From birth to adulthood: An analysis of the Brazilian lancehead (Bothrops moojeni) venom at different life stages.

The Brazilian lancehead (Bothrops moojeni) has a wide distribution in Brazil and represents a serious public health hazard. Previous works reported that the symptoms of snakebites caused by B. moojeni juveniles' bites were mainly related to coagulation, while those caused by adults' bites had a more prominent local damage. In this work, we analyzed the venoms of B. moojeni at different life stages to better understand the ontogeny shift in this species. Snakes were grouped by age and sex, and venom pools were formed accordingly. Compositional analyses by one-dimensional electrophoresis (1-DE), chromatography, and mass spectrometry revealed that ontogenetic changes might be mostly related to phospholipase A2 (PLA2) and metalloproteases. Regarding the venoms functional aspect, proteolytic, L-amino acid oxidase, PLA2, and coagulant in vitro activities were assayed, but only the first and the last ones showed age-related changes, with the venom of snakes up to 1 year-old displaying lower proteolytic and higher coagulant activities, while those from 2 years-old onward presented the opposite relation. The venoms of 3 years-old snakes were exceptions to the compositional and functional pattern of adults as both venoms presented profiles similar to neonates. Sex-related differences were observed in specific groups and were not age-related. In vivo experiments (median lethal dose and hemorrhagic activity) were statistically similar between neonates and adults, however we verified that the adult venom killed mice faster comparing to the neonates. All venoms were mostly recognized by the antibothropic serum and displayed similar profiles to 1-DE in western blotting. In conclusion, the Brazilian lancehead venom showed ontogenetic shift in its composition and activities. Furthermore, this change occurred in snakes from 1 to 2 years-old, and interestingly the venom pools from 3 years-old snakes had particular characteristics, which highlights the importance of comprehensive studies to better understand venom variability.

Identification of proteins similar to Bothrops jararaca coagulation inhibitor (BjI) in the plasmas of Bothrops alternatus, Bothrops jararacussu and Crotalus durissus terrificus snakes.

Bothrops jararaca coagulation inhibitor (BjI), a protein isolated from B. jararaca plasma, specifically inhibits the coagulant activity of thrombin. Our group previously identified proteins similar to BjI in the plasma of other snakes [Tanaka-Azevedo, A.M., Tanaka, A.S., Sano-Martins I.S., 2003. A new blood coagulation inhibitor from the snake Bothrops jararaca plasma: isolation and characterization. Biochem Biophys Res Commun 308, 706-712.]. In the present study, we analyzed the presence of BjI-like proteins in the plasmas of three different species of viperid snakes, Bothrops alternatus, Bothrops jararacussu and Crotalus durissus terrificus. These proteins exhibited 109 and/or 138 kDa and were immunologically related to BjI. They also inhibited the coagulant activity of thrombin, evaluated by the thrombin time test. These findings demonstrate the presence of proteins similar to BjI in these three species, although such inhibitor could not be observed in all samples of the specimens tested. Moreover, the presence of these proteins in the plasma is related to prolongation of thrombin time, implying a relationship between these proteins and their inhibitory coagulant activity upon thrombin. Our results suggest that BjI-like proteins are widely distributed among Crotalinae snakes found in Brazil.