A New Group II Phospholipase A2 from Walterinnesia aegyptia Venom with Antimicrobial, Antifungal, and Cytotoxic Potential

Abstract

Many venomous species, especially snakes, contain a variety of secreted phospholipases A2 that contribute to venom toxicity and prey digestion. We characterized a novel highly toxic phospholipase A2 of group II, WaPLA2-II, from the snake venom of Saudi Walterinnesia aegyptia (W. aegyptia). The enzyme was purified using a reverse phase C18 column. It is a monomeric protein with a molecular weight of approximately 14 kDa and an NH2-terminal amino acid sequence exhibiting similarity to the PLA2 group II enzymes. WaPLA2-II, which contains 2.5% (w/w) glycosylation, reached a maximal specific activity of 1250 U/mg at pH 9.5 and 55 °C in the presence of Ca2+ and bile salts. WaPLA2-II was also highly stable over a large pH and temperature range. A strong correlation between antimicrobial and indirect hemolytic activities of WaPLA2 was observed. Additionally, WaPLA2-II was found to be significantly cytotoxic only on cancerous cells. However, chemical modification with para-Bromophenacyl bromide (p-BPB) inhibited WaPLA2-II enzymatic activity without affecting its antitumor effect, suggesting the presence of a separate ‘pharmacological site’ in snake venom phospholipase A2 via its receptor binding affinity. This enzyme is a candidate for applications including the treatment of phospholipid-rich industrial effluents and for the food production industry. Furthermore, it may represent a new therapeutic lead molecule for treating cancer and microbial infections.

Functional Characterization and Anti-Tumor Effect of a Novel Group II Secreted Phospholipase A2 from Snake Venom of Saudi Cerastes cerates gasperetti

“…In this regard, interestingly, Cc-PLA 2 -II displayed a high catalytic activity at 50 °C ( Figure 2 B). This activity at high temperatures has also been observed with the same snake-venom sPLA 2 , such as CC-PLA 2 from Tunisian Cerastes cerastes , which is fully active at 60 °C [ 9 ], and Wa-PLA 2 -II [ 7 ] and PLA 2 from Austrelaps superba [ 39 ], with maximum activity at 55 °C and 50 °C, respectively. According to Iyer et al, thermophilic and mesophilic proteins have similar three-dimensional structures but are different in their active site residues.…”

“…Based on their primary structural homology and disulfide bonding pattern, snake venom sPLA 2 is classified into two groups: I and II [ 6 ]. Group II is found in viperidea venom, while group I characterizes Elapidae and Hydrophidae snake venom [ 7 ]. These groups can be further divided into subgroups—active Asp49-PLA 2 and Lysine 49-PLA 2 —which are catalytically inactive due to their inability to bind calcium [ 8 ].…”

“…These enzymes, which associated or not with toxins, are described to be responsible for tumor regression through cytotoxicity against human cancer cells [ 8 ]. Indeed, sPLA 2 isolated from Bothrops asper , Bothrops moojeni , Naja naja , and Walterinnesia aegyptia snake venom showed cytotoxicity against mouse adrenal tumor cells, Ehrlich ascites tumor, human breast adenocarcinoma, leukemia, and colorectal carcinoma [ 7 , 8 ]. sPLA 2 from Russell’s viper venom altered melanoma tumor cell adhesion in vitro, in turn affecting tumor mass growth in vivo [ 11 ].…”

Egyptian cobra (Naja haje haje) venom phospholipase A2: a promising antiviral agent with potent virucidal activity against simian rotavirus and bovine coronavirus

“…The molecular mass of the purified N. haje PLA2 was in agreement with the range generally reported for snake venom PLA2 (14–18 kDa) (Six and Dennis 2000 ). Furthermore, the molecular masses of the Egyptian Naja nigricollis and Saudi Walterinnesia aegyptia were approximately 14 kDa (Wahby et al 2013 ; Abid et al 2020 ). A hemolytic band of low molecular weight was resolved when PLA2 was loaded in 15% SDS-PAGE under non-reducing conditions and then placed on RBCs–egg yolk–agarose gel activity (Fig.…”

Effective Soybean Oil Degumming by Immobilized Phospholipases A2 from Walterinnesia aegyptia Venom

“…W. aegyptia group-I (WaPLA 2 -I) and WaPLA 2 -II were purified as previously described by Bacha et al and Abid et al, respectively.…”