A novel bactericidal homodimeric PLA2 group-I from Walterinnesia aegyptia venom

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

Enzymatic degumming utilizing phospholipase enzymes could be used in ecologically friendly procedures with enhanced oil recovery yields. In this study, two phospholipases A2 of group I and II, WaPLA2-I and WaPLA2-II, from the snake venom of Saudi Walterinnesia aegyptia were evaluated for soybean oil degumming after being immobilized on three different support materials (calcium alginate (CA), CA-gelatin (CAG), and CA-chitosan (CAC), and cross-linked with glutaraldehyde). Higher yields of CAC-immobilized PLA2-I (85 ± 3%) and PLA2-II (87 ± 3.6%) compared to CAG (77.3 ± 2.1 and 79 ± 2.6%, respectively) and CA beads (55.7 ± 2.5% and 57.3 ± 3.1%, respectively) were observed. In addition, the optimal temperature of immobilized WaPLA2-I and WaPLA2-II increased from 45 to 55 °C and from 55 to 65 °C, respectively. Their stability at high temperatures was also significantly enhanced covering a larger range (70-80 °C). Likewise, the pH/activity profile of WaPLA2 was greatly expanded upon immobilization with the pH-optima being shifted by 0.5 to 1 pH unit to the basic side. Similarly, the stability of WaPLA2s in the presence of organic solvents was also significantly improved, while the affinity for calcium and bile salt was the same for both free and immobilized enzymes. Interestingly, the remaining activity of immobilized WaPLA2 onto different supports was more than 50 or 60% after eight recycles or 120 days of storage at 4 °C, respectively. CAC-WaPLA2-II was the best immobilized enzyme complex for the oil degumming process by reducing its final residual phosphorus content from 168 mg/kg to less than 10 mg/kg in only 4 h. Overall, CAC-WaPLA2-II showed the most attractive profiles of temperature, pH, and reaction duration as well as significant storage stability and reusability.

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

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.

Venom peptides in association with standard drugs: a novel strategy for combating antibiotic resistance - an overview

Development of antibiotic resistance that leads to resurgence of bacterial infections poses a threat to disease-free existence for humankind and is a challenge for the welfare of the society at large. Despite research efforts directed towards treatment of pathogens, antibiotics within new improved classes have not emerged for years, a fact largely attributable to the pharmacological necessities compelling drug development. Recent reversion to the use of natural products alone or in combination with standard drugs has opened up new vistas for alternative therapeutics. The success of this strategy is evident in the sudden interest in plant extracts as additives/synergists for treatment of maladies caused by drug-resistant bacterial strains. Animal venoms have long fascinated scientists as sources of pharmacologically active components that can be exploited for the treatment of specific ailments and should be promoted further to clinical trials. In the present review, we outline the scope and possible methods for the applications of animal venoms in combination with commercial antibiotics to offer a better treatment approach against antibiotic-resistant infections.

Antimicrobial Activity of Protein Fraction from Naja ashei Venom Against Staphylococcus epidermidis

One of the key problems of modern infectious disease medicine is the growing number of drug-resistant and multi-drug-resistant bacterial strains. For this reason, many studies are devoted to the search for highly active antimicrobial substances that could be used in therapy against bacterial infections. As it turns out, snake venoms are a rich source of proteins that exert a strong antibacterial effect, and therefore they have become an interesting research material. We analyzed Naja ashei venom for such antibacterial properties, and we found that a specific composition of proteins can act to eliminate individual bacterial cells, as well as the entire biofilm of Staphylococcus epidermidis. In general, we used ion exchange chromatography (IEX) to obtain 10 protein fractions with different levels of complexity, which were then tested against certified and clinical strains of S. epidermidis. One of the fractions (F2) showed exceptional antimicrobial effects both alone and in combination with antibiotics. The protein composition of the obtained fractions was determined using mass spectrometry techniques, indicating a high proportion of phospholipases A₂, three-finger toxins, and L-amino acids oxidases in F2 fraction, which are most likely responsible for the unique properties of this fraction. Moreover, we were able to identify a new group of low abundant proteins containing the Ig-like domain that have not been previously described in snake venoms.

Antibacterial properties of snake venom components

An increasing problem in the field of health protection is the emergence of drug-resistant and multi-drug-resistant bacterial strains. They cause a number of infections, including hospital infections, which currently available antibiotics are unable to fight. Therefore, many studies are devoted to the search for new therapeutic agents with bactericidal and bacteriostatic properties. One of the latest concepts is to search for this type of substances among toxins produced by venomous animals. In this approach, however, special attention is paid to snake venom because it contains molecules with antibacterial properties. Thorough investigations have shown that the phospholipases A2 (PLA2) and l-amino acids oxidases (LAAO), as well as fragments of these enzymes, are mainly responsible for the bactericidal properties of snake venoms. Some preliminary research studies also suggest that fragments of three-finger toxins (3FTx) are bactericidal. It has also been proven that some snakes produce antibacterial peptides (AMP) homologous to human defensins and cathelicidins. The presence of these proteins and peptides means that snake venoms continue to be an interesting material for researchers and can be perceived as a promising source of antibacterial agents.

Distinctive Distribution of Secretory Phospholipases A₂ in the Venoms of Afro-Asian Cobras (Subgenus: Naja, Afronaja, Boulengerina and Uraeus)

The protein abundances of phospholipases A₂ in cobra venom proteomes appear to vary among cobra species. To determine the unique distribution of snake venom phospholipases A₂ (svPLA₂) in the cobras, the svPLA₂ activities for 15 cobra species were examined with an acidimetric and a colorimetric assay, using egg yolk suspension and 4-nitro-3-octanoyloxy benzoic acid (NOBA) as the substrate. The colorimetric assay showed significant correlation between svPLA₂ enzymatic activities with the svPLA₂ protein abundances in venoms. High svPLA₂ activities were observed in the venoms of Asiatic spitting cobras (Naja sputatrix, Naja sumatrana) and moderate activities in Asiatic non-spitters (Naja naja, Naja atra, Naja kaouthia), African spitters (subgenus Afronaja), and forest cobra (subgenus Boulengerina). African non-spitting cobras of subgenus Uraeus (Naja haje, Naja annulifera, Naja nivea, Naja senegalensis) showed exceptionally low svPLA₂ enzymatic activities. The negligible PLA₂ activity in Uraeus cobra venoms implies that PLA₂ may not be ubiquitous in all snake venoms. The svPLA₂ in cobra envenoming varies depending on the cobra species. This may potentially influence the efficacy of cobra antivenom in specific use for venom neutralization.

Harnessing snake venom phospholipases A2 to novel approaches for overcoming antibiotic resistance

The emergence of antibiotic resistance drives an essential race against time to reveal new molecular structures capable of addressing this alarming global health problem. Snake venoms are natural catalogs of multifunctional toxins and privileged frameworks, which serve as potential templates for the inspiration of novel treatment strategies for combating antibiotic resistant bacteria. Phospholipases A₂ (PLA₂ s) are one of the main classes of antibacterial biomolecules, with recognized therapeutic value, found in these valuable secretions. Recently, a number of biomimetic oligopeptides based on small fragments of primary structure from PLA₂ toxins has emerged as a meaningful opportunity to overcome multidrug-resistant clinical isolates. Thus, this review will highlight the biochemical and structural properties of antibacterial PLA₂ s and peptides thereof, as well as their possible molecular mechanisms of action and key roles in development of effective therapeutic strategies. Chemical strategies possibly useful to convert antibacterial peptides from PLA₂ s to efficient drugs will be equally addressed.