How does a animal eukaryotic cell destroy toxins such as Botox.

Question

We are doing an exam essay on a journey through the cell, where you have been shrunk and operate and manoeuvre through the cell by a ship of some sort. The question asks 'You have been attacked by a lysosome and some of the digestive enzymes damage your ship which results in the leakage of Botox from your ship. Fortunately, a cell destroys it. Explain how this occurs'. Would like to know ASAP as our exam essay is tomorrow.

Thanks, Samad

Answer 1

Hello, Samad,

 

Although this answer may be a bit late to help with your exam, perhaps it might help you understand the mechanism of cell based metabolism of botox. First, most cells can't metabolize botox, since it binds only to cholinergic nerve endings in neurons. Only these cells have the ability to selectively accumulate and breakdown the molecule. When the toxin moves from the cell membrane to the cell interior, it undergoes programmed death. This is coincident with release of the catalytically active light chain that paralyzes transmission. Intraneuronal metabolism of light chain is via the ubiquitination-proteasome pathway. It is also eliminated by enzymatic degradation and rebuilding of the neuronal plates to which botox attaches.  Systemic metabolism and elimination is assumed to be via the liver.  Very likely the correct answer your teacher was looking for was for metabolism by macrophage or similar phagocytic cells, but this is not the case in reality as far as I can determine from the literature. 

 

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