This study focuses on comprehensive characterization of the
venom proteome of the beaked sea snake (Hydrophis schistosus) from Songkhla Lake, Thailand. H. schistosus can be considered as the deadliest sea snake commonly found in the Pacific and Indian oceans. Their envenomation causes muscular
paralysis and
rhabdomyolysis. To develop effective treatment for this
snakebite, it is necessary to understand the detailed
venom composition. In this study, multiple mass spectrometry-based approaches were employed. Bottom-up proteomics revealed that tryptic digestion in-
solution provided a higher number of toxin
proteins identified and a larger sequence coverage, compared to in-gel digestion. In addition, a
venom gland transcriptome-derived database was constructed and used as a reference, which 43 known and novel toxin
proteins were identified using this database and the UniProtKB.
Three-finger toxin and
phospholipase A2 were shown to be top two most abundant
protein families. Minor compositions included other toxin families and a number of non-toxin
proteins. Moreover, a hybrid de novo sequencing was performed to enhance identification of the small
proteins/
peptides. Using non-digested samples, there were 46 predicted toxin
peptides. The finding from this study could lead to a better understanding in pathological effects of the
snakebite and the future development of effective
antivenoms. SIGNIFICANCE: This study provides a better understanding of the
venom proteome composition of the beaked sea snake (H. schistosus) found in the Gulf of Thailand, using a combination of different sample preparation techniques, Serpentes protein database searching, transcriptome-derived protein database searching, and a hybrid de novo
peptide sequencing strategy. It revealed 13 toxin
protein families and novel
proteins in the beaked sea snake
venom including new species of
phospholipase A2s (PLA2s) and
three-finger toxins (
3FTxs). It could serve as a basis for the development of
snakebite treatments and for the discovery of novel
pharmaceutical drugs from the toxin
peptides.