Combined venom gland cDNA sequencing and venomics of the New Guinea small-eyed snake, Micropechis ikaheka URL Artículo académico uri icon

Abstracto

  • The venom arsenal of the New Guinea small-eyed snake, Micropechis ikaheka, was investigated by a joint cDNA sequencing and venomics approach. Twenty-seven full-length DNA sequences encoding novel venom proteins were recovered in this study. Using this cDNA dataset we achieved locus-specific resolution for 19 out of the approximately 50 reverse-phase- and SDS-PAGE-separated venom proteins. The venom proteome of M. ikaheka is dominated by at least 29 D49-phospholipase A2 (PLA2) and 14 short and long neurotoxins of the three-finger toxin (3FTx) family. These protein classes represent, respectively, 80% and 9.2% of the total venom proteins. Two PIII-metalloproteinase (SVMP) molecules (7.6%), three CRISP isoforms (1.8%), and a single Kunitz-type inhibitor, vespryn, 5′-nucleotidase, serine proteinase and LAO molecules, none of which represents more than 0.7% of the total venom proteome, complete the protein arsenal of M. ikaheka. In concordance with clinical observations, this venom composition points to a central role for post-synaptically-acting neurotoxic toxins in the envenomation strategy developed by this species. PLA2 molecules represent the main myotoxic components of M. ikaheka venom. In addition, the estimated LD50 for mice of the reverse-phase-isolated 3FTx (0.22 mg/kg) and PLA2 (1.62 mg/kg) enriched fractions, strongly suggests that these two toxin classes contribute synergistically to venom lethality, with the 3FTxs playing a dominant role. The high structural and functional conservation exhibited by M. ikaheka and Australian elapid venoms may underlay the positive clinical outcomes of envenoming resulting from bites by M. ikaheka that have been documented through the use of bioCSL polyvalent antivenom.

fecha de publicación

  • 2014