Question

Toxins, such as those from the bacterium Clostridium, cause diseases such as botulism and tetanus by destroying proteins that anchor vesicles to the presynaptic membrane. How might this affect activity in the neuromuscular junction

Answer 1

Action of toxins from the bacterium Clostridium at the neuromuscular junctions

Explanation:

Toxins produced by bacterium like Clostridium botulinum (BoNT, botulinum) and C. tetanus (TeNT) lethal neurotoxins which affect the nervous pathways.

These neurotoxins are proteolytic enzymes which cleave or destroy the SNAP Receptor (SNARE) proteins which anchor the vesicles to the synaptic membrane. The SNARE proteins help in vesicular fusion and are targeted by the neurotoxins which makes them inactive.

Due to this inactivity of SNARE proteins, fusion of synaptic vesicles to synaptic membrane is affected and prevents the flow of neurotransmitters in the synaptic cleft, which in turn stops propagation of action potentials in the muscle cells. This toxic activity may even lead to paralysis of muscles.