Search Results (112)

Spodoptera litura is a polyphagous lepidopteran pest with rapidly evolving insecticide resistance. Peptide toxins from venomous organisms, many stabilized by the inhibitor cystine knot motif, offer bioinsecticidal potential but show limited oral efficacy. Seven previously reported candidates were recombinantly produced in Pichia pastoris and screened against S. litura by injection and leaf-disc feeding bioassays, followed by whole-plant spray assays. The marine nemertean toxin nemertide α-1, designated A1, showed the strongest oral activity, with a median lethal concentration of 3.97 μg μL⁻¹. Conversely, the engineered spider-venom peptide U1-AGTX-Ta1b R9Q (T1) was most toxic by injection but showed no detectable oral activity, demonstrating that injection toxicity did not predict oral efficacy. High-cell-density fermentation yielded an estimated A1 titer of 1.20 g L⁻¹. Whole-plant foliar application of A1 showed concentration-dependent efficacy. Mortality reached 92.07% at 8 μg μL⁻¹, whereas lower concentrations suppressed larval growth, reducing the mean weight of surviving larvae by 41.55% and 67.58% at 1 and 2 μg μL⁻¹, respectively, and mitigated feeding damage. These findings extend the documented oral insecticidal spectrum of nemertide α-1 to S. litura and demonstrate whole-plant efficacy following foliar application, supporting its development as an active ingredient for foliar-applied peptide bioinsecticides. Full article

Background: Orientothele washanensis is a venomous spider with considerable ecological and scientific importance. Its venom, characterized by complex composition and ease of collection, serves as a valuable resource for the discovery of natural peptide drugs. Conventional wet-lab screening methods are limited by rigorous experimental conditions, high resource consumption, and long research cycles, which hinder the efficient identification of functional peptides from the venom gland transcriptome of this spider. Methods: To address these technical bottlenecks, this study developed a novel deep learning model named PepPI-DRN for peptide-protein interaction prediction. The model integrated a residual equivariant graph neural network, a residual 1-dimensional convolutional neural network, and a dual-modal attention mechanism by leveraging both sequence and structural features of peptides and proteins. Results: Results on an independent test set indicated that PepPI-DRN achieved the competitive or superior performance compared with state-of-the-art methods on multiple key evaluation metrics. Candidate peptides with high interaction probabilities against targets were obtained from the venom gland transcriptome of Orientothele washanensis. Furthermore, lead peptides with high binding strength and good structural stability were identified from candidate peptides by molecular docking, and molecular dynamics simulation. Conclusions: These results showed that the pipeline with PepPI-DRN, molecular docking and molecular dynamics simulation enabled efficient and reliable identification of lead peptides from the venom gland transcriptome of Orientothele washanensis, providing a robust and effective strategy for the discovery and development of natural peptide drugs from the spider venom. Full article

The LW-9 peptide was previously identified through screening of purified molecules from the venom of the spider Phoneutria nigriventer and has been described as an immunomodulatory compound with potential application in cancer therapy. The molecule was biochemically characterized and subjected to in silico analyses to evaluate its toxicity and efficacy profiles. LW-9 exhibits a molecular mass of 1235.522 Da and the amino acid sequence PyrKKDRFLGLM-CONH₂. Secondary and tertiary structures were modeled using computational approaches. The results indicated low permeability across biological membranes, including the blood–brain barrier. In silico predictions further suggested that LW-9 is neither carcinogenic nor mutagenic; however, it may act as a potent inhibitor of the CYP3A4 enzyme, raising concerns regarding potential drug–drug interactions. Overall, LW-9 shows promise as an immunomodulatory agent for cancer applications, while its pharmacokinetic properties and possible interactions with other drugs continue to be investigated. Full article

