Spider Venom Research Articles

Peptide Toxin Diversity and a Novel Antimicrobial Peptide from the Spider Oxyopes forcipiformis

Spider venoms are emerging as a rich source of bioactive peptide toxins with therapeutic potential. Lynx spiders of the genus Oxyopes are small, cursorial hunters that employ complex venom to subdue arthropod prey. However, extracting crude venom from these diminutive arachnids poses significant challenges. This study presents a transcriptome analysis of venom glands from an undescribed Oxyopes forcipiformis species, revealing 339 putative protein and peptide toxin sequences categorized into seven functional groups. The venom composition was dominated by membrane-active peptides (40.71%), venom auxiliary proteins (22.71%), neurotoxins (15.63%), channel active peptides (7.08%) and uncharacterized components (13.87%). Additionally, phylogenetic analysis of 65 disulfide-bond-rich peptides yielded six distinct families based on sequence homology and cysteine framework. Finally, a novel antimicrobial peptide, GK37, was identified using in silico and homology analyses. Our data suggested that GK37 presented significant antibacterial activity against Gram-positive bacteria Staphylococcus aureus with a minimum inhibitory concentration (MIC) of 1.552 µM by disrupting bacterial membranes. At 4× MICs, GK37 almost showed no hemolytic activity on blood cells or toxicity against Hek293T cells. Our findings provided a basis for targeted studies of the diversity and pharmacological effects of lynx spider peptide. We elucidated a valuable high-throughput approach for obtaining proteins and peptides from small-group spiders.

Mechanism of acid-sensing ion channel modulation by Hi1a.

Acid-sensing ion channels (ASICs) are trimeric cation-selective channels activated by extracellular acidification. Amongst many pathological roles, ASICs are an important mediator of ischemic cell death and hence an attractive drug target for stroke treatment as well as other conditions. A peptide called Hi1a, isolated from Australian funnel web spider venom, inhibits ASIC1a and attenuates cell death in a stroke model up to 8 h after stroke induction. Here, we set out to understand the molecular basis for Hi1a's action. Hi1a is a bivalent toxin with two inhibitory cystine knot domains joined by a short linker. We found that both Hi1a domains modulate human ASIC1a gating with the N-terminal domain impairing channel activation while the C-terminal domain produces a "pro-open" phenotype even at submicromolar concentrations. Interestingly, both domains bind at the same site since a single point mutation, F352A, abolishes functional effects and reduces toxin affinity in surface plasmon resonance measurements. Therefore, the action of Hi1a at ASIC1a appears to arise through a mutually exclusive binding model where either the N or C domain of a single Hi1a binds one ASIC1a subunit. An ASIC1a trimer may bind several inhibitory N domains and one or more pro-open C domains at any one time, accounting for the incomplete inhibition of wild type Hi1a. We also found that the functional differences between these two domains are partially transferred by mutagenesis, affording new insight into the channel function and possible novel avenues of drug design.

The Wheel of Fortune: Helical Wheel Alanine Scanning of a Spider Venom Antimicrobial Peptide Reveals Residues Involved in Antimicrobial and Cytotoxic Activity.

A preference for several amino acids is observed to occur at particular positions of cationic α-helical antimicrobial peptides (AMPs), which ensures the formation of amphipathic regions once they assume their correct secondary structure in membranes or membrane-mimicking environments and makes them active against pathogens. This study determined the effect of alanine mutations on the secondary structure and bioactivity of lyp1987 (GRLQAFLAKMKEIAAQTL-NH2), a cationic α-helical AMP obtained from the venom of Lycosa poonaensis which exhibits broad range activity against Gram-positive and Gram-negative bacteria with micromolar minimum inhibitory concentrations (MIC). CD spectroscopy revealed no significant difference in the secondary structure, with all alanine-substituted analogs exhibiting predominantly α-helical structure in buffered 2,2,2-trifluoroethanol solution. Alanine substitution at Glu12 and Thr17 increased the activity of lyp1987 against Gram-positive and -negative bacteria, while alanine substitution at Lys9 increased its selectivity against Gram-positive bacteria. Further investigation can be done to determine positions and substitutions that will give less cytotoxic analogs.

