Many species of snakes are considered to be of the highest medical importance by WHO. Better understanding the composition and function of poisons is a priority.
Venom characterization of 26 sub-Saharan African snakes demonstrates the benefits of integrated high-throughput analysis. Approximately 500,000 people in sub-Saharan Africa are affected by snakebites each year, resulting in an estimated 7,000 to 20,000 deaths . Many snake species native to the region, such as the feared black mamba ( Dendroaspis polylepis Günther, 1864), are classified as species of greatest medical importance by the World Health Organization. The Center for Antibody Technologies, headed by Professor Andreas Laustsen-Kiel (Technical University of Denmark), used high-throughput methods(all those scientific analyzes capable of carrying out tests on a very large number of data in a short time thanks to automated machinery and instruments) to systematically analyze and compare the protein composition and the functions of the venoms of the 26 most important snakes from the point of medical view of sub-Saharan Africa. The article was published in Gigascience journal.
The snakes analyzed in the new study belong to two families, the E lapidae – which include, among others, the black and green mambas ( Dendroaspis angusticeps) and the spitting cobra ( Naja nigricollis) , and the South African spitting cobra Hemachatus haemachatus (its venom can cause serious damage to the cornea.Many cases of poisoning have led to permanent blindness) – and viperids such as the puff adder ( Bitis arietans) and the Gaboon viper ( Bitis gabonica) .
The composition and function of snake venoms is complex and varies widely from species to species. The authors describe a general pattern : elapid venoms contain large amounts of a class of proteins called “three-finger toxins ,” which work by blocking neuronal transmission or killing cells, as well as phospholipase A2 (PLA2), a class of enzymes present in many animal venoms. Pit viper venoms , on the other hand, are dominated by a different protein mix , which includes PLA2 , but also substantial amounts of other enzymes such as metalloproteinases and serine-proteinases of snake venom.
The venom composition of most of these snakes has been previously described, but the venoms of two species – Anchieta’s cobra (Naja anchietae) and the white-bellied pit viper (Echis leucogaster) – have been characterized for the first time in GigaScience’s new study.
The main advance of the work, however, is the parallel processing of samples from 26 snakes in the same high-throughput pathway, combined with a series of experimental approaches to functionally characterize many venoms in parallel, in a standardized setting. In contrast, previous studies of the venom composition of sub-Saharan African snakes have typically been conducted in separate studies with only one or a few species each, and often with little or no data on functional aspects. Previous studies have also used variable protocols, making it difficult to reconcile and compare data from different sources.
The novel integrated approach demonstrated in the article provides a solid foundation for further study of snake biology and the development of new antivenoms .
- High-throughput proteomics and in vitro functional characterization of the 26 medically most important elapids and vipers from sub-Saharan Africa (academic.oup.com)