Abstract

The activity of acetylcholinesterase (AChE) in acetylcholine receptor (AChR)-enriched membrane vesicles isolated from electric organ of Torpedo californica exhibited a biphasic response to ethanol action. Below an ethanol concentration of 35 m M, AChE activity increased with increasing concentration of ethanol. At ethanol concentrations greater than 35 m M, the activity was found to decrease montonically. In contrast, ethanol (35–400 m M) increased the activity of soluble AChE. This biphasic behavior was consistent with the proposed important role of ethanol-membrane interaction. Microcalorimetric measurements revealed that the enthalpy change in acetylcholine (ACh) hydrolysis reaction was 586 J/mol in association with membrane-bound AChE in AChR-enriched membrane vesicles, as compared to −544 J/mol with the isolated soluble AChE. This discrepancy was attributed to the presence of membranes. Unlike its action on the enzyme activity, ethanol did not affect the enthalpy change in ACh hydrolysis reaction catalysed by either membrane-bound or soluble AChE. Comparison of results on activity and heat measurements suggested that the interaction of ethanol with membrane vesicles was nonspecific with no ethanol-induced membrane structural or conformational change.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.