Venom Fractions Research Articles

Interrogating stonefish venom: small molecules present in envenomation caused by Synanceia spp.

The stonefish Synanceia verrucosa and Synanceia horrida are arguably the most venomous fish species on earth and the culprits of severe stings in humans globally. Investigation into the venoms of these two species has mainly focused on protein composition, in an attempt to identify the most medically relevant proteins, such as the lethal verrucotoxin and stonustoxin components. This study, however, focused on medically relevant small molecules, and through nuclear magnetic resonance, mass spectroscopy, and fractionation techniques, we discovered and identified the presence of three molecules new to stonefish venom, namely γ-aminobutyric acid (GABA), choline and 0-acetylcholine, and provide the first report of GABA identified in a fish venom. Analysis of the crude venoms on human nicotinic acetylcholine receptors (nAChRs) and a GABAA receptor (GABAAR) showed S. horrida venom could activate neuronal (α7) and adult muscle-type (α1β1δε) nAChRs, while both crude S. horrida and S. verrucosa venoms activated the GABAAR (α1β2γ2). Cytotoxicity studies in immunologically relevant cells (human PBMCs) indicated the venoms possess cell-specific cytotoxicity and analysis of the venom fractions on Na+ channel subtypes involved in pain showed no activity. This work highlights the need to further investigate the small molecules found in venoms to help understand the mechanistic pathways of clinical symptoms for improved treatment of sting victims, in addition to the discovery of potential drug leads.

Elucidation of Medusozoan (Jellyfish) Venom Constituent Activities Using Constellation Pharmacology.

Within the phylum Cnidaria, sea anemones (class Anthozoa) express a rich diversity of ion-channel peptide modulators with biomedical applications, but corollary discoveries from jellyfish (subphylum Medusozoa) are lacking. To bridge this gap, bioactivities of previously unexplored proteinaceous and small molecular weight (~15 kDa to 5 kDa) venom components were assessed in a mouse dorsal root ganglia (DRG) high-content calcium-imaging assay, known as constellation pharmacology. While the addition of crude venom led to nonspecific cell death and Fura-2 signal leakage due to pore-forming activity, purified small molecular weight fractions of venom demonstrated three main, concentration-dependent and reversible effects on defined heterogeneous cell types found in the primary cultures of mouse DRG. These three phenotypic responses are herein referred to as phenotype A, B and C: excitatory amplification (A) or inhibition (B) of KCl-induced calcium signals, and test compound-induced disturbances to baseline calcium levels (C). Most notably, certain Alatina alata venom fractions showed phenotype A effects in all DRG neurons; Physalia physalis and Chironex fleckeri fractions predominantly showed phenotype B effects in small- and medium-diameter neurons. Finally, specific Physalia physalis and Alatina alata venom components induced direct excitatory responses (phenotype C) in glial cells. These findings demonstrate a diversity of neuroactive compounds in jellyfish venom potentially targeting a constellation of ion channels and ligand-gated receptors with broad physiological implications.

Thermoregulation Effects of Phoneutria nigriventer Isolated Toxins in Rats.

Body temperature is primarily regulated by the hypothalamus, ensuring proper metabolic function. Envenomation by Phoneutria nigriventer can cause symptoms such as hypothermia, hyperthermia, sweating, and shivering, all related to thermoregulation. This study aims to analyze and identify components of the venom that affect thermoregulation and to evaluate possible mechanisms. Rats were used for thermoregulation analysis, venom fractionation by gel filtration and reverse-phase chromatography (C18), and sequencing by Edman degradation. The venom exhibited hypothermic effects in rats, while its fractions demonstrated both hypothermic (pool II) and hyperthermic (pool III) effects. Further separations of the pools with C18 identified specific peaks responsible for these effects. However, as the peaks were further purified, their effects became less significant. Tests on U87 human glioblastoma cells showed no toxicity. Sequencing of the most active peaks revealed masses similar to those of the Tachykinin and Ctenotoxin families, both known to act on the nervous system. The study concludes that molecules derived from venom can act synergistically or antagonistically. Additionally, toxins that affect thermoregulation are poorly studied and require further characterization. These toxins could potentially serve as sources for the development of new thermoregulatory drugs.