Structural basis of α-latrotoxin transition to a cation-selective pore

The potent neurotoxic venom of the black widow spider contains a cocktail of seven phylum-specific latrotoxins (LTXs), but only one, α-LTX, targets vertebrates. This 130 kDa toxin binds to receptors at presynaptic nerve terminals and triggers a massive release of neurotransmitters. It is widely accepted that LTXs tetramerize and insert into the presynaptic membrane, thereby forming Ca2+-conductive pores, but the underlying mechanism remains poorly understood. LTXs are homologous and consist of an N-terminal region with three distinct domains, along with a C-terminal domain containing up to 22 consecutive ankyrin repeats. Here we report cryoEM structures of the vertebrate-specific α-LTX tetramer in its prepore and pore state. Our structures, in combination with AlphaFold2-based structural modeling and molecular dynamics simulations, reveal dramatic conformational changes in the N-terminal region of the complex. Four distinct helical bundles rearrange and together form a highly stable, 15 nm long, cation-impermeable coiled-coil stalk. This stalk, in turn, positions an N-terminal pair of helices within the membrane, thereby enabling the assembly of a cation-permeable channel. Taken together, these data give insight into a unique mechanism for membrane insertion and channel formation, characteristic of the LTX family, and provide the necessary framework for advancing novel therapeutics and biotechnological applications.

Using a conditioned place preference assay in fruit flies to examine effects of insecticidal compounds on contextual memory

Insecticides are vital for safeguarding agricultural crops against pests, albeit many lack selectivity towards pest species and are poorly bio-degradable. This leads to targeting of beneficial organisms like pollinators and widespread environmental contamination of soil and water. Exposure to insecticides such as neonicotinoids causes insect paralysis and mortality at higher doses, while sublethal doses can disrupt other functions that are crucial for survival such as learning and memory performance. Potent and selective arachnid venom peptides affecting a variety of molecular targets are being explored as bioinsecticide candidates. However, their effect on insect learning is poorly understood. We therefore established a sucrose-induced conditioned place preference (CPP) assay using Drosophila melanogaster fruit flies to provide a means of evaluating how various classes of insecticidal compounds interact with insect memory to assess their broader ecological consequences. Our results confirmed the adverse effect of a sublethal dose of the neonicotinoid insecticide imidacloprid (20 pg/fly) on fly CPP formation upon daily injection during the conditioning phase. However, imidacloprid did not affect CPP retrieval when applied after the conditioning phase. Sublethal doses of the two insecticidal spider venom peptides μ-DGTX-Dc1a (Dc1a; 70 pg/fly) and U1-AGTX-Ta1a (Ta1a; 125 pg/fly) had no effect on either CPP formation or retrieval, underlining their potential as novel and safe bioinsecticide candidates.

ID: 329655 Stellate Ganglion Blocks to Treat CRPS and Neuropathy Caused by Brown Recluse Spider Bite

ID: 329655 Stellate Ganglion Blocks to Treat CRPS and Neuropathy Caused by Brown Recluse Spider Bite

Enlightening the toxinological dark matter of spider venom enzymes

Spiders produce highly adapted venoms featuring a complex mixture of biomolecules used mainly for hunting and defense. The most prominent components are peptidic neurotoxins, a major focus of research and drug development, whereas venom enzymes have been largely neglected. Nevertheless, investigation of venom enzymes not only reveals insights into their biological functions, but also provides templates for future industrial applications. Here we compared spider venom enzymes validated at protein level contained in the VenomZone database and from all publicly available proteo-transcriptomic spider venom datasets. We assigned reported enzymes to cellular processes and known venom functions, including toxicity, prey pre-digestion, venom preservation, venom component activation, and spreading factors. Our study unveiled extensive discrepancy between public databases and publications with regard to enzyme coverage, which impedes the development of novel spider venom enzyme-based applications. Uncovering the previously unrecognized abundance and diversity of venom enzymes will open new avenues for spider venom biodiscovery.

