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25 pages, 2812 KiB  
Article
Dual Proteomics Strategies to Dissect and Quantify the Components of Nine Medically Important African Snake Venoms
by Damien Redureau, Fernanda Gobbi Amorim, Thomas Crasset, Imre Berger, Christiane Schaffitzel, Stefanie Kate Menzies, Nicholas R. Casewell and Loïc Quinton
Toxins 2025, 17(5), 243; https://doi.org/10.3390/toxins17050243 - 13 May 2025
Viewed by 1156
Abstract
Snakebite envenoming constitutes a significant global health issue, particularly in Africa, where venomous species such as Echis vipers and Dendroaspis mambas pose substantial risks to human health. This study employs a standardized venomics workflow to comprehensively characterize and comparatively quantify the venom composition [...] Read more.
Snakebite envenoming constitutes a significant global health issue, particularly in Africa, where venomous species such as Echis vipers and Dendroaspis mambas pose substantial risks to human health. This study employs a standardized venomics workflow to comprehensively characterize and comparatively quantify the venom composition of nine medically relevant snake species chosen from among the deadliest in Africa. Utilizing shotgun venom proteomics and venom gland transcriptomics, we report detailed profiles of venom complexity, highlighting the relative abundance of dominant toxin families such as three-finger toxins and Kunitz-type proteins in Dendroaspis, and metalloproteinases and phospholipases A2 in Echis. We delineate here the relative abundance and structural diversity of venom components. Key to our proteomic approach is the implementation of Multi-Enzymatic Limited Digestion (MELD), which improved protein sequence coverage and enabled the identification of rare toxin families such as hyaluronidases and renin-like proteases, by multiplying the overlap of generated peptides and enhancing the characterization of both toxin and non-toxin components within the venoms. The culmination of these efforts resulted in the construction of a detailed toxin database, providing insights into the biological roles and potential therapeutic targets of venom proteins and peptides. The findings here compellingly validate the MELD technique, reinforcing its reproducibility as a valuable characterization approach applied to venomics. This research significantly advances our understanding of venom complexity in African snake species, including representatives of both Viperidae and Elapidae families. By elucidating venom composition and toxin profiles, our study paves the way for the development of targeted therapies aimed at mitigating the morbidity and mortality associated with snakebite envenoming globally. Full article
(This article belongs to the Special Issue Toxins: From the Wild to the Lab)
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21 pages, 3045 KiB  
Article
Why Are Some Snakes More Terrifying and What Is Behind the Fear?
by Daniel Frynta, Markéta Janovcová, Hassan Sh Abdirahman Elmi, Iveta Štolhoferová, Veronika Rudolfová, Kateřina Rexová, David Sommer, David Král, Daniel Alex Berti, Eva Landová and Petra Frýdlová
Animals 2025, 15(5), 731; https://doi.org/10.3390/ani15050731 - 4 Mar 2025
Cited by 1 | Viewed by 2436
Abstract
Snakes are stimuli inducing an ancestral fear response in humans and other primates. Certain snakes evoke more subjective fear than others. True vipers are high-fear-eliciting snakes for both African and European respondents. This can be explained by the evolutionary experience of human ancestors [...] Read more.
Snakes are stimuli inducing an ancestral fear response in humans and other primates. Certain snakes evoke more subjective fear than others. True vipers are high-fear-eliciting snakes for both African and European respondents. This can be explained by the evolutionary experience of human ancestors in Africa. The question arises as to how snakes living in the Americas and Australia, with which humans have no evolutionary experience, will be evaluated. While these snakes belong to broader taxonomic groups that have distant relatives in the Old World, they have evolved independently for tens of millions of years. We prepared a set of 32 pictures depicting eight American pit vipers, eight Australian elapids, eight constrictors, and eight colubrids and asked the respondents to rank these stimuli according to the fear these snakes evoke. Here, we show a high cross-cultural agreement between evaluations by African and European respondents. Snakes characterized by a robust body shape, such as American pit vipers, Australian death adders, pythons, and boas, were the most fear-evoking. The body width was the strongest predictor of evoked fear. The contribution of coloration and pattern of the stimulus to the fear response was not proved. This supports the view that the patterns of fear are not dependent on direct experience, but its underlying mechanisms are shared cross-culturally. Full article
(This article belongs to the Special Issue New Insights in Human-Animal Relationship: Emotions and Welfare)
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19 pages, 8260 KiB  
Article
Peptide Fraction from Naja mandalayensis Snake Venom Showed Neuroprotection Against Oxidative Stress in Hippocampal mHippoE-18 Cells but Not in Neuronal PC12 Cells
by Brenda R. Silva, Lais C. Mendes, Marcela B. Echeverry, Maria Aparecida Juliano, Emidio Beraldo-Neto and Carlos Alberto-Silva
Antioxidants 2025, 14(3), 277; https://doi.org/10.3390/antiox14030277 - 26 Feb 2025
Cited by 1 | Viewed by 858
Abstract
Functional characterization of peptide fraction (PF) from snake venom has provided novel opportunities to investigate possible neuroprotective compounds relevant to pharmaceuticals. This study was performed to investigate the PF-mediated neuroprotection obtained from Naja mandalayensis snake venom, a member of the Elapidae family, using [...] Read more.
