Search Results (100)

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

The discovery of novel cytotoxic drugs is of paramount importance in contemporary medical research, particularly in the search for treatments with fewer side effects and higher specificity. Antimicrobial peptides are an interesting class of molecules for this endeavor. In this context, the LyeTx III, a new peptide extracted from the venom of the Lycosa erythrognatha spider, stands out. The peptide exhibits typical antimicrobial traits: a positive net charge and amphipathic α -helix structure in lipid-like environments. Its unique sequence (GKAMKAIAKFLGR-NH₂), identified via mass spectrometry and Edman degradation, shows limited similarity to existing peptides. Significantly, when liposome-encapsulated, LyeTx III demonstrates selective activity against tumor cells in culture. Our MTT results showed that the cytotoxicity of the peptide increased against HN13 cells when administered as liposomes, with their viability in HN13 cells alone being 98%, compared to 38% in liposome-encapsulated form. This finding underscores that the LyeTx III peptide may be a good candidate for the development of new drugs against cancer. Its activity when encapsulated is promising, as it can increase its half-life in the body and can also be targeted to specific tumors. Full article

The venoms of Theraphosidae spiders have evolved into diverse natural pharmacopeias through selective pressures. Cryptococcus neoformans is a global health threat that frequently causes life-threatening meningitis and fungemia, particularly in immunocompromised patients. In this study, we identify a novel anti-C. neoformans peptide, QS18 (QCFKVCFRKRCFTKCSRS), from the venom gland of China’s native spider species Chilobrachys liboensis by utilizing bioinformatic tools. QS18 shares over 50% sequence similarity with tachyplesin peptides, previously identified only in horseshoe crab hemocytes, expanding the known repertoire of the tachyplesin family to terrestrial arachnids. The oxidative folding of QS18 notably enhances its antifungal activity and stability, resulting in a minimum inhibitory concentration of 1.4 µM. The antimicrobial mechanism of QS18 involves cell membrane disruption. QS18 exhibits less than 5% hemolysis in human erythrocytes, indicating microbial selectivity and a favorable safety profile for therapeutic use. Furthermore, mouse model studies highlight QS18’s ability as an antifungal agent with notable anti-inflammatory activity. Our study demonstrates QS18 as both a promising template for spider venom peptide research and a novel candidate for the development of peptide antifungals. Full article

Background: The emergence and prevalence of antibiotic-resistant bacteria (ARBs) have become a serious global threat, as the morbidity and mortality associated with ARB infections are continuously rising. The activation of quorum sensing (QS) genes can promote biofilm formation, which contributes to the acquisition of drug resistance and increases virulence. Therefore, there is an urgent need to develop new antimicrobial agents to control ARB and prevent further development. Antimicrobial peptides (AMPs) are naturally occurring defense molecules in organisms known to suppress pathogens through a broad range of antimicrobial mechanisms. Methods: In this study, we utilized a previously developed deep-learning model to identify AMP candidates from the venom gland transcriptome of the spider Pardosa astrigera, followed by experimental validation. Results: PA-Win2 was among the top-scoring predicted peptides and was selected based on physiochemical features. Subsequent experimental validation demonstrated that PA-Win2 inhibits the growth of Bacillus subtilis, Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and multidrug-resistant P. aeruginosa (MRPA) strain CCARM 2095. The peptide exhibited strong bactericidal activity against P. aeruginosa, and MRPA CCARM 2095 through the depolarization of bacterial cytoplasmic membranes and alteration of gene expression associated with bacterial survival. In addition, PA-Win2 effectively inhibited biofilm formation and degraded pre-formed biofilms of P. aeruginosa. The gene expression study showed that the peptide treatment led to the downregulation of QS genes in the Las, Pqs, and Rhl systems. Conclusions: These findings suggest PA-Win2 as a promising drug candidate against ARB and demonstrate the potential of in silico methods in discovering functional peptides from biological data. Full article

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. Full article

Animal venom has been gaining traction as a potential source of therapeutics for various diseases. Spiders encompass a wide variety of venom-producing species, of which tarantulas of the family Theraphosidae are widely known across the globe. Research towards tarantula venom therapeutics has led to its potential application as antinociceptives. Death receptors are cellular receptors that induce apoptosis—the body’s natural suicide mechanism—to destroy malfunctioning cells. These are particularly of interest in cancer research, as this mechanism is tampered with, resulting in cancer cell proliferation. In this study, the viability of venom toxins from the Theraphosidae family of spiders to induce apoptosis by binding to human death receptors is investigated by carrying out anti-cancer screening, molecular docking, ADMET evaluation, then molecular dynamics and thermodynamic analysis twice, first to ascertain the best receptor–peptide systems per receptor, and secondly to more comprehensively describe binding stability and thermodynamics. Results point to favorable receptor–peptide interactions due to similarities in equilibrium behavior with the death ligand–death receptor systems, along with favorable end-state binding energies and ADMET analysis results. Further inquiry is recommended to assess the real-life efficacy and viability of theraphotoxins as apoptosis therapeutics and further improve on their ability to induce apoptosis. Full article