Latrophilin-3 as a downstream effector of the androgen receptor induces bladder cancer progression

Emerging evidence indicates that androgen receptor (AR) signaling plays a critical role in the pathogenesis of male-dominant urothelial cancer and its outgrowth. Meanwhile, latrophilins (LPHNs), a group of the G-protein-coupled receptors to which a spider venom latrotoxin (LTX) is known to bind, remain largely uncharacterized in neoplastic diseases. The present study aimed to determine the functional role of LPHN3 (encoded by the ADGRL3 gene), in association with AR signaling, in the progression of bladder cancer. In AR-positive bladder cancer lines, dihydrotestosterone considerably increased the expression levels of ADGRL3 and LPHN3, while chromatin immunoprecipitation assay revealed the binding of AR to the promoter region of ADGRL3. Treatment with LPHN3 ligands (e.g. α-LTX, FLRT3) resulted in the induction of ADGRL3 expression, as well as cell viability, in bladder cancer lines. By contrast, LPHN3 knockdown via shRNA virus infection significantly reduced the viability and migration of these cells. Immunohistochemistry in transurethral resection specimens further showed a strong correlation between LPHN3 and AR expression. Moreover, LPHN3 positivity in muscle-invasive bladder tumors, as an independent prognosticator, was associated with a significantly higher risk of disease progression and disease-specific mortality following radical cystectomy. These findings suggest that LPHN3 functions as a downstream effector of AR and promotes the growth of bladder cancer.

Optimizing Nav1.7-Targeted Analgesics: Revealing Off-Target Effects of Spider Venom-Derived Peptide Toxins and Engineering Strategies for Improvement.

The inhibition of Nav1.7 is a promising strategy for the development of analgesic treatments. Spider venom-derived peptide toxins are recognized as significant sources of Nav1.7 inhibitors. However, their development has been impeded by limited selectivity. In this study, eight peptide toxins from three distinct spider venom Nav channel families demonstrated robust inhibition of hNav1.7, rKv4.2, and rKv4.3 (rKv4.2/4.3) currents, exhibiting a similar mode of action. The analysis of structure and function relationship revealed a significant overlap in the pharmacophore responsible for inhibiting hNav1.7 and rKv4.2 by HNTX-III, although Lys25 seems to play a more pivotal role in the inhibition of rKv4.2/4.3. Pharmacophore-guided rational design is employed for the development of an mGpTx1 analogue, mGpTx1-SA, which retains its inhibition of hNav1.7 while significantly reducing its inhibition of rKv4.2/4.3 and eliminating cardiotoxicity. Moreover, mGpTx1-SA demonstrates potent analgesic effects in both inflammatory and neuropathic pain models, accompanied by an improved in vivo safety profile. The results suggest that off-target inhibition of rKv4.2/4.3 by specific spider peptide toxins targeting hNav1.7 may arise from a conserved binding motif. This insight promises to facilitate the design of hNav1.7-specific analgesics, aimed at minimizing rKv4.2/4.3 inhibition and associated toxicity, thereby enhancing their suitability for therapeutic applications.

Deadly cures: a drug candidate to treat ischemic injuries the heart and brain from venom of the lethal Australian funnel-web spider

Deadly cures: a drug candidate to treat ischemic injuries the heart and brain from venom of the lethal Australian funnel-web spider

228.1: Improving donor heart preservation with funnel web spider venom and the anti-diabetic drug empagliflozin.

228.1: Improving donor heart preservation with funnel web spider venom and the anti-diabetic drug empagliflozin.