Functional characterization of peptide fraction (PF) from snake venom has provided novel opportunities to investigate possible neuroprotective compounds relevant to pharmaceuticals. This study was performed to investigate the PF-mediated neuroprotection obtained from Naja mandalayensis snake venom, a member of the Elapidae family, using two neuronal cell lines, undifferentiated PC12 and differentiated mHippoE-18, in response to H2O2-induced oxidative stress. Cells were pre-treated for 4 h with PF (10, 1, 0.01, and 0.001 μg mL−1), and thereafter exposed to H2O2 (0.5 mmol L−1) for 20 h. Then, the oxidative stress markers and label-free differential proteome strategy were analyzed to understand the neuroprotective effects of PF. In PC12 cells, PF showed no neuroprotective effects against oxidative stress. In mHippoE-18 cells, PF at 0.01 and 0.001 μg mL−1 increased the viability and metabolism of cells against H2O2-induced neurotoxicity, reducing reactive oxygen species (ROS) generation. Interestingly, PF also exhibited a substantial reduction in baseline ROS levels compared to the control, indicating that PF could have compounds with antioxidant features. The comparative proteomic profiling identified 53 proteins with differential expression related to antioxidant action, catalysis, molecular function regulators, structural molecule activity, translation regulatory activity, ATP, and binding. The PF + H2O2 group indicated that protein expression is 6% upregulated, 4% downregulated, and 94% unchanged compared to the H2O2 group. Three significant proteins upregulated in the PF + H2O2 group, including elongation factor 2 (P58252), proteasome subunit alpha type (E9Q0X0), and E2 ubiquitin-conjugating enzyme (A0A338P786), suggested that PF-mediated neuroprotection happens through translational regulation and the degradation of defective proteins via the proteasome complex. Additionally, differential protein expression in PF changed the metabolism, protein synthesis, synaptic activity, and intracellular transport, suggesting that PF contains the rich mixture of bioactive peptides of interest pharmacologically. Overall, this study offers new opportunities for evaluating whether PF’s neuroprotective features in specific neuronal cells are maintained and to investigate neurodegenerative disease drug development processes. Full article
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21 pages, 5193 KiB  
Article
Proteomic Profiling of Venoms from Bungarus suzhenae and B. bungaroides: Enzymatic Activities and Toxicity Assessment
by Chenying Yang, Li Ding, Qiyi He, Xiya Chen, Haiting Zhu, Feng Chen, Wanzhou Yang, Yuexin Pan, Zhiyuan Tai, Wenhao Zhang, Zeyuan Yu, Zening Chen and Xiaodong Yu
Toxins 2024, 16(11), 494; https://doi.org/10.3390/toxins16110494 - 16 Nov 2024
Viewed by 2171
Abstract
Kraits are venomous snakes of the genus Bungarus from the family Elapidae. Their venom typically demonstrates neurotoxicity; however, the toxicity is significantly influenced by the snake’s species and geographical origin. Among the Bungarus species, Bungarus suzhenae and B. bungaroides have been poorly [...] Read more.
