Equatorial Spitting Cobra (Naja sumatrana) from Malaysia (Negeri Sembilan and Penang), Southern Thailand, and Sumatra: Comparative Venom Proteomics, Immunoreactivity and Cross-Neutralization by Antivenom

Abstract

The Equatorial Spitting Cobra (Naja sumatrana) is a medically important venomous snake species in Southeast Asia. Its wide geographical distribution implies potential intra-specific venom variation, while there is no species-specific antivenom available to treat its envenoming. Applying a protein-decomplexing proteomic approach, the study showed that three-finger toxins (3FTX), followed by phospholipases A2 (PLA2), were the major proteins well-conserved across N. sumatrana venoms of different locales. Variations were noted in the subtypes and relative abundances of venom proteins. Of note, alpha-neurotoxins (belonging to 3FTX) are the least in the Penang specimen (Ns-PG, 5.41% of total venom proteins), compared with geographical specimens from Negeri Sembilan (Ns-NS, 14.84%), southern Thailand (Ns-TH, 16.05%) and Sumatra (Ns-SU, 10.81%). The alpha-neurotoxin abundance, in general, correlates with the venom’s lethal potency. The Thai Naja kaouthia Monovalent Antivenom (NkMAV) was found to be immunoreactive toward the N. sumatrana venoms and is capable of cross-neutralizing N. sumatrana venom lethality to varying degrees (potency = 0.49–0.92 mg/mL, interpreted as the amount of venom completely neutralized per milliliter of antivenom). The potency was lowest against NS-SU venom, implying variable antigenicity of its lethal alpha-neurotoxins. Together, the findings suggest the para-specific and geographical utility of NkMAV as treatment for N. sumatrana envenoming in Southeast Asia.

In Vitro neurotoxicity and myotoxicity of Malaysian Naja sumatrana and Naja kaouthia venoms: Neutralization by monovalent and Neuro Polyvalent Antivenoms from Thailand

“…kaouthia and N . sumatrana venoms were reported to have significant impact of the effectiveness of antivenoms [ 36 – 38 ].…”

“…This could be due to the wider distribution of N. kaouthia and medical importance of this biting species in the localities where it is found. Geographic variations in the composition of N. kaouthia and N.sumatrana venoms were reported to have significant impact of the effectiveness of antivenoms [36][37][38].…”

De Novo Venom Gland Transcriptome Assembly and Characterization for Calloselasma rhodostoma (Kuhl, 1824), the Malayan Pit Viper from Malaysia: Unravelling Toxin Gene Diversity in a Medically Important Basal Crotaline

“…The apparently higher abundance of PLA 2 transcripts in the venom gland transcriptome is puzzling, suggesting complex regulation of the mRNA half-life and protein translation that cannot be simplified by a single snapshot of the transcriptomic profile. In fact, the disproportionate expression between PLA 2 transcripts and proteins is not uncommon, as reported in a number of venom gland transcriptomics studies for Naja kaouthia [ 27 , 64 ], Naja sumatrana [ 29 , 65 ], Ophiophagus hannah [ 28 ], Hydrophis curtus [ 31 , 66 ], and Calliophis bivirgata [ 30 , 67 ], when venom glands were harvested 3–4 days post-venom milking.…”

Anticancer Activity of Venom Protein Hydrolysis Fraction of Equatorial Spitting Cobra (<i>Naja sumatrana</i>)

“…N. sumatrana venom from four different regions, namely Penang, Negeri Sembilan, Southern Thailand, and Sumatra, showed that the three-finger toxins (3FTxs) components followed by phospholipase A 2 (PLA 2 ) were the main proteins present in all N. sumatrana venoms. Seven protein families were consistently identified from the four regions, including three-finger toxins (3FTX), phospholipase A 2 (PLA 2 ), phosphodiesterase (PDE), L-amino acid oxidase (LAAO), venom nerve growth factor (vNGF), snake venom metalloproteinase (SVMP), and cobra venom factor (CVF) [22]. Components of snake venom, such as PLA 2 , are enzymatic proteins that have various pharmacological activities and are usually present in snake venom [23].…”