A roadmap to the enzymes from spider venom: biochemical ecology, molecular diversity, and value for the bioeconomy

Spiders are ancient and highly successful predators, which use venom for both predation and defense. Their venoms are complex mixtures of potent biological molecules, emerging as a prolific source of biomolecular innovation in agriculture, biomedicine, and bioeconomy. While small cysteine-rich neurotoxins are typically considered the main components of spider venoms, recent research has shown that spider venoms also contain many high-molecular-weight proteins, especially enzymes. To date, very little is known about the diversity, biochemistry and ecology of these components. Here, we provide the first systematic overview of spider venom enzymes, describing all known examples in terms of their properties and functions in the spider venom system. We argue that the sheer diversity of these neglected spider venom compounds offers significant translational potential and holds great potential for the bioeconomy, reflecting a wide range of technical applications such as industrial production, food processing, and waste management.

Cell Penetrating Peptide Enhances the Aphidicidal Activity of Spider Venom-Derived Neurotoxin.

HxTx-Hv1h, a neurotoxic peptide derived from spider venom, has been developed for use in commercial biopesticide formulations. Cell Penetrating Peptides (CPPs) are short peptides that facilitate the translocation of various biomolecules across cellular membranes. Here, we evaluated the aphidicidal efficacy of a conjugated peptide, HxTx-Hv1h/CPP-1838, created by fusing HxTx-Hv1h with CPP-1838. Additionally, we aimed to establish a robust recombinant expression system for HxTx-Hv1h/CPP-1838. We successfully achieved the secretory production of HxTx-Hv1h, its fusion with Galanthus nivalis agglutinin (GNA) forming HxTx-Hv1h/GNA and HxTx-Hv1h/CPP-1838 in yeast. Purified HxTx-Hv1h exhibited contact toxicity against Megoura crassicauda, with a 48 h median lethal concentration (LC50) of 860.5 μg/mL. Fusion with GNA or CPP-1838 significantly enhanced its aphidicidal potency, reducing the LC50 to 683.5 μg/mL and 465.2 μg/mL, respectively. The aphidicidal efficacy was further improved with the addition of surfactant, decreasing the LC50 of HxTx-Hv1h/CPP-1838 to 66.7 μg/mL-over four times lower compared to HxTx-Hv1h alone. Furthermore, we engineered HxTx-Hv1h/CPP-1838 multi-copy expression vectors utilizing the BglBrick assembly method and achieved high-level recombinant production in laboratory-scale fermentation. This study is the first to document a CPP fusion strategy that enhances the transdermal aphidicidal activity of a natural toxin like HxTx-Hv1h and opens up the possibility of exploring the recombinant production of HxTx-Hv1h/CPP-1838 for potential applications.

Novel insights into the application of recombinant mutated phospholipases D as antigens for developing new strategies against Loxoscelism

Loxoscelism is the pathological condition triggered by a brown spider bite. The venom of these spiders is rich in phospholipases D (PLDs), which can induce virtually all local and systemic manifestations. Recombinant mutated PLDs from clinically relevant Loxosceles species in South America have been investigated as potential antigens to develop novel therapeutic strategies for loxoscelism. However, certain gaps need to be addressed before a clinical approach can be implemented. In this study, we examined the potential of these recombinant mutated PLDs as antigens by testing some variations in the immunization scheme. Furthermore, we evaluated the efficacy of the produced antibodies in neutralizing the nephrotoxicity and sphingomyelinase activity of brown spider venoms. Our findings indicate that the number of immunizations has a greater impact on the effectiveness of neutralization compared to the amount of antigen. Specifically, two or three doses were equally effective in reducing dermonecrosis and edema. Additionally, three immunizations proved to be more effective in neutralizing mice lethality than one or two. Moreover, immunizations mitigated the signs of kidney injury, a crucial aspect given that acute renal failure is a serious systemic complication. In vitro inhibition of the sphingomyelinase activity of Loxosceles venoms, a key factor in vivo toxicity, was nearly complete after incubation with antibodies raised against these antigens. These findings underscore the importance of implementing an effective immunization scheme with multiple immunizations, without the need for high antigen doses, and enhances the spectrum of neutralization exhibited by antibodies generated with these antigens. In summary, these results highlight the strong potential of these antigens for the development of new therapeutic strategies against cutaneous and systemic manifestations of loxoscelism.