Kraits are venomous snakes of the genus Bungarus from the family Elapidae. Their venom typically demonstrates neurotoxicity; however, the toxicity is significantly influenced by the snake’s species and geographical origin. Among the Bungarus species, Bungarus suzhenae and B. bungaroides have been poorly studied, with little to no information available regarding their venom composition. In this study, a proteomic approach was employed using LC-MS/MS to identify proteins from trypsin-digested peptides. The analysis revealed 102 venom-related proteins from 18 distinct functional protein families in the venom of B. suzhenae, with the primary components being three-finger toxins (3-FTx, 25.84%), phospholipase A2 (PLA2, 40.29%), L-amino acid oxidase (LAAO, 10.33%), Kunitz-type serine protease inhibitors (KUN, 9.48%), and snake venom metalloproteinases (SVMPs, 6.13%). In the venom of B. bungaroides, 99 proteins from 17 families were identified, with primary components being 3-FTx (33.87%), PLA2 (37.91%), LAAO (4.21%), and KUN (16.60%). Enzymatic activity assays confirmed the presence of key venom enzymes. Additionally, the LD50 values for B. suzhenae and B. bungaroides were 0.0133 μg/g and 0.752 μg/g, respectively, providing a reference for toxicity studies of these two species. This research elucidates the proteomic differences in the venoms of these two species, offering a foundation for developing antivenoms and clinical treatments for envenomation. Full article
(This article belongs to the Special Issue Transcriptomic and Proteomic Study on Animal Venom: Looking Forward)
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18 pages, 2041 KiB  
Article
The Toxin Diversity, Cytotoxicity, and Enzymatic Activity of Cape Cobra (Naja nivea) Venom
by Tim Lüddecke, Ignazio Avella, Maik Damm, Lennart Schulte, Johanna Eichberg, Kornelia Hardes, Susanne Schiffmann, Marina Henke, Thomas Timm, Günter Lochnit and Andreas Vilcinskas
Toxins 2024, 16(10), 438; https://doi.org/10.3390/toxins16100438 - 11 Oct 2024
Cited by 1 | Viewed by 2433
Abstract
“True” cobras (genus Naja) are among the venomous snakes most frequently involved in snakebite accidents in Africa and Asia. The Cape cobra (Naja nivea) is one of the African cobras of highest medical importance, but much remains to be learned [...] Read more.
“True” cobras (genus Naja) are among the venomous snakes most frequently involved in snakebite accidents in Africa and Asia. The Cape cobra (Naja nivea) is one of the African cobras of highest medical importance, but much remains to be learned about its venom. Here, we used a shotgun proteomics approach to better understand the qualitative composition of N. nivea venom and tested its cytotoxicity and protease activity as well as its effect on intracellular Ca2+ release and NO synthesis. We identified 156 venom components representing 17 protein families, with the dominant ones being three-finger toxins, mostly of the short-chain type. Two-thirds of the three-finger toxin entries identified were assigned as cytotoxins, while the remainder were categorized as neurotoxins, including short-chain, long-chain, and ancestral three-finger toxins. We also identified snake venom metalloproteinases and members of CRISP, l-amino acid oxidase, and other families. Protease activity and its effect on intracellular Ca2+ release and NO synthesis were low. Phospholipase A2 activity was surprisingly high, despite this toxin family being marginally recovered in the analyzed venom. Cytotoxicity was relevant only at higher venom concentrations, with macrophage and neuroblastoma cell lines showing the lowest viability. These results are in line with the predominantly neurotoxic envenomation symptoms caused by Cape cobra bites. The present overview of the qualitatively complex and functionally intriguing venom of N. nivea may provide insights into the pathobiochemistry of this species’ venom. Full article
(This article belongs to the Section Animal Venoms)
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21 pages, 3252 KiB  
Article
Identification and Characterization of Novel Serpentoviruses in Viperid and Elapid Snakes
by Steven B. Tillis, Sarah B. Chaney, Esther E. V. Crouch, Donal Boyer, Kevin Torregrosa, Avishai D. Shuter, Anibal Armendaris, April L. Childress, Denise McAloose, Jean A. Paré, Robert J. Ossiboff and Kenneth J. Conley
Viruses 2024, 16(9), 1477; https://doi.org/10.3390/v16091477 - 17 Sep 2024
Viewed by 1876
Abstract
Viruses in the subfamily Serpentovirinae (order Nidovirales, family Tobaniviridae) can cause significant morbidity and mortality in captive snakes, but documented infections have been limited to snakes of the Boidae, Colubridae, Homalopsidae, and Pythonidae families. Infections can either be [...] Read more.
