1. Acetylcholinesterase (1) Sites of location  Cholinergic neurons  Cholinergic synapses  Neuromuscular junction  Red blood cells Substrates  Acetylcholine is the best substrate  Methacholine is a substrate  Hydrolyzes ACh at greater velocity than choline esters with acyl groups larger than acetate or proprionate

2. Acetylcholinesterase (2) Esters that are not substrates  Bethanechol  Carbachol  Succinylcholine Its inhibition produces synergistic interaction with methacholine and additive actions with bethanechol and carbachol Drugs that block its hydrolysis of esters are called cholinesterase inhibitors

3. Drug Interactions of Choline Esters and Inhibitors of Acetylcholinesterase - Synergism versus Additivity Methacholine Carbachol Bethanechol

4. Butyrylcholinesterase (Plasma esterase, pseudocholinesterase, serum esterase, BuChE, PseudoChE)

5. Butyrylcholinesterase (1) Sites of location  Plasma, liver, glial cells, other tissues Substrates  Butyrylcholine is the best  Acetylcholine  Succinylcholine  Procaine

6. Butyrylcholinesterase (2) Esters that are not substrates  Methacholine, bethanechol, and carbachol Is inhibited by carbamyl and organophosphate inhibitors of acetylcholinesterase

7. Active Site of Acetylcholinesterase

8. Interaction of AChE and Acetylcholine

10. Acetylation of AChE and Release of Choline

11. Hydroxyl Group of Water Attacks the Carbonyl Group of Acetylated- AChE to Liberate AChE

12. Carbamyl Inhibitors of AChE