Class Information

Question 1

Substrate Inhibition and it’s role in AChE regulation

Answer 1

Substrate inhibition is suprisingly common in enzymes (displayed by ~25%)

In AChE, this allows for sufficient time for acetylcholine to bind and transduce a signal before breaking it down.

This time-delay contributes to the on-off, switch-like behavior of neurons.

Question 2

Peripheral site on acetylcholinesterase

Answer 2

Prevents diffusion of choline, acetate, and water into/out of the active site, thus reducing the reaction velocity.

Primary mechanism for AChE’s substrate inhibition

Question 3

Myasthenia Gravis

Answer 3

Autoantibodies target and destroy acetylcholine receptors, leading to receptor death.

Diagnosed with edrophonium. Treated with neostigmine.

Atropine is sometimes given in conjunction, to prevent tearing and vomiting that can also be caused by neostigmine’s parasympathetic neuron activation.