Viruses in the subfamily Serpentovirinae (order Nidovirales, family Tobaniviridae) can cause significant morbidity and mortality in captive snakes, but documented infections have been limited to snakes of the Boidae, Colubridae, Homalopsidae, and Pythonidae families. Infections can either be subclinical or associated with oral and/or respiratory disease. Beginning in June 2019, a population of over 150 confiscated snakes was screened for serpentovirus as part of a quarantine disease investigation. Antemortem oropharyngeal swabs or lung tissue collected postmortem were screened for serpentovirus by PCR, and 92/165 (56.0%) of snakes tested were positive for serpentovirus. Serpentoviruses were detected in fourteen species of Viperidae native to Asia, Africa, and South America and a single species of Elapidae native to Australia. When present, clinical signs included thin body condition, abnormal behavior or breathing, stomatitis, and/or mortality. Postmortem findings included variably severe inflammation, necrosis, and/or epithelial proliferation throughout the respiratory and upper gastrointestinal tracts. Genetic characterization of the detected serpentoviruses identified four unique viral clades phylogenetically distinct from recognized serpentovirus genera. Pairwise uncorrected distance analysis supported the phylogenetic analysis and indicated that the viper serpentoviruses likely represent the first members of a novel genus in the subfamily Serpentovirinae. The reported findings represent the first documentation of serpentoviruses in venomous snakes (Viperidae and Elapidae), greatly expanding the susceptible host range for these viruses and highlighting the importance of serpentovirus screening in all captive snake populations. Full article
(This article belongs to the Special Issue Virus Discovery, Classification and Characterization)
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16 pages, 3236 KiB  
Article
Unveiling Novel Kunitz- and Waprin-Type Toxins in the Micrurus mipartitus Coral Snake Venom Gland: An In Silico Transcriptome Analysis
by Mónica Saldarriaga-Córdoba, Claudia Clavero-León, Paola Rey-Suarez, Vitelbina Nuñez-Rangel, Ruben Avendaño-Herrera, Stefany Solano-González and Juan F. Alzate
Toxins 2024, 16(5), 224; https://doi.org/10.3390/toxins16050224 - 11 May 2024
Cited by 3 | Viewed by 2212
Abstract
Kunitz-type peptide expression has been described in the venom of snakes of the Viperidae, Elapidae and Colubridae families. This work aimed to identify these peptides in the venom gland transcriptome of the coral snake Micrurus mipartitus. Transcriptomic analysis revealed a high diversity [...] Read more.
Kunitz-type peptide expression has been described in the venom of snakes of the Viperidae, Elapidae and Colubridae families. This work aimed to identify these peptides in the venom gland transcriptome of the coral snake Micrurus mipartitus. Transcriptomic analysis revealed a high diversity of venom-associated Kunitz serine protease inhibitor proteins (KSPIs). A total of eight copies of KSPIs were predicted and grouped into four distinctive types, including short KSPI, long KSPI, Kunitz–Waprin (Ku-WAP) proteins, and a multi-domain Kunitz-type protein. From these, one short KSPI showed high identity with Micrurus tener and Austrelaps superbus. The long KSPI group exhibited similarity within the Micrurus genus and showed homology with various elapid snakes and even with the colubrid Pantherophis guttatus. A third group suggested the presence of Kunitz domains in addition to a whey-acidic-protein-type four-disulfide core domain. Finally, the fourth group corresponded to a transcript copy with a putative 511 amino acid protein, formerly annotated as KSPI, which UniProt classified as SPINT1. In conclusion, this study showed the diversity of Kunitz-type proteins expressed in the venom gland transcriptome of M. mipartitus. Full article
(This article belongs to the Special Issue Transcriptomic and Proteomic Study on Animal Venom: Looking Forward)
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25 pages, 6998 KiB  
Article
The Cloning and Characterization of a Three-Finger Toxin Homolog (NXH8) from the Coralsnake Micrurus corallinus That Interacts with Skeletal Muscle Nicotinic Acetylcholine Receptors
by Henrique Roman-Ramos, Álvaro R. B. Prieto-da-Silva, Humberto Dellê, Rafael S. Floriano, Lourdes Dias, Stephen Hyslop, Raphael Schezaro-Ramos, Denis Servent, Gilles Mourier, Jéssica Lopes de Oliveira, Douglas Edgard Lemes, Letícia V. Costa-Lotufo, Jane S. Oliveira, Milene Cristina Menezes, Regina P. Markus and Paulo Lee Ho
Toxins 2024, 16(4), 164; https://doi.org/10.3390/toxins16040164 - 22 Mar 2024
Cited by 1 | Viewed by 2260
Abstract
Coralsnakes (Micrurus spp.) are the only elapids found throughout the Americas. They are recognized for their highly neurotoxic venom, which is comprised of a wide variety of toxins, including the stable, low-mass toxins known as three-finger toxins (3FTx). Due to difficulties in [...] Read more.