Neutralizing Nanobodies against Venoms from Naja haje Species Captured in North Africa.

Snakebite envenoming (SBE) remains a severely neglected public health issue, particularly affecting tropical and subtropical regions, with Africa experiencing an estimated 435,000 to 580,000 snakebites annually, leading to high morbidity and mortality rates, especially across Africa and Asia. Recognized as a Neglected Tropical Disease, SBE management is further complicated by the inadequate efficacy of current antivenom treatments. Of particular concern are cobras (Naja sp.), whose neurotoxins can induce rapid fatal respiratory paralysis. In this study, we investigate the potential of nanobodies as a promising next-generation of immunotherapeutics against cobra venoms. Through a dual strategy of the characterization of venom toxic fractions from cobras captured for the first time in Algeria and Tunisia biotopes, coupled with in vitro assays to evaluate their interactions with acetylcholine receptors, and subsequent immunization of dromedaries to produce specific nanobodies, we identified two lethal fractions, F5 and F6, from each venom, and selected five nanobodies with significant binding and neutralizing of 3DL50 (0.74 mg/kg). The combination of these nanobodies demonstrated a synergistic effect, reaching 100% neutralizing efficacy of 2DL50 lethal venom fraction (0.88 mg/kg) doses in mice. Additionally, our findings highlighted the complex mechanism of cobra venom action through the lethal synergism among its major toxins.

The development of a micro method that optimizes venom fractionation for proteomic analysis

The development of a micro method that optimizes venom fractionation for proteomic analysis

CTXP, The Major Cobra Toxin Peptide from Naja Naja Oxiana Venom; A Promising Target for Antivenom Agent Development.

Snakebite envenoming is a serious public health issue causing more than 135,000 annual deaths worldwide. Naja Naja Oxiana is one of the most clinically important venomous snakes in Iran and Central Asia. Conventional animal-derived polyclonal antibodies are the major treatment of snakebite envenoming. Characterization of venom components helps to pinpoint the toxic protein responsible for clinical manifestations in victims, which aids us in developing efficient antivenoms with minimal side effects. Therefore, the present study aimed to identify the major lethal protein of Naja Naja Oxiana by top-down proteomics. Venom proteomic profiling was performed using gel filtration (GF), reversed-phase (RP) chromatography, and intact mass spectrometry. The toxicity of GF-, and RP-eluted fractions was analyzed in BALB/c mice. The rabbit polyclonal antisera were produced against crude venom, GF fraction V (FV), and RP peak 1 (CTXP) and applied in neutralization assays. Toxicity studies in BALB/c identified FV as the major toxic fraction of venom. Subsequently, RP separation of FV resulted in eight peaks, of which peak 1, referred to as "CTXP" (cobra toxin peptide), was identified as the major lethal protein. In vivo neutralization assays using rabbit antisera showed that polyclonal antibodies raised against FV and CTXP are capable of neutralizing at least 2-LD50s of crude venom, FV, and CTXP in all tested mice. Surprisingly, the Anti-CTXP antibody could neutralize 8-LD50 of the CTXP peptide. These results identified CTXP (a 7 kDa peptide) as a potential target for the development of novel efficient antivenom agents.

F1 fraction isolated from Mesobuthus eupeus scorpion venom induces macrophage polarization toward M1 phenotype and exerts anti-tumoral effects on the CT26 tumor cell line

