Could a human be genetically engineered to produce a less fatal form of the Brazilian Wandering Spider’s Venom? I have been told that many things that insects can do do not function in humans for various reasons, so I would like to know if this could work.
In theory, yes this would be possible.
The neurotoxin in question (PhTx3) is a peptide, which means that almost any organsim can make it as long as it has the right DNA available. One difficulty with this problem is that the neurotoxins need the correct Cystein-Cystein bonds to fold correctly, which probably also prohibits people from making them from bacteria (Description of how the toxins where obtained to analyse them).
Now to the more important part: why would you want this?
It might be relatively easy to make any human cells produce this toxin. But then you have cells that poison (over time - doesn't matter if its weaker) all the nerves around them ... Since humans don't have ability to specifically deliver this poison anywhere its not really usefull ...