Coralsnakes (Micrurus spp.) are the only elapids found throughout the Americas. They are recognized for their highly neurotoxic venom, which is comprised of a wide variety of toxins, including the stable, low-mass toxins known as three-finger toxins (3FTx). Due to difficulties in venom extraction and availability, research on coralsnake venoms is still very limited when compared to that of other Elapidae snakes like cobras, kraits, and mambas. In this study, two previously described 3FTx from the venom of M. corallinus, NXH1 (3SOC1_MICCO), and NXH8 (3NO48_MICCO) were characterized. Using in silico, in vitro, and ex vivo experiments, the biological activities of these toxins were predicted and evaluated. The results showed that only NXH8 was capable of binding to skeletal muscle cells and modulating the activity of nAChRs in nerve–diaphragm preparations. These effects were antagonized by anti-rNXH8 or antielapidic sera. Sequence analysis revealed that the NXH1 toxin possesses eight cysteine residues and four disulfide bonds, while the NXH8 toxin has a primary structure similar to that of non-conventional 3FTx, with an additional disulfide bond on the first loop. These findings add more information related to the structural diversity present within the 3FTx class, while expanding our understanding of the mechanisms of the toxicity of this coralsnake venom and opening new perspectives for developing more effective therapeutic interventions. Full article
(This article belongs to the Section Animal Venoms)
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12 pages, 2418 KiB  
Article
One-Step Affinity Purification of Leucine-Rich α2-Glycoproteins from Snake Sera and Characterization of Their Phospholipase A2-Inhibitory Activities as β-Type Phospholipase A2 Inhibitors
by Ryoichi Shirai, Kana Shibata, Shinobu Fujii, Rikiro Fukunaga and Seiji Inoue
Toxins 2024, 16(3), 126; https://doi.org/10.3390/toxins16030126 - 1 Mar 2024
Cited by 1 | Viewed by 1979
Abstract
Snakes contain three types of phospholipase A2 (PLA2)-inhibitory proteins in their blood, PLIα, β, and γ, which protect them from their own venom, PLA2. PLIβ is the snake ortholog of leucine-rich α2 glycoprotein (LRG). Since autologous cytochrome [...] Read more.
Snakes contain three types of phospholipase A2 (PLA2)-inhibitory proteins in their blood, PLIα, β, and γ, which protect them from their own venom, PLA2. PLIβ is the snake ortholog of leucine-rich α2 glycoprotein (LRG). Since autologous cytochrome c (Cyt c) serves as an endogenous ligand for LRG, in this study, we purified snake LRGs from various snake serum samples using Cyt c affinity chromatography. All purified snake LRGs were found to be dimers linked by disulfide bonds. Laticauda semifasciata and Naja kaouthia LRGs showed no inhibitory activity against L. semifasciata PLA2 and weak inhibitory activity against Gloydius brevicauda basic PLA2. Elaphe climacophora PLIβ had weaker inhibitory activity against G. brevicauda basic PLA2 than G. brevicauda and Elaphe quadrivirgata PLIs, which are abundant in blood and known to neutralize G. brevicauda basic PLA2. Protobothrops flavoviridis LRG showed no inhibitory activity against basic venom PLA2, PL-X, or G. brevicauda basic PLA2. Binding analysis of P. flavoviridis LRG using surface plasmon resonance showed very strong binding to snake Cyt c, followed by that to horse Cyt c, weak binding to yeast Cyt c, and no binding to P. flavoviridis PL-X or BPI/II. We also deduced the amino acid sequences of L. semifasciata and P. flavoviridis LRG by means of cDNA sequencing and compared them with those of other known sequences of PLIs and LRGs. This study concluded that snake LRG can potentially inhibit basic PLA2, but, whether it actually functions as a PLA2-inhibitory protein, PLIβ, depends on the snake. Full article
(This article belongs to the Special Issue Snake Venom: Toxicology and Associated Countermeasures)
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18 pages, 4636 KiB  
Systematic Review
Knowledge about Snake Venoms and Toxins from Colombia: A Systematic Review
by Jaime Andrés Pereañez, Lina María Preciado and Paola Rey-Suárez
Toxins 2023, 15(11), 658; https://doi.org/10.3390/toxins15110658 - 15 Nov 2023
Cited by 3 | Viewed by 4023
Abstract
Colombia encompasses three mountain ranges that divide the country into five natural regions: Andes, Pacific, Caribbean, Amazon, and Orinoquia. These regions offer an impressive range of climates, altitudes, and landscapes, which lead to a high snake biodiversity. Of the almost 300 snake species [...] Read more.
