Venom composition of Trimeresurus albolabris, T. insularis, T. puniceus and T. purpureomaculatus from Indonesia

Background: Several studies have been published on the characterization of Trimeresurus venoms. However, there is still limited information concerning the venom composition of Trimeresurus species distributed throughout Indonesia, which contributes to significant snakebite envenomation cases. The present study describes a comparative on the composition of T. albolabris, T. insularis, T. puniceus, and T. purpureomaculatus venoms originated from Indonesia. Methods: Protein content in the venom of four Trimeresurus species was determined using Bradford assay, and the venom proteome was elucidated using one-dimension SDS PAGE nano-ESI- LCMS/MS shotgun proteomics. Results: The venom of T. albolabris contained the highest protein content of 11.1 mg/mL, followed by T. puniceus, T. insularis and T. purpureomaculatus venom with 10.7 mg/mL, 8.9 mg/mL and 5.54 mg/mL protein, respectively. In total, our venomic analysis identified 65 proteins belonging to 16 protein families in T. purpureomaculatus; 64 proteins belonging to 18 protein families in T. albolabris; 58 different proteins belonging to 14 protein families in T. puniceus; and 48 different proteins belonging to 14 protein familiesin T. insularis. Four major proteins identified in all venoms belonged to snake venom metalloproteinase, C-type lectin, snake venom serine protease, and phospholipase A2. There were 11 common proteins in all venoms, and T. puniceus venom has the highest number of unique proteins compared to the other three venoms. Cluster analysis of the proteins and venoms showed that T. puniceus venom has the most distinct venom composition. Conclusions: Overall, the results highlighted venom compositional variation of four Trimeresurus spp. from Indonesia. The venoms appear to be highly similar, comprising at least four protein families that correlate with venom's toxin properties and function. This study adds more information on venom variability among Trimeresurus species within the close geographic origin and may contribute to the development of optimum heterologous antivenom.(AU)

Isolation, characterization and antigenic cross-reactivities of the major hemorrhagin from Cryptelytrops purpureomaculatus venom.

The major hemorrhagin from C. purpureomaculatus (mangrove pit viper) venom was purified to homogeneity and termed Maculatoxin. Maculatoxin has a molecular weight of 38 kDa as determined by SDS-PAGE. It is an acidic protein (pI= 4.2) and exhibited proteolytic and hemorrhagic activities (MHD10 = 0.84 μg in mice) but was not lethal to mice at a dose of 1 μg/g. The hemorrhagic activity of Maculatoxin was completely inactivated by EDTA and partially inhibited by ATP and citrate. The N-terminal sequence of Maculatoxin (TPEQQRFPPTYIDLGIFVDHGMYAT) shares a significant degree of homology with the metalloprotease domain of other venom hemorrhagins. Indirect ELISA showed anti-Maculatoxin cross reacted with protein components of many snake venoms. In the double-sandwich ELISA, however, anti-Maculatoxin cross-reacted only with venoms of certain species of the Trimeresurus (Asia lance-head viper) complex, and the results support the recent proposed taxonomy changes concerning the Trimeresurus complex