A molecular chromatographic approach to study the effects of OH center dot and NO on acetylcholinesterase activity

作者：Ibrahim Firas; Andre Claire; Aljhni Rania; Gharbi Tijani; Guillaume Yves Claude^*

来源：Journal of Molecular Catalysis B: Enzymatic , 2013, 94: 136-140.

DOI：10.1016/j.molcatb.2013.04.014

• Acetylcholinesterase
• NO
• OH center dot
• Liquid chromatography
• Thermodynamics

Acetylcholinesterase (AChE) is a serine protease that hydrolyzes the neurotransmitter acetylcholine. Here, the effects of hydroxyl radical (OH center dot) and nitric oxide (NO) on AChE activity were studied using a biochromatographic process. The enzyme was immobilized on an ethylenediamine (EDA) monolithic convective interaction media (CIM) disk. The AChE enzymatic mechanism was demonstrated from the chromatographic peak shape. A decrease in AChE activity was observed for each concentration of NO, while OH center dot radical formation led to an increase in the rate of enzymatic catalysis. Michaelis-Menten and Lineweaver-Burk plots were obtained in the presence or absence of the free radicals and their effects on K-m and V-max were evaluated. Our results indicated classical deactivation/activation kinetics without significant influence on the rate of substrate binding. The variation in transition state energies (Delta Delta G(ES)) induced by the free radicals indicated that a conformational change was occurring in the active site, while changes in the binding site were negligible. These results clearly demonstrate the direct role of OH center dot and NO on AChE activity and confirm the role they may play in Alzheimer's disease.

• 出版日期2013-10