Scorpion venoms identified as agents with anti-tumor and anti-angiogenic features. Tumor microenvironment (TME) plays a pivotal role in the process of tumorigenesis, tumor development, and polarization of M2 phenotype tumor associated macrophages (TAMs). M2 polarized cells are associated with tumor growth, invasion, and metastasis. The fractionation process was performed by gel filtration chromatography on a Sephadex G50 column. To elucidate whether scorpion venom can alter macrophage polarization, we treated interleukin (IL)-4-polarized M2 cells with isolated fractions from Mesobuthus eupeus. Next, we evaluated the cytokine production and specific markers expression for M2 and M1 phenotype using enzyme linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (PCR), respectively. The phagocytic capacity of macrophages was also assessed. In addition, the migration assay and MTT analysis were performed to investigate the effects of reprogrammed macrophages on the CT-26 colon cancer cells. The results indicated that F1 fraction of venom significantly upregulated the levels and expression of M1-associated cytokines and markers, including tumor necrosis factor-alpha (TNF-α) (p < 0.001), IL-1 (p < 0.01), interferon regulatory factor 5 (IRF5) (p < 0.0001), induced nitric oxide synthase (iNOS) (p < 0.0001), and CD86 (p < 0.0001), and downregulated M2-related markers, including transforming growth factor-beta (TGF-β) (p < 0.05), IL-10 (p < 0.05), Fizz1 (p < 0.0001), arginase-1 (Arg-1) (p < 0.0001), and CD206 (p < 0.001). The macrophage phagocytic capacity was enhanced after treatment with F1 fraction (p < 0.01). Moreover, incubation of CT-26 cell line with conditioned media of F1-treated macrophages suppressed migration (p < 0.0001) and proliferation (p < 0.01) of tumor cells. In conclusion, our findings demonstrated the potential of Mesobuthus eupeus venom in M2-to-M1 macrophage polarization as a promising therapeutic approach against proliferation and metastasis of colon cancer cells.

A comparative study of the performance of E. coli and K. phaffii for expressing α-cobratoxin

Three-finger toxins (3FTxs) have traditionally been obtained via venom fractionation of whole venoms from snakes. This method often yields functional toxins, but it can be difficult to obtain pure isoforms, as it is challenging to separate the many different toxins with similar physicochemical properties that generally exist in many venoms. This issue can be circumvented via the use of recombinant expression. However, achieving the correct disulfide bond formation in recombinant toxins is challenging and requires extensive optimization of expression and purification methods to enhance stability and functionality. In this study, we investigated the expression of α-cobratoxin, a well-characterized 3FTx from the monocled cobra (Naja kaouthia), in three different expression systems, namely Escherichia coli BL21 (DE3) cells with the csCyDisCo plasmid, Escherichia coli SHuffle cells, and Komagataella phaffii (formerly known as Pichia pastoris). While none of the tested systems yielded α-cobratoxin identical to the variant isolated from whole venom, the His6-tagged α-cobratoxin expressed in K. phaffii exhibited a comparable secondary structure according to circular dichroism spectra and similar binding properties to the α7 subunit of the nicotinic acetylcholine receptor. The findings presented here illustrate the advantages and limitations of the different expression systems and can help guide researchers who wish to express 3FTxs.

Acute phase reactions in Daboia siamensis venom and fraction-induced acute kidney injury: the role of oxidative stress and inflammatory pathways in in vivo rabbit and ex vivo rabbit kidney models.

This study examines the direct nephrotoxic effects of Daboia siamensis venom (RVV) and venom fractions in in vivo and isolated perfused kidneys (IPK) to understand the role of inflammation pathways and susceptibility to oxidative stress in venom or fraction-induced acute renal failure. We administered RVV and its venom fractions (PLA2, MP, LAAO, and PDE) to rabbits in vivo and in the IPK model. We measured oxidative stress biomarkers (SOD, CAT, GSH, and MDA) in kidney tissue, as well as inflammatory cytokines (TNF-α, IL-1β, IFN-γ, IL-4, IL-5, and IL-10), MDA and GSH levels in plasma and urine. We also calculated fractional excretion (FE) for pro-/anti-inflammatory cytokines and oxidative stress biomarkers, including the ratios of pro-/anti-inflammatory cytokines in urine after envenomation. In both kidney models, significant increases in MDA, SOD, CAT, and GSH levels were observed in kidney tissues, along with elevated concentrations of MDA and GSH in plasma and urine after injecting RVV and venom fractions. Moreover, RVV injections led to progressive increases in FEMDA and decreases in FEGSH. The concentrations of IL-4, IL-5, IL-10, IFN-γ, and TNF-α in plasma increased in vivo, as well as in the urine of the IPK model, but not for IL-1β in both plasma and urine after RVV administrations. Urinary fractional excretion of TNF-α, IL-1β, IFN-γ, IL-4, IL-5, and IL-10 tended to decrease in vivo but showed elevated levels in the IPK model. A single RVV injection in vivo disrupted the balance of urinary cytokines, significantly reducing either the TNF-α/IL-10 ratio or the IFN-γ/IL-10 ratio. RVV induces renal tubular toxicity by increasing oxidative stress production and elevating inflammatory cytokines in urine. During the acute phase of acute kidney injury, the balance of urine cytokines shifts toward anti-inflammatory dominance within the first two hours post-RVV and venom fractions.