Colombia encompasses three mountain ranges that divide the country into five natural regions: Andes, Pacific, Caribbean, Amazon, and Orinoquia. These regions offer an impressive range of climates, altitudes, and landscapes, which lead to a high snake biodiversity. Of the almost 300 snake species reported in Colombia, nearly 50 are categorized as venomous. This high diversity of species contrasts with the small number of studies to characterize their venom compositions and natural history in the different ecoregions. This work reviews the available information about the venom composition, isolated toxins, and potential applications of snake species found in Colombia. Data compilation was conducted according to the PRISMA guidelines, and the systematic literature search was carried out in Pubmed/MEDLINE. Venom proteomes from nine Viperidae and three Elapidae species have been described using quantitative analytical strategies. In addition, venoms of three Colubridae species have been studied. Bioactivities reported for some of the venoms or isolated components—such as antibacterial, cytotoxicity on tumoral cell lines, and antiplasmodial properties—may be of interest to develop potential applications. Overall, this review indicates that, despite recent progress in the characterization of venoms from several Colombian snakes, it is necessary to perform further studies on the many species whose venoms remain essentially unexplored, especially those of the poorly known genus Micrurus. Full article
(This article belongs to the Section Animal Venoms)
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16 pages, 2115 KiB  
Article
Evolution of Three-Finger Toxin Genes in Neotropical Colubrine Snakes (Colubridae)
by Kristy Srodawa, Peter A. Cerda, Alison R. Davis Rabosky and Jenna M. Crowe-Riddell
Toxins 2023, 15(9), 523; https://doi.org/10.3390/toxins15090523 - 25 Aug 2023
Cited by 3 | Viewed by 2765
Abstract
Snake venom research has historically focused on front-fanged species (Viperidae and Elapidae), limiting our knowledge of venom evolution in rear-fanged snakes across their ecologically diverse phylogeny. Three-finger toxins (3FTxs) are a known neurotoxic component in the venoms of some rear-fanged snakes (Colubridae: Colubrinae), [...] Read more.
Snake venom research has historically focused on front-fanged species (Viperidae and Elapidae), limiting our knowledge of venom evolution in rear-fanged snakes across their ecologically diverse phylogeny. Three-finger toxins (3FTxs) are a known neurotoxic component in the venoms of some rear-fanged snakes (Colubridae: Colubrinae), but it is unclear how prevalent 3FTxs are both in expression within venom glands and more broadly among colubrine species. Here, we used a transcriptomic approach to characterize the venom expression profiles of four species of colubrine snakes from the Neotropics that were dominated by 3FTx expression (in the genera Chironius, Oxybelis, Rhinobothryum, and Spilotes). By reconstructing the gene trees of 3FTxs, we found evidence of putative novel heterodimers in the sequences of Chironius multiventris and Oxybelis aeneus, revealing an instance of parallel evolution of this structural change in 3FTxs among rear-fanged colubrine snakes. We also found positive selection at sites within structural loops or “fingers” of 3FTxs, indicating these areas may be key binding sites that interact with prey target molecules. Overall, our results highlight the importance of exploring the venoms of understudied species in reconstructing the full evolutionary history of toxins across the tree of life. Full article
(This article belongs to the Special Issue Venom Genes and Genomes of Venomous Animals: Evolution and Variation)
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9 pages, 1445 KiB  
Article
Comparative Analysis of Alpha-1 Orthosteric-Site Binding by a Clade of Central American Pit Vipers (Genera Atropoides, Cerrophidion, Metlapilcoatlus, and Porthidium)
by Lee Jones, Callum Waite, Edgar Neri-Castro and Bryan G. Fry
Toxins 2023, 15(8), 487; https://doi.org/10.3390/toxins15080487 - 2 Aug 2023
Cited by 4 | Viewed by 1778
Abstract
The distribution and relative potency of post-synaptic neurotoxic activity within Crotalinae venoms has been the subject of less investigation in comparison with Elapidae snake venoms. No previous studies have investigated post-synaptic neurotoxic activity within the Atropoides, Metlapilcoatlus, Cerrophidion, and Porthidium [...] Read more.
