Why myotoxin-containing snake venoms possess powerful nucleotidases?

The venom of the snake Bothrops asper causes muscle necrosis, pain and inflammation. This venom contains
myotoxins which cause an increase in intracellular Ca2+ concentration and release of K+ and ATP
from myotubes. ATP is a key danger molecule that triggers a variety of reactions, including activation
of the innate immune response. Here, using ATP-luciferase bioluminescence imaging technique, we show
for the first time in vivo, that the purified myotoxins induce rapid release of ATP, whilst the complete
venom of B. asper does at a very small extent. This apparent contradiction is explained by the finding that
the venom contains powerful nucleotidases that in vivo convert ATP into ADP, AMP and Adenosine. These
findings indicate that high concentrations of adenosine are generated by the double action of the venom
and provide the experimental basis to the suggestion that in situ generated adenosine plays an important
role in envenomation via its hypotensive, paralyzing and anti-coagulant activities