Question

The Japanese giant hornet injects venom into its victims that contains, among other things, a neurotoxin called mandaratoxin. The neurotoxin acts by blocking voltage-gated Na+ channels. a) How would mandaratoxin kill an animal that was stung by the hornet? b) Suppose you discover a new species of hornet and you want to know if its venom contains a similar neurotoxin. Describe an experiment you could do to find out.

Answer 1

a)

Mandaratoxin, a 19 kDa protein irreversibly reduces Na+ current.

b)

A typical effect of toxin on the neuromuscular junction can be tested with lobster walking leg experiment.

If the neurotoxin applied to the lobster neuromuscular junction causes the amplitude of the excitatory postsynaptic potentials (EPSP’s) to decline within a few minutes and the larger doses of neurotoxin tend to shorten the time for blocking represent that it blocks the voltage-gated Na+ channels similar to Mandaratoxin.