Effect of phosphoesters on catalytic activity of acetylcholinesterase

Abstract

Reversible and irreversible inhibition of acetylcholine esterase has always been an active area of interest and research, having both pharmacological and environmental relevance. Organophosphates like paraoxon possess acute toxicity towards Acetylcholinesterase by irreversibly inhibiting the enzyme. In this particular study, we have investigated the effect of various phosphoesters, mainly nucleotides, on Acetylcholinesterase's catalytic functionality. What we have observed is the differential inhibitory action of various nucleotides towards the enzyme. In presence of adenosine monophosphate, the catalytic activity almost remains the same while in the presence of ADP, ATP and cAMP activity declines. Also, we have studied the catalytic activity of AChE vesicles in the presence of all of the nucleotides. The inhibitory effects differ from the native enzyme. In vesicle bound state, cAMP does not inhibit Acetylcholinesterase much as compared to unbound state. The secondary structure of proteins remains intact in the presence of all nucleotides, as indicated by the alpha- helix and beta-sheet contents of AChE. Phosphoesters that are more hydrophobic have shown more effects towards decreasing the activity of Acetylcholinesterase.