TMTFA

TMTFA is an extremely potent acetylcholinesterase inhibitor. As a transition state analog of acetylcholinesterase, TMTFA is able to inhibit the acetylcholinesterase at extremely low concentrations (within the femtomolar range), making it one of the most potent acetylcholinesterase inhibitors known.
Mechanism of action.
TMTFA has a reactive ketone group that can covalently bind to the serine residue in the active site of acetylcholinesterase. This is due to the electron-withdrawing trifluoromethyl group on the carbonyl group.