The Effects of the Fraction Isolated from Iranian Buthotus shach Scorpion Venom on Synaptic Plasticity, Learning, Memory, and Seizure Susceptibility.

Epilepsy, as a neurological disease, can be defined as frequent seizure attacks. Further, it affects many other aspects of patients' mental activities, such as learning and memory. Scorpion venoms have gained notice as compounds with potential antiepileptic properties. Among them, Buthotus schach (BS) is one of the Iranian scorpions studied by Aboutorabi et al., who fractionated, characterized, and tested this compound using electrophysiological techniques in brain slices (patch-clamp recording). In the present study, the fraction obtained from gel electrophoresis was investigated through behavioral and electrophysiological assays. At first, ventricular cannulation was performed in rats, and then the active fraction (i.e., F3), carbamazepine, and the vehicle were microinjected into the brain before seizure induction by the subcutaneous (SC) injection of pentylenetetrazol (PTZ). Seizure behaviors were scaled according to Racine stages. Memory and learning were evaluated using the Y-maze and passive avoidance tests. Other groups entered evoked field potential recording after microinjection and seizure induction. Population spike (PS) and field excitatory postsynaptic potential (fEPSP) were measured. The F3 fraction could prevent the fifth stage and postpone the third stage of seizure compared to the control (carbamazepine) group. There was no significant improvement in memory and learning in the group treated with the F3 fraction. Also, PS amplitude and fEPSP slope increased significantly, and long-term potentiation was successfully formed after the high-frequency stimulation of the performant pathway. Our results support the antiepileptic effects of the F3 fraction of BS venom, evidenced by behavioral and electrophysiological studies. However, the effects of this fraction on memory and learning were not in the same direction, suggesting the involvement of two different pathways.

Scorpion Venom as a Source of Antimicrobial Peptides: Overview of Biomolecule Separation, Analysis and Characterization Methods.

Scorpion venoms have long captivated scientific researchers, primarily due to the potency and specificity of the mechanism of action of their derived components. Among other molecules, these venoms contain highly active compounds, including antimicrobial peptides (AMPs) and ion channel-specific components that selectively target biological receptors with remarkable affinity. Some of these receptors have emerged as prime therapeutic targets for addressing various human pathologies, including cancer and infectious diseases, and have served as models for designing novel drugs. Consequently, extensive biochemical and proteomic investigations have focused on characterizing scorpion venoms. This review provides a comprehensive overview of the key methodologies used in the extraction, purification, analysis, and characterization of AMPs and other bioactive molecules present in scorpion venoms. Noteworthy techniques such as gel electrophoresis, reverse-phase high-performance liquid chromatography, size exclusion chromatography, and "omics" approaches are explored, along with various combinations of methods that enable bioassay-guided venom fractionation. Furthermore, this review presents four adapted proteomic workflows that lead to the comprehensive dissection of the scorpion venom proteome, with an emphasis on AMPs. These workflows differ based on whether the venom is pre-fractionated using separation techniques or is proteolytically digested directly before further proteomic analyses. Since the composition and functionality of scorpion venoms are species-specific, the selection and sequence of the techniques for venom analyses, including these workflows, should be tailored to the specific parameters of the study.

Toxins from Animal Venoms as a Potential Source of Antimalarials: A Comprehensive Review.