The antimicrobial resistance of Acinetobacter baumannii necessitates the development of novel therapeutic strategies targeting essential enzymes such as Undecaprenyl Pyrophosphate Phosphatase (UppP). This study explored spider venom peptides in silico as potential allosteric inhibitors of A. baumannii UppP. A systematic literature review was conducted to select eight α-helical peptides with reported anti-A. baumannii activity, followed by their computational physicochemical characterization. Three-dimensional models of A. baumannii UppP and the candidate peptides were generated, and a putative allosteric binding site was validated through molecular docking of a known inhibitor of the BacA homolog. The eight peptides were subsequently docked to this validated site using HADDOCK. Results revealed variable binding affinities; peptides LC-AMP-I1, Lycosin-II, and GK37 exhibited the most favorable HADDOCK scores and extensive interaction networks, consistent with their reported high antimicrobial potency. Other candidates, notably Lt-MAP2, showed low binding affinity but high predicted synergistic potential. These findings identify promising spider venom peptide candidates, suggesting dual (membrane disruption/UppP inhibition) or synergistic mechanisms of action, and validate UppP as a viable pharmacological target for peptide-based inhibitors. Full article

Huwentoxin-XI (HWTX-XI) is a 55-amino acid peptide belonging to the family of spider Kuntiz-type toxins (KTTs), isolated from the venom of the Chinese tarantula Cyriopagopus schmidti. Under whole-cell voltage-clamp conditions, HWTX-XI was found to block Kv1.1 potassium channels but had no effect on other potassium channel subunits (Kv1.4, Kv2.1, Kv3.1 and Kv4.2), sodium channels or calcium channels. In the present study, it was found that the substitution of Tyr379 by the valine in the filter region significantly decreased the affinity of toxin HWTX-XI by about 90-fold, indicating that the Kv1.1 filter region is a critical determinant of HWTX-XI potassium channel activity. After intrathecal or intraplantar injections, HWTX-XI decreased the mechanical nociceptive threshold (hyperalgesia) for a long-lasting period. HWTX-XI also significantly increased the firing frequency in mouse DRG neurons. The novel function of HWTX-XI makes it a new tool for studying the relationship between spider toxins and Kv1.1 channels and suggests that Kv1.1 channels might be a novel potential target for preventing and/or treating neuropathic pain. Full article

Fireflies, which predominantly prey on various mollusks such as small snails and slugs, are renowned for their unique bioluminescence. Firefly toxins—particularly Lucibufagins (LBGs), which target the α-subunit of the sodium–potassium pump protein (ATPα)—play a crucial role in their survival strategies. However, the types and functions of venom proteins in fireflies remain to be elucidated. In this study, transcriptome sequencing was employed on the larval head of Pyrocoelia analis larvae, through which transcripts encoding several putative venom proteins were identified, including phospholipase A1/A2, 5′-nucleotidase, cysteine-rich secretory proteins (CRISPs), and insulin-like peptides. Structural comparison revealed that venom proteins in fireflies exhibited high sequence and structural similarity with venom proteins from various venomous animals (e.g., snakes, scorpions, spiders, and cone snails). These venom proteins may exert synergistic effects through multiple mechanisms, such as neurotoxicity, metabolic interference, and cytotoxicity, thereby playing an essential role in mollusk predation and defense against predators. Our study not only analyzes the complexity and uniqueness of Py. analis venom proteins but also provides a robust foundation for further exploration of the ecological adaptability and evolutionary mechanisms of these venom proteins. Full article

Most respiratory diseases are driven by excessive airway inflammation and oxidative stress, yet current therapies often lack durable efficacy or are unsafe. Host-defense peptides, commonly enriched in animal venoms, offer diverse, target-selective scaffolds for new therapeutics. In this study, we aimed to discover a novel bioactive peptide with therapeutic potential on respiratory tract damage by utilizing Nephila clavata venom gland transcriptome. Using in silico analysis and machine learning-based functional prediction, we designed a peptide, NC-CV, expected to have dual anti-inflammatory and antioxidant activities with low cytotoxicity. In experimental validation, NC-CV improved human bronchial epithelial BEAS-2B cell viability under lipopolysaccharide (LPS) exposure while reducing LPS-induced pro-inflammatory cytokine expression and intracellular reactive oxygen species (ROS) generation. Mechanistic studies and molecular docking simulations indicated that NC-CV prevents toll-like receptor 4 signaling activation, suppressing nuclear factor κB and mitogen-activated protein kinase pathways. Moreover, the antioxidant activity of NC-CV was primarily based on direct intracellular ROS scavenging rather than the induction of endogenous antioxidant enzymes. Collectively, these findings demonstrated that the venom-derived peptide NC-CV disrupts the self-reinforcing cycle involving inflammatory signaling and oxidative stress in airway epithelium, highlighting its promise as a therapeutic candidate for respiratory disease. Full article

