One of the reasons for preservation of biodiversity is to maintain sources for biomaterials “mining”. Stinging wasps are known for producing unique toxins that can have profound biological effects. Wasps use their venoms for defense or to immobilize prey. The venom must act on cells of the the target organism to be effective. Medical researchers are exploring wasp venom toxins for novel agents with potential for therapeutic uses.
The Brazilian wasp, Polybia paulista, produces a toxin called Polybia-MPI that specifically affects cells containing significant titers of the lipid, phosphatidylserine (PS), on the cell surface. This lipid can be common on tumor cells but is mostly absent from the surface of healthy cells. Polybia-MPI is an antibacterial peptide that selectively affects cells with external PS. Polybia-MPI acts on the membranes of these cells, making them “leaky” and ultimately killing the cell. Desirable features of Polybia-MPI are its selectivity and mode of action. Its target site and mode of action are unique and it is an effect agent against cancer cells that become resistant to agents with different targets.