Isolation and Characterization of A2-EPTX-Nsm1a, a Secretory Phospholipase A<sub>2</sub> from Malaysian Spitting Cobra (<i>Naja sumatrana</i>) Venom

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

Format: Article
Diterbitkan: MDPI AG 2021-12-01

Deskripsi

Phospholipase A<sub>2</sub> (PLA<sub>2</sub>) toxins are one of the main toxin families found in snake venom. PLA<sub>2</sub> toxins are associated with various detrimental effects, including neurotoxicity, myotoxicity, hemostatic disturbances, nephrotoxicity, edema, and inflammation. Although <i>Naja sumatrana</i> venom contains substantial quantities of PLA<sub>2</sub> components<sub>,</sub> there is limited information on the function and activities of PLA<sub>2</sub> toxins from the venom. In this study, a secretory PLA<sub>2</sub> from the venom of Malaysian <i>N. sumatrana</i>, 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 PLA<sub>2</sub> from venoms of other <i>Naja</i> species. The PLA<sub>2</sub> 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 PLA<sub>2</sub> isolated from Malaysian <i>N. sumatrana</i> venom in a human neuroblastoma cell line.