Background/Objectives: Methicillin-resistant Staphylococcus aureus (MRSA) poses a significant global health threat due to its increasing resistance to conventional antibiotics. Antimicrobial peptides (AMPs) derived from natural sources represent a promising alternative. Fragments of spider membrane-active toxins can serve as AMPs with anti-MRSA activity. Methods: To demonstrate this, amino acid sequences of approximately 2000 linear spider venom peptides were fragmented into 9–22-residue-long moieties (75,235 in total) and pre-trained neural networks were used to predict their anti-MRSA activity. As many as 15 peptides with high predicted activity were synthesized, and three AMPs with high anti-MRSA and low hemolytic activities were selected. One of these peptides was studied using high-resolution ¹H-, ¹³C-, and ¹⁵N-NMR spectroscopy in an aqueous solution and lyso-palmitoylphosphatidylglycerol (LPPG) micelles. Wide-line ³¹P-NMR was applied to multilamellar phospholipid liposomes composed of phosphatidylcholine (PC) or phosphatidylglycerol (PG). Results: Low hemolytic activity is explained by non-specific interaction with PC whereas high antibacterial activity arises from specific interaction with PG accompanied with the formation of a tight complex between the N-terminal tripeptide fragment and PG headgroup. The structure of a such complex, stabilized by an ionic interaction between the N-terminal NH₃⁺ group and the lipid phosphate, was determined based on peptide–LPPG NOEs. The most favorable ratio between anti-MRSA and hemolytic activities, i.e., selectivity of the peptides, is attained when the tripeptide consists exclusively of phenylalanine and tryptophan residues. Confocal microscopy confirmed that the most selective peptide deteriorates the plasma membrane of S. aureus. Conclusions: This approach may enable the production of highly selective AMPs against Stapylococci, including MRSA. Full article

Spider-derived venoms are a rich source of cystine knot peptides with immense therapeutic potential. Many of these peptides exert unique biological activities through the modulation of ion channels, including of human voltage-gated sodium (Na_V1.1–Na_V1.9) channels. Na_V channel subtypes have diverse functions determined by their tissue and cellular distribution and biophysical properties, and are pathophysiology mediators in various diseases. Therefore, Na_Vs are central in studies of human biology. This work investigated the pharmacological properties of venom of the Thai theraphosid Ornithoctonus aureotibialis on Na_V channels. We discovered a predominant venom peptide named Oa1a and assessed its pharmacological properties across human Na_V channel subtypes. Synthetic forms of the peptide Oa1a showed preferential inhibition of Na_V1.1 and Na_V1.7, while recombinant Oa1a displayed a preference for inhibiting Na_V1.2, Na_V1.6, and Na_V1.7. Interestingly, all versions of Oa1a peptides exerted dual pharmacological effect by reducing the peak current and slowing fast inactivation of Na_V1.3, consistent with Oa1a having more than one binding site on Na_V channels. Such complex pharmacology was previously observed for a venom peptide in a Central American and Costa Rican tarantula, suggesting a conserved mechanism of action amongst these geographically distinct species. However, Oa1a lacked activity in the T-type channels observed in the tarantula peptide from Central America. Structure–function relationships investigated using molecular modelling showed that the dual pharmacology is driven by a conserved mechanism utilizing a mix of aromatic and charged residues, while the T-type activity appears to require additional charged residues in loop 2 and fewer positive charges in loop 4. Future structure–activity relationship studies of Oa1a will guide the development of pharmacological tools as well as next-generation drugs to treat Na_V channel dysfunction associated with neurological disorders. Full article