Antiepileptic profile of Parawixin-11, purified from Parawixia bistriata spider venom (Araneae, Araneidae), in Wistar rats.

The pharmacological treatment of epilepsy is often complex due to the lack of efficacy in many patients and profound side effects from current drugs, including sedation, motor impairment, and teratogenesis. In the quest for new antiepileptic drugs, animal venoms offer a valuable source of neuroactive molecules targeting ion channels and neurotransmitter receptors. This study investigates the antiepileptic potential of compounds isolated from the venom of the Parawixia bistriata spider. One compound, designated Parawixin-11, demonstrated significant anticonvulsant effects when injected into the cerebral ventricle in a dose-response manner. It effectively countered seizures induced by bicuculline (ED50 0.16µg/animal), pentylenetetrazole (ED50 0.08µg/animal), strychnine (ED50 0.05µg/animal), pilocarpine (ED50 0.10µg/animal), and NMDA (ED50 0.008µg/animal). We also assessed whether intracerebroventricular administration of Parawixin-11 caused motor or cognitive impairments in rats using the open field, rotarod, and Morris water maze tests. No differences in exploration or movement were observed with doses of 0.3, 0.2, or 0.1µg of Parawixin-11. Although there was an increased latency to find the platform during the acquisition phase of the Morris water maze test, no differences in spatial memory retention were noted. Given Parawixin-11's potency against NMDA-induced seizures, we hypothesize that it may modulate the glutamatergic system, aligning with the mechanisms of several spider-derived polyamines.

Latrophilins as Downstream Effectors of Androgen Receptors including a Splice Variant, AR-V7, Induce Prostate Cancer Progression.

Latrophilins (LPHNs), a group of the G-protein-coupled receptor to which a spider venom latrotoxin (LTX) is known to bind, remain largely uncharacterized in neoplastic diseases. In the present study, we aimed to determine the role of LPHNs in the progression of prostate cancer. We assessed the actions of LPHNs, including LPHN1, LPHN2, and LPHN3, in human prostate cancer lines via their ligand (e.g., α-LTX, FLRT3) treatment or shRNA infection, as well as in surgical specimens. In androgen receptor (AR)-positive LNCaP/C4-2/22Rv1 cells, dihydrotestosterone considerably increased the expression levels of LPHNs, while chromatin immunoprecipitation assay revealed the binding of endogenous ARs, including AR-V7, to the promoter region of each LPHN. Treatment with α-LTX or FLRT3 resulted in induction in the cell viability and migration of both AR-positive and AR-negative lines. α-LTX and FLRT3 also enhanced the expression of Bcl-2 and phosphorylated forms of JAK2 and STAT3. Meanwhile, the knockdown of each LPHN showed opposite effects on all of those mediated by ligand treatment. Immunohistochemistry in radical prostatectomy specimens further showed the significantly elevated expression of each LPHN in prostate cancer, compared with adjacent normal-appearing prostate, which was associated with a significantly higher risk of postoperative biochemical recurrence in both univariate and multivariable settings. These findings indicate that LPHNs function as downstream effectors of ARs and promote the growth of androgen-sensitive, castration-resistant, or even AR-negative prostate cancer.

Transcriptomic analyses reveals a diverse venom composition in Agelena limbata (Araneae: Agelenaidae)