The distribution and relative potency of post-synaptic neurotoxic activity within Crotalinae venoms has been the subject of less investigation in comparison with Elapidae snake venoms. No previous studies have investigated post-synaptic neurotoxic activity within the Atropoides, Metlapilcoatlus, Cerrophidion, and Porthidium clade. Given the specificity of neurotoxins to relevant prey types, we aimed to uncover any activity present within this clade of snakes that may have been overlooked due to lower potency upon humans and thus not appearing as a clinical feature. Using biolayer interferometry, we assessed the relative binding of crude venoms to amphibian, lizard, bird, rodent and human α-1 nAChR orthosteric sites. We report potent alpha-1 orthosteric site binding in venoms from Atropoides picadoi, Metlapilcoatlus occiduus, M. olmec, M. mexicanus, M. nummifer. Lower levels of binding, but still notable, were evident for Cerrophidion godmani, C. tzotzilorum and C. wilsoni venoms. No activity was observed for Porthidium venoms, which is consistent with significant alpha-1 orthosteric site neurotoxicity being a trait that was amplified in the last common ancestor of Atropoides/Cerrophidion/Metlapilcoatlus subsequent to the split by Porthidium. We also observed potent taxon-selective activity, with strong selection for non-mammalian targets (amphibian, lizard, and bird). As these are poorly studied snakes, much of what is known about them is from clinical reports. The lack of affinity towards mammalian targets may explain the knowledge gap in neurotoxic activity within these species, since symptoms would not appear in bite reports. This study reports novel venom activity, which was previously unreported, indicating toxins that bind to post-synaptic receptors may be more widespread in pit vipers than previously considered. While these effects appear to not be clinically significant due to lineage-specific effects, they are of significant evolutionary novelty and of biodiscovery interest. This work sets the stage for future research directions, such as the use of in vitro and in vivo models to determine whether the alpha-1 orthosteric site binding observed within this study confers neurotoxic venom activity. Full article
(This article belongs to the Special Issue Snakebite and Clinical Toxinology)
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23 pages, 19341 KiB  
Article
Assessing the Efficacy of Monovalent and Commercialized Antivenoms for Neutralizing Moroccan Cobra Naja haje Venom: A Comparative Study
by Soukaina Khourcha, Ines Hilal, Iatimad Elbejjaj, Mehdi Karkouri, Amal Safi, Abdelaziz Hmyene and Naoual Oukkache
Trop. Med. Infect. Dis. 2023, 8(6), 304; https://doi.org/10.3390/tropicalmed8060304 - 2 Jun 2023
Cited by 8 | Viewed by 3420
Abstract
In Morocco, eight species of venomous snakes belonging to the Viperidae and Elapidae families are responsible for severe envenomation cases. The species from the Elapidae family is only represented by the medically relevant cobra Naja haje, which is widely distributed in North [...] Read more.
In Morocco, eight species of venomous snakes belonging to the Viperidae and Elapidae families are responsible for severe envenomation cases. The species from the Elapidae family is only represented by the medically relevant cobra Naja haje, which is widely distributed in North Africa. However, there is little information on the systemic effects of Moroccan cobra venom on vital organs due to regional variations. It has been demonstrated that the venom of Naja haje from Egypt causes hemorrhage, while the venom of the Moroccan cobra is neurotoxic and devoid of systemic bleeding. This variability is known to significantly influence treatment efficacy against Naja haje cobra bites in the Middle East. In this study, we examined the pathophysiological mechanisms responsible for the lethality induced by Naja haje venom, as well as the evaluation of the neutralizing capacity of two antivenoms; the monospecific antivenom made for Naja haje only and the antivenom marketed in the Middle East and North Africa. We first determined the toxicity of Naja haje venom by LD50 test, then compared the neutralizing capacity of the two antivenoms studied by determining the ED50. We also performed histological analysis on Swiss mice envenomed and treated with these antivenoms to observe signs of cobra venom envenomation and the degree of reduction of induced systemic alterations. The results showed significant differences between both antivenoms in terms of neutralization. The monospecific antivenom was four times more effective than the marketed antivenom. These results were confirmed by a histological study, which showed that monospecific antivenoms neutralized severe signs of mortality, such as congestion of blood vessels in the heart and kidneys, pulmonary and renal edema, cytoplasmic vacuolization of hepatocytes in the liver, and infiltration of inflammatory cells in the brain and spleen. However, the polyvalent antivenom failed to protect all severe lesions induced by Naja haje venom in mice. These findings highlight the negative impact of geographic variation on the effectiveness of conventional antivenom therapy and confirm the need for a specific Naja haje antivenom for the effective treatment of cobra envenomation in Morocco. Full article