The development of effective anticoagulants remains a critical need in modern medicine, particularly for preventing and treating thromboembolic disorders, such as arterial thrombosis and deep vein thrombosis (DVT), as well as complications like ischemic stroke. This study identifies a cysteine-knotted peptide GC38 (sequence: GCSGKGARCAPSKCCSGLSCGRHGGNMYKSCEWNWKTG) derived from the venom gland transcriptome of the Macrothele sp. spider, which exerts thrombus-inhibitory effects by potentiating activated protein C (APC) activity. In vitro assays reveal that GC38 enhances APC activity, prolongs plasma clotting time, and shows no significant cytotoxicity or hemolytic activity. Mechanistically, GC38 interacts allosterically with APC; biolayer interferometry (BLI) confirms this direct interaction, with a dissociation constant K_D of 6.16 μM. Additionally, three in vivo thrombosis models (FeCl₃-induced arterial occlusion, stasis-induced DVT, and cortical photothrombotic stroke) consistently demonstrated that GC38 was effective in alleviating thrombus formation, with tail-bleeding assays confirming its low hemorrhagic risk. Collectively, our findings position GC38 as a pioneering spider venom-derived lead molecule that addresses dual arterial and venous antithrombotic actions. This opens new avenues for developing spider venom-derived peptides as therapeutic agents targeting intravascular coagulation in arteries and veins. Full article

Spiders of the Sicarius genera (Araneae: Sicariidae) are commonly known as six-eyed sand spiders. Of the species described in Latin America, the species S. thomisoides has previously been shown to possess venom with a toxic potential comparable to that observed in the venom of the spider L. laeta. Although identifying the phospholipase D activity in the venom of S. thomisoides, it is still unknown what other components are part of the venom. In this study, we described the identification of the main protein components of S. thomisoides venom, revealing that the phospholipase D family were the majority toxins, followed by Astacin-like metalloproteinases and serine proteases. Additionally, the presence of CRISP-type allergens and peptides from the U-PHTX-Pmx family was identified for the first time in venoms from Sicarius genera. Identifying the components of the Sicarius spider venom is an essential step to understanding its toxicological potential. Full article

Background/Objectives: Bioactive peptides derived from animal venoms, toxins, and secretions demonstrate considerable pharmacological potential for use in the management of diabetes mellitus—a highly prevalent metabolic disorder of substantial global health significance. This integrative review systematically evaluated the current evidence regarding the pharmacological mechanisms underlying the antidiabetic properties of these bioactive peptides. Methods: This study was guided by the research question “What are the mechanisms of action of peptides derived from animal venoms in modulating parameters associated with diabetes?” developed using the PECo framework. A comprehensive literature search was executed across Scopus, PubMed, and Web of Science, focusing on studies from the last five years. Out of 190 identified articles, 17 satisfied the inclusion criteria. Results: Twenty-eight distinct peptides were characterized, exhibiting structural diversity with 7–115 amino acid residues and molecular weights of 900–13,000 Da. These compounds were sourced from venomous taxa including sea anemones, marine snails, spiders, centipedes, scorpions, and snakes. Their antidiabetic mechanisms encompassed glucagon-like peptide-1 (GLP-1) receptor agonism, insulin receptor activation, potassium channel inhibition, glucose transporter type 4 (GLUT4) upregulation, and α-amylase inhibition. Sequence analyses revealed substantial homology among peptides with analogous mechanisms—notably Con-Ins and ILP-Ap04, plus SpTx1 and SsTx-4—suggesting that structural determinants underlie their functional characteristics. Toxicological evaluations of nine peptides demonstrated low-toxicity profiles despite originating from toxic venom, crucial for therapeutic development. Conclusions: These peptides exhibited exceptional pharmacological potency with effective doses in nanogram-to-nanomole per kilogram ranges. Collectively, our findings underscore the therapeutic potential of venom-derived peptides as innovative candidates for use in diabetes management. Full article

The emergence of antimicrobial resistance is a significant challenge in global healthcare, necessitating innovative techniques to address multidrug-resistant pathogens. Multidrug-resistant pathogens like Klebsiella pneumoniae, Acinetobacter baumannii, and Pseudomonas aeruginosa pose significant public health threats, as they are increasingly resistant to common antibiotics, leading to more severe and difficult-to-treat infections. These pathogens are part of the ESKAPE group, which includes Enterococcus faecium, Staphylococcus aureus, and Enterobacter species. Animal venoms, derived from a wide range of species such as snakes, scorpions, spiders, bees, wasps, and ants, represent a rich source of bioactive peptides. Venoms have been a valuable source for drug discovery, providing unique compounds with therapeutic potential. Venom-derived drugs are known for their increased bioactivity, specificity, and stability compared to synthetic alternatives. These compounds are being investigated for various conditions, including treatments for diabetes, pain relief, cancer, and infections, showcasing their remarkable antimicrobial efficacy. In this review, we provide a comprehensive investigation into the potential of venom-derived compounds for developing new antimicrobial agents, including antibacterial, antifungal, antiviral, and antiparasitic therapeutics. Key venom components, including melittin from bee venom, phospholipase A₂ from snake venom, and chlorotoxin from scorpion venom, exhibit potent antimicrobial effects through mechanisms such as membrane disruption, enzymatic inhibition, and immune modulation. We also explore the challenges related to the development and clinical use of venom-derived antimicrobials, including toxicity, stability, and delivery mechanisms. These compounds hold immense promise as transformative tools against resistant pathogens, offering a unique avenue for groundbreaking advancements in antimicrobial research and therapeutic development. Full article

