sentences:  Taipoxin and other PLA2 toxins have evolved from the digestive PLA2 enzymes.The venom still functions with the almost identical multi-disulphide-bridged protein PLA2 scaffold, which causes the hydrolytic mechanism of the enzyme.However it is thought that under strict evolution selection pressures of prey immobilisation and therefore extended feeding lead to the PLA2 enzyme losing its so called pancreatic loop and mutations for the toxin binding with pre-synaptic membranes of motor neuron end plates.