title: Venomics of the beaked sea snake, Hydrophis schistosus: A minimalist toxin arsenal and its cross-neutralization by heterologous antivenoms.
abstract: The venom proteome of Hydrophis schistosus (syn: Enhydrina schistosa) captured in Malaysian waters was investigated using reverse-phase HPLC, SDS-PAGE and high-resolution liquid chromatography-tandem mass spectrometry. The findings revealed a minimalist profile with only 18 venom proteins. These proteins belong to 5 toxin families: three-finger toxin (3FTx), phospholipase A2 (PLA2), cysteine-rich secretory protein (CRISP), snake venom metalloprotease (SVMP) and L-amino acid oxidase (LAAO). The 3FTxs (3 short neurotoxins and 4 long neurotoxins) constitute 70.5% of total venom protein, 55.8% being short neurotoxins and 14.7% long neurotoxins. The PLA2 family consists of four basic (21.4%) and three acidic (6.1%) isoforms. The minor proteins include one CRISP (1.3%), two SVMPs (0.5%) and one LAAO (0.2%). This is the first report of the presence of long neurotoxins, CRISP and LAAO in H. schistosus venom. The neurotoxins and the basic PLA2 are highly lethal in mice with an intravenous median lethal dose of <0.2 μg/g. Cross-neutralization by heterologous elapid antivenoms (Naja kaouthia monovalent antivenom and Neuro polyvalent antivenom) was moderate against the long neurotoxin and basic PLA2, but weak against the short neurotoxin, indicating that the latter is the limiting factor to be overcome for improving the antivenom cross-neutralization efficacy.
authors.affiliation: Department of Pharmacology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia; University of Malaya Centre for Proteomics Research, University of Malaya, 50603 Kuala Lumpur, Malaysia. Electronic address: tanchoohock@gmail.com.
authors.forename: Choo Hock
authors.initials: CH
authors.lastname: Tan
authors.affiliation: Department of Molecular Medicine, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: Kae Yi
authors.initials: KY
authors.lastname: Tan
authors.affiliation: Department of Molecular Medicine, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: Sin Ee
authors.initials: SE
authors.lastname: Lim
authors.affiliation: Department of Molecular Medicine, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia; University of Malaya Centre for Proteomics Research, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: Nget Hong
authors.initials: NH
authors.lastname: Tan
mesh_terms: D000818:Animals; D000997:Antivenins / Q000494:pharmacology; D004546:Elapid Venoms / Q000378:metabolism* / Q000633:toxicity; D017815:Elapidae / Q000378:metabolism*; D051379:Mice; D020543:Proteome / Q000378:metabolism*; D040901:Proteomics
chemical_list: D000997:Antivenins; D004546:Elapid Venoms; D020543:Proteome
keywords: Antivenom; Enhydrina schistosa; Hydrophis schistosus; Sea snake; Toxin neutralization; Venom proteome