Background: Carbapenem-resistant Klebsiella pneumoniae (CRKP) is a multidrug-resistant (MDR) gram-negative bacterium frequently involved in hospital-acquired pneumonia. The infection caused by this superbug has spread quickly in health centers worldwide, leading to high mortality rates. Due to this emerging scenario, the World Health Organization has categorized CRKP as the highest-priority species for the development of new compounds. In this context, antimicrobial peptides (AMPs) stand out as prototypes for alternative antimicrobials against superbugs, including CRKP. Objectives: We aimed to describe the antibacterial effect of an AMP (LyeTx I), derived from the venom of the spider Lycosa erythrognatha, against CRKP in vitro and in a murine pneumonia model. Results: LyeTx I showed antibacterial effects against all the CRKP clinical isolates tested, with a minimum inhibitory concentration (MIC) range of 2–8 µM and a minimum bactericidal concentration (MBC) range of 2–16 µM. The microbial anionic membrane was the primary target of LyeTx I, which acts by displacing divalent cations bound to this structure in a manner similar to that of polymyxins. Notably, LyeTx I displayed significant lytic activity against mimetic membranes, indicating its potential to disrupt bacterial cell integrity. In in vivo assays, the LyeTx I peptide proved to be safe at a dose of 10 mg/kg. In addition, intraperitoneal use of LyeTx I reduced the bacterial load and inflammation in the lungs of animals infected with a hypervirulent strain of CRKP. Conclusions: These results indicate that LyeTx I is a potential prototype for the development of new antibacterials against MDR species, such as CRKP. Full article

Background/Objectives: This study investigates the structural and biophysical properties of the wild-type antimicrobial peptide LyeTx I, isolated from the venom of the spider Lycosa erythrognatha, and its analog LyeTx I-b, designed to enhance antibacterial activity, selectivity, and membrane interactions by the acetylation and increased amphipathicty. Methods: To understand the mechanisms behind these enhanced properties, comparative analyses of the structural, topological, biophysical, and thermodynamic aspects of the interactions between each peptide and phospholipid bilayers were evaluated. Both peptides were isotopically labeled with ²H₃-Ala and ¹⁵N-Leu to facilitate structural studies via NMR spectroscopy. Results: Circular dichroism and solid-state NMR analyses revealed that, while both peptides adopt α-helical conformations in membrane mimetic environments, LyeTx I-b exhibits a more amphipathic and extended helical structure, which correlates with its enhanced membrane interaction. The thermodynamic properties of the peptide–membrane interactions were quantitatively evaluated in the presence of phospholipid bilayers using ITC and DSC, highlighting a greater propensity of LyeTx I-b to disrupt lipid vesicles. Calcein release studies reveal that both peptides cause vesicle disruption, although DLS measurements and TEM imaging indicate distinct effects on phospholipid vesicle organization. While LyeTx I-b permeabilizes anionic membrane retaining the vesicle integrity, LyeTx I promotes significant vesicle agglutination. Furthermore, DSC and calcein release assays indicate that LyeTx I-b exhibits significantly lower cytotoxicity toward eukaryotic membranes compared to LyeTx I, suggesting greater selectivity for bacterial membranes. Conclusions: Our findings provide insights into the structural and functional modifications that enhance the antimicrobial and therapeutic potential of LyeTx I-b, offering valuable guidance for the design of novel peptides targeting resistant bacterial infections and cancer. Full article