Kinetics of the Inhibition of Immobilized Acetylcholinesterase with Hg(II)

The effect of Hg(II) on the activity of the immobilized acetylcholinesterase has been studied, applying an electrochemical approach. It has been established that the lowest Hg(II) concentration, producing an inhibition was 1 10 10 mol/L and the relationship between pInh (pInh lg [Inhibitor]) and I (the difference between the value of the analytical signal in the absence and in the presence of inhibitor) has a linear character in the concentration range from 1 10 10 mol/L to 1 10 5 mol/L Hg(II). It has been proven that the inhibition of acetylcholinesterase with Hg(II) possesses a reversible and a noncompetitive character. Values of the kinetic parameters, apparent Michaelis-Menten constant Km app and inhibition constant KI have been found Km app 2 10 4 molL and KI 5.9 10 5 mol/L). The nature of occurring interactions and potential interference effects have been commented. Obtained data could be useful for the development of electrochemical sensors including immobilized acetylcholinesterase, with an application for toxic product analysis.