Abstract
Snake venoms are complex protein mixtures with different biological activities that can act in both their preys and human victims. Many of these proteins play a role in prey capture and in the digestive process of these animals. It is known that some snakes are resistant to the toxicity of their own venom by mechanisms not yet fully elucidated. However, it was observed in the Laboratory of Herpetology of Instituto Butantan that some Bothrops moojeni individuals injured by the same snake species showed mortalities caused by envenoming effects. This study analyzed the biochemical composition of 13 venom and plasma samples from Bothrops moojeni specimens to assess differences in their protein composition. Application of sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) showed distinct venom protein profiles, but very homogeneous plasma profiles. Western Blotting (WB) was performed with plasma samples, which were submitted to incubation with the respective venom. Some individuals showed an immunorecognized band zone around 25 kDa, indicating interaction between the same individual plasma and venom proteins. Crossed-WB assay using non-self-plasma and venom showed that this variability is due to venom protein composition instead of plasma composition. These venoms presented higher caseinolytic, collagenolytic and coagulant activities than the venoms without these regions recognized by WB. Mass spectrometry analyses performed on two individuals revealed that these individuals present, in addition to higher protein concentrations, other exclusive proteins in their composition. When these same two samples were tested in vivo, the results also showed higher lethality in these venoms, but lower hemorrhagic activity than in the venoms without these regions recognized by WB. In conclusion, some Bothrops moojeni specimens differ in venom composition, which may have implications in envenomation. Moreover, the high individual venom variability found in this species demonstrates the importance to work with individual analyses in studies involving intraspecific venom variability and venom evolution.
Highlights
Snake venoms are probably one of the most complex of all known venoms, and are the most studied animal toxins since last century [1,2,3,4] to the present day [5,6,7,8,9]
Since it was in our best interest to identify the differences found previously, we decided for two individuals that represented, so to speak, the two different ‘groups’ that we identify with the Western Blotting (WB) test
Unveiling snake venom profiles and their biological activities contributes to the elucidation of their complex envenomation mechanism and assists with future research
Summary
Snake venoms are probably one of the most complex of all known venoms, and are the most studied animal toxins since last century [1,2,3,4] to the present day [5,6,7,8,9]. Several concepts were further established in the 19th century, including the one that the natural immunity is not species-specific [23] and can be found in other animals, such as several species of opossums, squirrels, mongooses, and hedgehogs [24,25,26,27]. This resistance is generally assigned to mutations in the gene encoding the target of the venom toxin, resulting in an insensitive target, and/or to the presence of neutralizing factors in the blood of resistant animals [28,29,30]
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call