(This article belongs to the Special Issue Treatment Strategies for Toxicity Caused by Venomous Animals)
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15 pages, 1860 KiB  
Article
Next-Generation Sequencing for Venomics: Application of Multi-Enzymatic Limited Digestion for Inventorying the Snake Venom Arsenal
by Fernanda Gobbi Amorim, Damien Redureau, Thomas Crasset, Lou Freuville, Dominique Baiwir, Gabriel Mazzucchelli, Stefanie K. Menzies, Nicholas R. Casewell and Loïc Quinton
Toxins 2023, 15(6), 357; https://doi.org/10.3390/toxins15060357 - 25 May 2023
Cited by 7 | Viewed by 3433
Abstract
To improve the characterization of snake venom protein profiles, we report the application of a new generation of proteomic methodology to deeply characterize complex protein mixtures. The new approach, combining a synergic multi-enzymatic and a time-limited digestion (MELD), is a versatile and straightforward [...] Read more.
To improve the characterization of snake venom protein profiles, we report the application of a new generation of proteomic methodology to deeply characterize complex protein mixtures. The new approach, combining a synergic multi-enzymatic and a time-limited digestion (MELD), is a versatile and straightforward protocol previously developed by our group. The higher number of overlapping peptides generated during MELD increases the quality of downstream peptide sequencing and of protein identification. In this context, this work aims at applying the MELD strategy to a venomics purpose for the first time, and especially for the characterization of snake venoms. We used four venoms as the test models for this proof of concept: two Elapidae (Dendroaspis polylepis and Naja naja) and two Viperidae (Bitis arietans and Echis ocellatus). Each venom was reduced and alkylated before being submitted to two different protocols: the classical bottom-up proteomics strategy including a digestion step with trypsin only, or MELD, which combines the activities of trypsin, Glu-C and chymotrypsin with a limited digestion approach. The resulting samples were then injected on an M-Class chromatographic system, and hyphenated to a Q-Exactive Mass Spectrometer. Toxins and protein identification were performed by Peaks Studio X+. The results show that MELD considerably improves the number of sequenced (de novo) peptides and identified peptides from protein databases, leading to the unambiguous identification of a greater number of toxins and proteins. For each venom, MELD was successful, not only in terms of the identification of the major toxins (increasing of sequence coverage), but also concerning the less abundant cellular components (identification of new groups of proteins). In light of these results, MELD represents a credible methodology to be applied as the next generation of proteomics approaches dedicated to venomic analysis. It may open new perspectives for the sequencing and inventorying of the venom arsenal and should expand global knowledge about venom composition. Full article
(This article belongs to the Special Issue Omics Approaches to Study Toxins)
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Quid Pro Quo: A Documented Case of Cannibalism in the Red-Bellied Black Snake Pseudechis porphyriacus in Lamington (Queensland, Australia)
by Tim Lüddecke
Diversity 2023, 15(5), 610; https://doi.org/10.3390/d15050610 - 29 Apr 2023
Cited by 1 | Viewed by 2062
Abstract
The red-bellied black snake (Pseudechis porphyriacus) is a member of the Elapidae family and is distributed on the east coast of Australia. The species is known to feed on a variety of ectothermic prey, including frogs and lizards. It is also [...] Read more.
The red-bellied black snake (Pseudechis porphyriacus) is a member of the Elapidae family and is distributed on the east coast of Australia. The species is known to feed on a variety of ectothermic prey, including frogs and lizards. It is also known to be ophiophagous (snake-feeding), and stomach-content analyses suggest that P. porphyriacus also exhibits cannibalistic behavior, yet this extreme case of ophiophagy has rarely been documented. Here, a case of cannibalism in P. porphyriacus, which was observed in Lamington (Queensland, Australia), has been photographically documented and is described. Full article
(This article belongs to the Special Issue Ecology, Systematics and Biodiversity of Reptiles)
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