemistry and Structure-Activity Relationship
Reversible inhibitors display short to medium durations of action. Short-acting agents include simple alcohols with...
Direct-Acting Cholinergic Agonists: Pharmacokinetics
Cholinesterases: Distribution and Function
Anticholinesterase Agents: Poisoning and Treatment
Irreversible agents form a strong bond with the cholinesterase enzyme, making it inactive. The breakdown of the phosphorylated enzyme is slower than the...