Acetylcholinesterase - the acyl-enzyme intermediate.

The origin of the acetyl-enzyme theory for hydrolytic reactions of acetylcholinesterase is outlined. The relationship of this theory to the inhibition of acetylcholinesterase by organophosphates is emphasized. The steady state concentration of the acetyl-enzyme was measured using acetate labeled, tritrated acetylcholine as substrate. From pH 6 to pH 9.0, 60% to 70% of the 18S enzyme is labeled at 22 degrees C in high ionic strength.