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21 Cards in this Set
- Front
- Back
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Which amino acid residues located in the active site of acetylcholinesterase create the anionic site and how do they accomplish this?
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Trp 86 and Phe 338; the pi-stacking interactions create a negative environment (anionic site)
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What type of esterase is acetylcholinesterase?
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It's a serine esterase with a similar mechanism to chymotrypsin.
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How does atropine work in nerve gas treatment?
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It blocks muscarinic ACh receptors from the excess ACh present after AChE inhibition by nerve gases.
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How does pralidoxime chloride work in nerve gas treatment?
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The potent alpha group nucleophile mimics ACh and can reactivate nicotinic ACh receptors.
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What is the most common treatment for nerve gas poisoning?
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Duo-dote of atropine and pralidoxine chloride.
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What is an alpha group?
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Two heteroatoms right next to each other.
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What is theory behind using AChE inhibitors in Alzheimer's Disease?
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It will increase the concentration of ACh in the synapse to make up for a loss of ACh receptors.
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Which amino acid residue located in the active site of acetylcholinesterase acts as a nucleophile?
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Serine 203
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Do carbamates bind covalently to acetylcholinesterase?
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Yes.
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What type of acetylcholinesterase inhibitor can be used prior to nerve gas exposure to prevent binding?
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Carbamates.
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True or False: Carbamates cannot compete with irreversible acetylcholinesterase inhibitors.
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False.
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Why is the oxygen of a carbamate group always conjugated in acetylcholinesterase inhibitors?
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It makes the carbamate more electrophilic and thus a better substrate for the serine nucelophile of AchE.
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What type of acetylcholinesterase inhibitors bind reversibly to the anionic site?
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Amino groups, or ammonium groups.
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What functional groups on organophosphate drugs make them resistant to detoxification?
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The ester groups.
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What is the main role of acetylcholinesterase?
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To regulate the concentration of Ach in the synapse.
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What is an "aged enzyme"?
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This occurs when an organophosphate drug (such as a nerve agent) bound to acetylcholinesterase deteriorates and become completely irreversible.
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What does the DuoDote consist of?
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Atropine and pralidoxime chloride
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What are some examples of nerve agents?
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Sarin, VX, Soman and Tabun
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What is the functional group in pralidoxime chloride that undergoes the alpha effect?
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Oxime
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How is toxicity of insecticides achieved?
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The sulfur is oxidized to O, creating a toxic organophosphate in insects.
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Are carbamates considered reversible?
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Yes, they are slowly reversible.
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