Malaria is an infectious disease caused by Plasmodium spp. and it is mainly transmitted to humans by female mosquitoes of the genus Anopheles. Malaria is an important global public health problem due to its high rates of morbidity and mortality. At present, drug therapies and vector control with insecticides are respectively the most commonly used methods for the treatment and control of malaria. However, several studies have shown the resistance of Plasmodium to drugs that are recommended for the treatment of malaria. In view of this, it is necessary to carry out studies to discover new antimalarial molecules as lead compounds for the development of new medicines. In this sense, in the last few decades, animal venoms have attracted attention as a potential source for new antimalarial molecules. Therefore, the aim of this review was to summarize animal venom toxins with antimalarial activity found in the literature. From this research, 50 isolated substances, 4 venom fractions and 7 venom extracts from animals such as anurans, spiders, scorpions, snakes, and bees were identified. These toxins act as inhibitors at different key points in the biological cycle of Plasmodium and may be important in the context of the resistance of Plasmodium to currently available antimalarial drugs.

The Predatory Stink Bug Arma custos (Hemiptera: Pentatomidae) Produces a Complex Proteinaceous Venom to Overcome Caterpillar Prey.

Predatory stink bugs capture prey by injecting salivary venom from their venom glands using specialized stylets. Understanding venom function has been impeded by a scarcity of knowledge of their venom composition. We therefore examined the proteinaceous components of the salivary venom of the predatory stink bug Arma custos (Fabricius, 1794) (Hemiptera: Pentatomidae). We used gland extracts and venoms from fifth-instar nymphs or adult females to perform shotgun proteomics combined with venom gland transcriptomics. We found that the venom of A. custos comprised a complex suite of over a hundred individual proteins, including oxidoreductases, transferases, hydrolases, ligases, protease inhibitors, and recognition, transport and binding proteins. Besides the uncharacterized proteins, hydrolases such as venom serine proteases, cathepsins, phospholipase A2, phosphatases, nucleases, alpha-amylases, and chitinases constitute the most abundant protein families. However, salivary proteins shared by and unique to other predatory heteropterans were not detected in the A. custos venom. Injection of the proteinaceous (>3 kDa) venom fraction of A. custos gland extracts or venom into its prey, the larvae of the oriental armyworm Mythimna separata (Walker, 1865), revealed insecticidal activity against lepidopterans. Our data expand the knowledge of heteropteran salivary proteins and suggest predatory asopine bugs as a novel source for bioinsecticides.

FIBRINOGEN-SPECIFIC PROTEASE IN THE Vipera renardi SNAKE VENOM

Aim. To search fibrinogenolytic enzymes among protein components of Vipera renardi snake venom. Methods. Venom of V. renardi as the lyophilized powder was supplied by Trypillia serpentarium. It was dissolved in 0.05 M Tris-HCl buffer pH 8.3 and fractionated on Superdex G-75 using FPLC system Acta Prime. Peaks were tested for their ability to directly cleave fibrinogen. Hydrolytic products were analyzed by SDS-PAGE. Enzyme-electrophoresis with fibrinogen co-polymerized in 12% polyacrylamide gel was used for the identification of protein that can cleave fibrinogen.. Results. Venom of V. renardi was fractionated on 4 fractions using size-exclusion chromatography. SDS-PAGE of fibrinogen hydrolysis products showed the presence of fibrinogen-specific protease in the 1st and 2nd fractions of venom. 2nd fraction was much more active and according to the data of enzyme electrophoresis contained protease with molecular mass 25 kDa. Conclusions. Fractionation of V. renardi snake venom allowed to detect a protease with apparent molecular mass 25 kDa that can cleave fibrinogen molecule.

An Assassin's Secret: Multifunctional Cytotoxic Compounds in the Predation Venom of the Assassin Bug Psytalla horrida (Reduviidae, Hemiptera).

