Proteomics analysis to compare the venom composition between Naja naja and Naja kaouthia from the same geographical location of eastern India: Correlation with pathophysiology of envenomation and immunological cross-reactivity towards commercial polyantivenom

ABSTRACT

Background : Cobra bite is frequently reported across the Indian subcontinent and is associated with a high rate of death and morbidity. In eastern India (EI) Naja naja and Naja kaouthia are reported to be the two most abundant species of cobra.

Research design and methods : The venom proteome composition of N. naja (NnV) and N. kaouthia (NkV) from Burdwan districts of EI were compared by separation of venom proteins by 1D-SDS-PAGE followed by LC-MS/MS analysis of protein bands. The potency of commercial polyantivenom (PAV) was assessed by neutralization, ELISA, immuno-blot and venom-PAV immunoaffinity chromatography studies.

Results : Proteomic analysis identified 52 and 55 proteins for NnV and NkV, respectively, when searched against the Elapidae database. A small quantitative difference in venom composition between these two species of cobra was observed. PAVs exhibited poor cross-reactivity against low molecular mass toxins (<20 kDa) of both cobra venoms, which was substantiated by a meager neutralization of their phospholipase A₂ activity. Phospholipase A₂ and 3FTx, the two major classes of nonenzymatic and enzymatic proteins, respectively, were partially recognized by PAVs.

Conclusions : Efforts must be made to improve immunization protocols and supplement existing antivenoms with antibodies raised against the major toxins of these venoms.

KEYWORDS:

• Antivenomics
• cobra venom
• snakebite
• snake venom
• venom-antivenom cross-reactivity

Acknowledgments

The authors thank C-CAMP, NCBS, Bangalore, and KIIT-TBI, Bhubaneswar, India for LC-MS/MS analysis and Dr. Glen D. Wheeler, Owl editing, Canada for editing the manuscript. AC, AP, and BK received fellowships from DBT National Bioscience Award for Career Development, DST-SERB, AISTDF, and DBT U-Excel project grants, respectively. The study received financial assistance from DBT, New Delhi sponsored Unit of Excellence in Biotechnology in NER of India project (BT/412/NE/U-Excel/2013), and partial support from DST-SERB, AISTDF New Delhi sponsored project grant (IMRC/AISTDF/R&D/P-3/2017) to AKM.

Author contributions

A.K. Mukherjee conceived the idea, designed the study, and edited the final manuscript; A. Chanda, A. Patra and B. Kalita performed the experiments; A.K. Mukherjee, A. Chanda, A. Patra, and B. Kalita analyzed the data and wrote the manuscript.

Declaration of interest

The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Supplementary Material

Supplementary data for this article can be accessed here

Additional information

Funding

This paper received financial assistance from Department of Biotechnology, Ministry of Science and Technology (grant number: BT/412/NE/U-Excel/2013), and partial support from Department of Science and Technology, Science and Engineering Research Board (grant number: IMRC/AISTDF/R&D/P-3/2017) to A.K. Mukherjee.