Venom proteome of Malaysian Bungarus candidus and Bungarus fasciatus

• Main Authors: Othman, Iekhsan, Ahmad Rusmili, Muhamad Rusdi, Ting, Tee Yee, Hodgson, Wayne C.
• Format: Conference or Workshop Item
• Language: English; English
• Published: 2014
• Subjects: QD Chemistry; RS Pharmacy and materia medica
• Online Access: http://irep.iium.edu.my/37200/1/ASMS_PosterTemplate_7.pdf; http://irep.iium.edu.my/37200/4/rusdi.pdf; http://irep.iium.edu.my/37200/; http://www.asms.org

Novel Aspect A first report of natriuretic peptide in Bungarus venom exhibiting hyponatremic effects together with serine protease and different neurotoxins compositions. Introduction Snake envenoming is now considered to be a neglected tropical disease by the World Health Organisation. Mortality and morbidity from snakebite is particularly prevalent in under developed and developing countries. Bungarus candidus and B. fasciatus are two medically important venomous snakes in Malaysia. Even though krait bite is relatively rare in Malaysia, the emergence of newly observed symptoms such as hyponatremia, myotoxicity and cardiovascular effects warrant closer examination of the composition of their venoms. In addition, it has been suggested that monovalent Bungarus fasciatus antivenom is not a suitable treatment of Bungarus candidus envenoming. In this study, we would like to describe proteome and compare composition of Malaysian B. candidus and B. fasciatus venoms by using a "bottom-up" proteomics approach. Methods Pooled Malaysian B. candidus and B. fasciatus venoms were obtained from a private collector. The venoms were fractionated by reverse-phase HLPC and fractions collected and freeze-dried. Fractions were also run on SDS-PAGE gels stained with Coomassie blue and destained with 5% acetic acid. The gel bands were later cut and digested by an in-gel digestion method. In parallel, 10 µg of each fraction was digested by an in-solution digestion method. Digested samples were later analysed by LCMS/MS and protein identification was conducted using PEAKS Studio 7. The percentage of identified proteins were tabulated using GraphPad Prism. Preliminary Data We found that both venoms contain three-finger toxins (3FTx), phospholipase A2 (PLA2), L-amino acid oxidase (LAAO), acetylcholinesterase, snake venom metalloproteinase (SVMP), and Kunitz-type protease inhibitor families which supports previous work on venom gland transcriptomes and crude venom. Most of the detected venom proteins were homologous to proteins that have been described either in transcript and proteome levels from B. multicinctus, B. fasciatus and B. candidus. The three-finger toxin family was the most abundant toxin family in Malaysian B. candidus venom whereas PLA2 was the most abundant toxin family in Malaysian B. fasciatus venom. Closer examination of the proteomes showed that there were differences in the composition of three-finger toxins in both venoms. Unlike B. candidus venom, B. fasciatus venom was devoid of long-chain neurotoxins and composed only of short-chain neurotoxins and non-conventional neurotoxins. No kappa-neurotoxins were detected in B. fasciatus venom. PLA2 components, that have previously been detected in Bungarus venoms, were detected as were PLA2 components which are homologous to PLA toxins found in cobras and Australian elapid venoms. β-bungarotoxin was previously thought not to be present in B. fasciatus venom but we have detected a presence of a subunit in the venom. In addition to previously described venom proteins in both Bungarus venoms, we have also detected the presence of previously undescribed toxin families in both venoms. We have detected presence of serine proteases in both venoms which were previously only described in B. multicinctus venom gland trancripts and isolated from Cerestes cerestes venom. We also detected the presence of a natriuretic peptide in B. candidus venom which is homologous to a natriuretic peptide from Ophiophagus hannah venom.