Predatory assassin bugs produce venomous saliva that enables them to overwhelm, kill, and pre-digest large prey animals. Venom from the posterior main gland (PMG) of the African assassin bug Psytalla horrida has strong cytotoxic effects, but the responsible compounds are yet unknown. Using cation-exchange chromatography, we fractionated PMG extracts from P. horrida and screened the fractions for toxicity. Two venom fractions strongly affected insect cell viability, bacterial growth, erythrocyte integrity, and intracellular calcium levels in Drosophila melanogaster olfactory sensory neurons. LC-MS/MS analysis revealed that both fractions contained gelsolin, redulysins, S1 family peptidases, and proteins from the uncharacterized venom protein family 2. Synthetic peptides representing the putative lytic domain of redulysins had strong antimicrobial activity against Escherichia coli and/or Bacillus subtilis but only weak toxicity towards insect or mammalian cells, indicating a primary role in preventing the intake of microbial pathogens. In contrast, a recombinant venom protein family 2 protein significantly reduced insect cell viability but exhibited no antibacterial or hemolytic activity, suggesting that it plays a role in prey overwhelming and killing. The results of our study show that P. horrida secretes multiple cytotoxic compounds targeting different organisms to facilitate predation and antimicrobial defense.

Isolated Peptide from Spider Venom Modulates Dendritic Cells In Vitro: A Possible Application in Oncoimmunotherapy for Glioblastoma.

Dendritic cells (DCs) vaccine is a potential tool for oncoimmunotherapy. However, it is known that this therapeutic strategy has failed in solid tumors, making the development of immunoadjuvants highly relevant. Recently, we demonstrated that Phoneutria nigriventer spider venom (PnV) components are cytotoxic to glioblastoma (GB) and activate macrophages for an antitumor profile. However, the effects of these molecules on the adaptive immune response have not yet been evaluated. This work aimed to test PnV and its purified fractions in DCs in vitro. For this purpose, bone marrow precursors were collected from male C57BL6 mice, differentiated into DCs and treated with venom or PnV-isolated fractions (F1-molecules < 3 kDa, F2-3 to 10 kDa and F3->10 kDa), with or without costimulation with human GB lysate. The results showed that mainly F1 was able to activate DCs, increasing the activation-dependent surface marker (CD86) and cytokine release (IL-1β, TNF-α), in addition to inducing a typical morphology of mature DCs. From the F1 purification, a molecule named LW9 was the most effective, and mass spectrometry showed it to be a peptide. The present findings suggest that this molecule could be an immunoadjuvant with possible application in DC vaccines for the treatment of GB.

A proteomic overview of the major venom components from Tityus championi from Panama

In recent years, morbidity caused by scorpion sting of the species Tityus championi has increased in Panama. Therefore, the LD50 was determined by intravenous injection in 2.9 mg/kg and the venom of T. championi was separated using a HPLC system and their fractions were tested for biological activities in mice to identify the most toxic fractions to mammals. In addition, the venom fractions were also tested against invertebrates to look for insect-specific toxin peptides. The most toxic fractions were analyzed by MS/MS spectrometry. The primary structures of T. championi venom peptides with the most relevant activity were obtained, and the primary structure of one of most neurotoxic peptides was found at least in other four species of Tityus from Panama. This neurotoxin is quite important to be used as a protein target to be neutralized if developing antivenoms against the sting of this Panamanian scorpion or other relevant species of genera Tityus in the country.

Lipidomic profiling of the Brazilian yellow scorpion venom: new insights into inflammatory responses following Tityus serrulatus envenomation

ABSTRACT Due to the high prevalence and clinical relevance, scorpionism is a critical public health issue in several Brazilian regions. Tityus serrulatus, commonly known as the Brazilian yellow scorpion, is the most venomous genus found in Brazilian fauna and associated with severe clinical manifestations such as localized pain, hypertension, sweating, tachycardia and complex hyperinflammatory responses. In general, T. serrulatus venom contains a complex mixture of active compounds, including proteins, peptides, and amino acids. Although knowledge of the protein fractions of scorpion venom is available, venom lipid components are not yet comprehensively known. The aim of the present study was to determine and characterize the lipid constituents/profile of the T. serratus venom utilizing liquid chromatography coupled with high-resolution mass spectrometry. Lipid species (164 in total) belonging to 3 different lipid categories, glycerophospholipids, sphingolipids, and glycerolipids, were identified. A further search on MetaCore/MetaDrug platform, which is based upon a manually curated database of molecular interactions, molecular pathways, gene-disease associations, chemical metabolism, and toxicity information, exhibited several metabolic pathways for 24 of previously identified lipid species, including activation of nuclear factor kappa B and oxidative stress pathways. Further several bioactive compounds, such as plasmalogens, lyso-platelet-activating factors, and sphingomyelins, associated with systemic responses triggered by T. serrulatus envenomation were detected. Finally, lipidomic data presented provide advanced and valuable information to better comprehend the mechanisms underlying the complex pathophysiology induced by T. serrulatus envenomation.