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. Full article

Venom plays a crucial role in the defense and predation of venomous animals. Spiders (Araneae) are among the most successful predators and have a fascinating venom composition. Their venom mainly contains disulfide-rich peptides and large proteins. Here, we analyzed spider venom protein families, utilizing transcriptomic and genomic data, and highlighted their similarities and differences. We show that spiders have specific combinations of toxins for better predation and defense, typically comprising a core toxin expressed alongside several auxiliary toxins. Among them, the CAP superfamily is widely distributed and highly expressed in web-building Araneoidea spiders. Our analysis of evolutionary relationships revealed four subfamilies (subA-subD) of the CAP superfamily that differ in structure and potential functions. CAP proteins are composed of a conserved CAP domain and diverse C-terminal domains. CAP subC shares similar domains with the snake ion channel regulator svCRISP proteins, while CAP subD possesses a sequence similar to that of insect venom allergen 5 (Ag5). Furthermore, we show that gene duplication and selective expression lead to increased expression of CAP subD, making it a core member of the CAP superfamily. This study sheds light on the functional diversity of CAP subfamilies and their evolutionary history, which has important implications for fully understanding the composition of spider venom proteins and the core toxin components of web-building spiders. Full article

Polyamines (PAs) are polycationic biogenic amines ubiquitously present in all life forms and are involved in molecular signaling and interaction, determining cell fate (e.g., cell proliferation, dif-ferentiation, and apoptosis). The intricate balance in the PAs’ levels in the tissues will determine whether beneficial or detrimental effects will affect homeostasis. It’s crucial to note that endoge-nous polyamines, like spermine and spermidine, play a pivotal role in our understanding of neu-rological disorders as they interact with membrane receptors and ion channels, modulating neuro-transmission. In spiders and wasps, monoamines (histamine, dopamine, serotonin, tryptamine) and polyamines (spermine, spermidine, acyl polyamines) comprise, with peptides and other sub-stances, the low molecular weight fraction of the venom. Acylpolyamines are venom components exclusively from spiders and a species of solitary wasp, which cause inhibition chiefly of iono-tropic glutamate receptors (AMPA, NMDA, and KA iGluRs) and nicotinic acetylcholine receptors (nAChRs). The first venom acylpolyamines ever discovered (argiopines, Joro and Nephila toxins, and philanthotoxins) have provided templates for the design and synthesis of numerous analogs. Thus far, analogs with high potency exert their effect at nanomolar concentrations, with high se-lectivity toward their ionotropic and ligand receptors. These potent and selective acylpolyamine analogs can serve biomedical purposes and pest control management. The structural modification of acylpolyamine with photolabile and fluorescent groups converted these venom toxins into use-ful molecular probes to discriminate iGluRs and nAchRs in cell populations. In various cases, the linear polyamines, like spermine and spermidine, constituting venom acyl polyamine backbones, have served as cargoes to deliver active molecules via a polyamine uptake system on diseased cells for targeted therapy. In this review, we examined examples of biogenic amines that play an essential role in neural homeostasis and cell signaling, contributing to human health and disease outcomes, which can be present in the venom of arachnids and hymenopterans. With an empha-sis on the spider and wasp venom acylpolyamines, we focused on the origin, structure, derivatiza-tion, and biomedical and biotechnological application of these pharmacologically attractive, chemically modular venom components. Full article