Spider venom is a natural source of diverse biomolecules, but due to technical limitations, only a small fraction has been studied. With the advancement of omics technologies, research on spider venom has broadened, greatly promoting systematic studies of spider venom. Agelena limbata is a common spider found in vegetation, known for constructing funnel-shaped webs, and feeding on insects such as Diptera and Homoptera. However, due to its small size and the difficulty in obtaining venom, the composition of Agelena limbata venom has never been studied. In this study, a transcriptomics approach was used to analyze the toxin components in the venom of Agelena limbata, resulting in the identification of 28 novel toxin-like sequences and 24 peptidases. Based on sequence similarity and differences in cysteine motifs, the 28-novel toxin-like sequences were classified into 10 superfamilies. According to the results annotated in the database, the 24 peptidases were divided into six distinct families, with the serine protease family being the most common. A phylogenetic tree was constructed using the toxin-like sequences of Agelena limbata along with Psechrus triangulus and Hippasa lycosina. An analysis of the structural domains and motifs of Agelena limbata was also conducted. The results indicated that Agelena limbata is more distantly related to the other two species of funnel-web spiders, and that the toxin superfamily IX has a unique function compared to the other superfamilies. This study reveals the components of the Agelena limbata venom, deepening our understanding of it, and through bioinformatics analysis, has identified unique functions of the toxin superfamilies, providing a scientific basis for the development of bioactive drugs in the future.

Latrophilin-3 as a downstream effector of the androgen receptor induces urothelial tumorigenesis.

Emerging evidence indicates that androgen receptor (AR) signaling plays a critical role in the pathogenesis of male-dominant urothelial cancer. Meanwhile, latrophilins (LPHNs), a group of the G-protein-coupled receptor to which a spider venom latrotoxin is known to bind, remain largely uncharacterized in neoplastic diseases. The present study aimed to determine the functional role of LPHN3 (encoded by the ADGRL3 gene), in association with AR signaling, in urothelial tumorigenesis. In human normal urothelial SVHUC cells, AR overexpression and androgen treatment considerably increased the expression levels of ADGRL3/LPHN3, while chromatin immunoprecipitation assay revealed the binding of AR to the promoter region of ADGRL3. In SVHUC or SVHUC-AR cells with exposure to a chemical carcinogen 3-methylcholanthrene, LPHN3 activation via ligand (e.g., α-latrotoxin, FLRT3) treatment during the process of the neoplastic/malignant transformation or LPHN3 knockdown via shRNA virus infection induced or reduced, respectively, the oncogenic activity. In N-butyl-N-(4-hydroxybutyl)nitrosamine-treated female mice, α-latrotoxin or FLRT3 injection accelerated the development of bladder tumors. Immunohistochemistry in surgical specimens further showed the significantly elevated expression of LPHN3 in non-muscle-invasive bladder tumors, compared with adjacent normal urothelial tissues, which was associated with a marginally (p = 0.051) higher risk of disease recurrence after transurethral resection. In addition, positivity of LPHN3 and AR in these tumors was strongly correlated. These findings indicate that LPHN3 functions as a downstream effector of AR and promotes urothelial tumorigenesis.

Correction to "A Brief Overview of the Toxic Sphingomyelinase Ds of Brown Recluse Spider Venom and Other Organisms and Simple Methods To Detect Production of Its Signature Cyclic Ceramide Phosphate".

Correction to "A Brief Overview of the Toxic Sphingomyelinase Ds of Brown Recluse Spider Venom and Other Organisms and Simple Methods To Detect Production of Its Signature Cyclic Ceramide Phosphate".

Engineering a wolf spider A-family toxin towards increased antimicrobial activity but low toxicity

Spider-derived peptides with insecticidal, antimicrobial and/or cytolytic activities, also known as spider venom antimicrobial peptides (AMPs), can be found in the venoms of RTA-clade spiders. They show translational potential as therapeutic leads. A set of 52 AMPs has been described in the Chinese wolf spider (Lycosa shansia), and many have been shown to exhibit antibacterial effects. Here we explored the potential to enhance their antimicrobial activity using bioengineering. We generated a panel of artificial derivatives of an A-family peptide and screened their activity against selected microbial pathogens, vertebrate cells and insects. In several cases, we increased the antimicrobial activity of the derivatives while retaining the low cytotoxicity of the parental molecule. Furthermore, we injected the peptides into adult Drosophila suzukii and found no evidence of insecticidal effects, confirming the low levels of toxicity. Our data therefore suggest that spider venom linear peptides naturally defend the venom gland against microbial colonization and can be modified into more potent antimicrobial agents that could help to battle infectious diseases in the future.