Desire_1975_C.R.Acad.Sci.Hebd.Seances.Acad.Sci.D_281_1135

In reaction mixture containing 0,1 M NaCl and acetylcholine used as substrate, the kinetics of the inhibition of bovine erythrocyte acetylcholinesterase (EC 3.1.1.7) by thioridazine hydrochloride and thiazinamium methylsulfate imply the simultaneous binding of two thioridazine or thiazinamium molecules at the free enzyme and of two thioridazine molecules at the acetylated enzyme. These observations corroborate the functional participation in the inhibition mechanism of a peripheral anionic site distinct from the anionic subsite of the active center of the enzyme.