The urgent global health challenge posed by methicillin-resistant Staphylococcus aureus (MRSA) infections demands effective solutions. Antimicrobial peptides (AMPs) represent promising tools of research of new antibacterial agents and LyeTx I mn∆K, a short synthetic peptide based on the Lycosa erythrognatha spider venom, is a good representative. This study focused on analyzing the antimicrobial activities of LyeTx I mn∆K, including minimum inhibitory and bactericidal concentrations, synergy and resensitization assays, lysis activity, the effect on biofilm, and the bacterial death curve in MRSA. Additionally, its characterization was conducted through isothermal titration calorimetry, dynamic light scattering, calcein release, and finally, efficacy in a mice wound model. The peptide demonstrates remarkable efficacy against planktonic cells (MIC 8–16 µM) and biofilms (>30% of inhibition) of MRSA, and outperforms vancomycin in terms of rapid bactericidal action and anti-biofilm effects. The mechanism involves significant membrane damage. Interactions with bacterial model membranes, including those with lysylphosphatidylglycerol (LysylPOPG) modifications, highlight the versatility and selectivity of this compound. Also, the peptide has the ability to sensitize resistant bacteria to conventional antibiotics, showing potential for combinatory therapy. Furthermore, using an in vivo model, this study showed that a formulated gel containing the peptide proved superior to vancomycin in treating MRSA-induced wounds in mice. Together, the results highlight LyeTx I mnΔK as a promising prototype for the development of effective therapeutic strategies against superficial MRSA infections. Full article

Spiders (Araneae), having thrived for over 300 million years, exhibit remarkable diversity, with 47,000 described species and an estimated 150,000 species in existence. Evolving with intricate venom, spiders are nature’s skilled predators. While only a small fraction of spiders pose a threat to humans, their venoms contain complex compounds, holding promise as drug leads. Spider venoms primarily serve to immobilize prey, achieved through neurotoxins targeting ion channels. Peptides constitute a major part of these venoms, displaying diverse pharmacological activities, and making them appealing for drug development. Moreover, spider-venom peptides have emerged as valuable tools for exploring human disease mechanisms. This review focuses on the roles of spider-venom peptides in spider survival strategies and their dual significance as pharmaceutical research tools. By integrating recent discoveries, it provides a comprehensive overview of these peptides, their targets, bioactivities, and their relevance in spider survival and medical research. Full article

With the increasing challenge of controlling infectious diseases due to the emergence of antibiotic-resistant strains, the importance of discovering new antimicrobial agents is rapidly increasing. Animal venoms contain a variety of functional peptides, making them a promising platform for pharmaceutical development. In this study, a novel toxin peptide with antibacterial and anti-inflammatory activities was discovered from the spider venom gland transcriptome by implementing computational approaches. Lycotoxin-Pa2a (Lytx-Pa2a) showed homology to known-spider toxin, where functional prediction indicated the potential of both antibacterial and anti-inflammatory peptides without hemolytic activity. The colony-forming assay and minimum inhibitory concentration test showed that Lytx-Pa2a exhibited comparable or stronger antibacterial activity against pathogenic strains than melittin. Following mechanistic studies revealed that Lytx-Pa2a disrupts both cytoplasmic and outer membranes of bacteria while simultaneously inducing the accumulation of reactive oxygen species. The peptide exerted no significant toxicity when treated to human primary cells, murine macrophages, and bovine red blood cells. Moreover, Lytx-Pa2a alleviated lipopolysaccharide-induced inflammation in mouse macrophages by suppressing the expression of inflammatory mediators. These findings not only suggested that Lytx-Pa2a with dual activity can be utilized as a new antimicrobial agent for infectious diseases but also demonstrated the implementation of in silico methods for discovering a novel functional peptide, which may enhance the future utilization of biological resources. Full article

The escalating prevalence of antibiotic-resistant bacteria poses an immediate and grave threat to public health. Antimicrobial peptides (AMPs) have gained significant attention as a promising alternative to conventional antibiotics. Animal venom comprises a diverse array of bioactive compounds, which can be a rich source for identifying new functional peptides. In this study, we identified a toxin peptide, Lycotoxin-Pa1a (Lytx-Pa1a), from the transcriptome of the Pardosa astrigera spider venom gland. To enhance its functional properties, we employed an in silico approach to design a novel hybrid peptide, KFH-Pa1a, by predicting antibacterial and cytotoxic functionalities and incorporating the amino-terminal Cu(II)- and Ni(II) (ATCUN)-binding motif. KFH-Pa1a demonstrated markedly superior antimicrobial efficacy against pathogens, including multidrug-resistant (MDR) Pseudomonas aeruginosa, compared to Lytx-Pa1a. Notably, KFH-Pa1a exerted several distinct mechanisms, including the disruption of the bacterial cytoplasmic membrane, the generation of intracellular ROS, and the cleavage and inhibition of bacterial DNA. Additionally, the hybrid peptide showed synergistic activity when combined with conventional antibiotics. Our research not only identified a novel toxin peptide from spider venom but demonstrated in silico-based design of hybrid AMP with strong antimicrobial activity that can contribute to combating MDR pathogens, broadening the utilization of biological resources by incorporating computational approaches. Full article