Unraveling and profiling Tityus bahiensis venom: Biochemical analyses of the major toxins

Among the scorpions found in Brazil, Tityus bahiensis is one of the species that causes most of the reported human accidents. In spite of this important constatation, the venom composition description is not available in the literature. Thus, this venom remains not properly studied, segregating this particular species into an abandoned, forgotten condition.In the present study, chromatographic separation (RP-HPLC-C18) and proteomic analyses were employed to unravel the diversity, complexity, and proportional distribution of the main peptides and proteins found in the scorpion venom. Moreover, sequence analyses and the presence of new isoforms and toxins are discussed based on a database comparison with other Tityus toxins.Our results show the presence of a wide diversity of potassium and sodium channel toxins and enzymes, such as metallopeptidases and hyaluronidases, as previously described for other species. However, the current work also describes for the first time, at the protein level, phospholipase, angiotensin-converting enzyme, cysteine-rich proteins, serine peptidase inhibitors peptides, and antimicrobial peptides. Finally, thorough data analyses allowed the description of the venom toxins distribution regarding their diversity and relative quantity. SignificanceThe work presents the first Tityus bahiensis proteome. We have focused on describing the neurotoxin variability in terms of their isoforms/amino acid substitutions. Understanding the natural variations in the toxins' sequences is essential, once the affinity of these peptides to their respective receptors/ionic channels will vary depending on the specific peptide sequences. Moreover, the current study describes some proteins present in the venom, including enzymes being described for the first time in scorpion venoms, such as PLA2 and ACE. Moreover, we describe the individual relative quantity distribution for the different protein classes identified, as well as their variability in the T.bahiensis venom. Finally, this study also reports the development of a simple straightforward chromatographic method for scorpion venom fractionation.

Bactericidal Effects of Snake Venom Phospholipases A2: A Systematic Review and Analysis of Minimum Inhibitory Concentration

Background: Infections caused by multi-drug resistance (MDR) strains are potentially fatal public health issues worldwide that need pressing attention. Previous reports suggested using snake venom fractions as an effective alternative mechanism to the already available antibacterial drugs. In this study, we conducted a systematic review to analyze the bactericidal effects of snake venom phospholipases (PLA2s). Methods: From the beginning through 30 March 2022, we searched the PubMed and Embase databases in accordance with the most recent PRISMA recommendations. We also conducted a manual search to identify relevant reports to improve literature coverage. Results: A total of 24 studies were included based on the selection criteria to compile this review. Of them, 16 studies were obtained from the abovementioned databases and eight through manual searches. The other 8 studies were obtained through the references of the included studies. According to the review, we reported that some PLA2s showed more vigorous bactericidal activity on some Gram-negative and a moderate effect on Gram-negative and Gram-positive. Furthermore, we reported that the presence of p-bromophenacyl bromide (p-BPP) showed a significant decrease in enzymatic and associated antibacterial activities. Moreover, we observed that about 80% of the PLA2s reported in our systematic review study were those from the Viperidae family, whereas 20% came from the Elapidae family. Moreover, some variations were revealed in the current study regarding the mechanism of actions of the snake venom PLA2s (svPLA2s). Conclusion: This systematic review provides a comprehensive overview of the bactericidal effect of snake venom PLA2s and the analysis of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of PLA2s for bacterial strains. Varying bactericidal effects from various snake species and South American rattlesnakes were reported, presenting compelling concepts to the alternative search for therapies against bacterial resistance. Thus, further analysis of the bactericidal effects of other snake venoms PLA2s considering different strains is needed. Moreover, more data are needed to investigate other bacteria of public health priority using peptides and other purified snake toxins.