Isolation and Characterization of A2-EPTX-Nsm1a, a Secretory Phospholipase A2 from Malaysian Spitting Cobra (Naja sumatrana) Venom.

Wayne C Hodgson,Nur Atiqah Haizum Abdullah,Iekhsan Othman,Muhamad Rusdi Ahmad Rusmili,Syafiq Asnawi Zainal Abidin,Mohd Farooq Shaikh

doi:10.3390/toxins13120859

Abstract

Phospholipase A2 (PLA2) toxins are one of the main toxin families found in snake venom. PLA2 toxins are associated with various detrimental effects, including neurotoxicity, myotoxicity, hemostatic disturbances, nephrotoxicity, edema, and inflammation. Although Naja sumatrana venom contains substantial quantities of PLA2 components, there is limited information on the function and activities of PLA2 toxins from the venom. In this study, a secretory PLA2 from the venom of Malaysian N. sumatrana, subsequently named A2-EPTX-Nsm1a, was isolated, purified, and characterized. A2-EPTX-Nsm1a was purified using a mass spectrometry-guided approach and multiple chromatography steps. Based on LC-MSMS, A2-EPTX-Nsm1a was found to show high sequence similarity with PLA2 from venoms of other Naja species. The PLA2 activity of A2-EPTX-Nsm1 was inhibited by 4-BPB and EDTA. A2-EPTX-Nsm1a was significantly less cytotoxic in a neuroblastoma cell line (SH-SY5Y) compared to crude venom and did not show a concentration-dependent cytotoxic activity. To our knowledge, this is the first study that characterizes and investigates the cytotoxicity of an Asp49 PLA2 isolated from Malaysian N. sumatrana venom in a human neuroblastoma cell line.

Highlights

Snake venom phospholipase A2 (PLA2) s are classified as secretory PLA2 s and are divided into Group I and Group II based on their molecular weight, calcium-dependency, and catalytic residues [6]
The results showed that A2-EPTX-NSm1a was less toxic to SH-SY5Y than its crude venom results showed that A2-EPTX-NSm1a was less toxic to SH-SY5Y than its crude venom
Sequence coverage with the neutral PLA2 muscarinic inhibitor (Q92084) (Table 1). These findings indicate that the molecular features and function of A2-EPTX-Nsm1a could be identical to the neutral phospholipase PLA2 muscarinic inhibitor

Summary

Introduction

A venomic study of Malaysian N. sumatrana venom showed that the venom consists mainly of three-finger toxins and phospholipase A2 (PLA2 ) components [5]. Information on the activity of PLA2 toxins from N. sumatrana venom is lacking despite these components being one of the main constituents of the venom. PLA2 s are ubiquitous components in many snake venoms. In some species, this amino acid residue is replaced by lysine, arginine, asparagine, serine, or, rarely, cysteine. Modification at this position alters the enzymatic activity of the PLA2 by modifying its Ca2+ binding dependency [7] and contributes to causing a different type of toxicity [8]

Methods

Results

Discussion

Conclusion