Protonectin (1–6): A novel chemotactic peptide from the venom of the social wasp Agelaia pallipes pallipes

Antimicrobial Peptide Synergies for Fighting Infectious Diseases

Antimicrobial peptides (AMPs) are essential elements of thehost defense system. Characterized by heterogenous structures and broad-spectrumaction, they are promising candidates for combating multidrug resistance. Thecombined use of AMPs with other antimicrobial agents provides a new arsenal ofdrugs with synergistic action, thereby overcoming the drawback of monotherapiesduring infections. AMPs kill microbes via pore formation, thus inhibitingintracellular functions. This mechanism of action by AMPs is an advantage overantibiotics as it hinders the development of drug resistance. The synergisticeffect of AMPs will allow the repurposing of conventional antimicrobials andenhance their clinical outcomes, reduce toxicity, and, most significantly,prevent the development of resistance. In this review, various synergies ofAMPs with antimicrobials and miscellaneous agents are discussed. The effect ofstructural diversity and chemical modification on AMP properties is firstaddressed and then different combinations that can lead to synergistic action,whether this combination is between AMPs and antimicrobials, or AMPs andmiscellaneous compounds, are attended. This review can serve as guidance whenredesigning and repurposing the use of AMPs in combination with other antimicrobialagents for enhanced clinical outcomes.

Exploring the therapeutic potential of an antinociceptive and anti-inflammatory peptide from wasp venom

Animal venoms are rich sources of neuroactive compounds, including anti-inflammatory, antiepileptic, and antinociceptive molecules. Our study identified a protonectin peptide from the wasp Parachartergus fraternus' venom using mass spectrometry and cDNA library construction. Using this peptide as a template, we designed a new peptide, protonectin-F, which exhibited higher antinociceptive activity and less motor impairment compared to protonectin. In drug interaction experiments with naloxone and AM251, Protonectin-F's activity was decreased by opioid and cannabinoid antagonism, two critical antinociception pathways. Further experiments revealed that this effect is most likely not induced by direct action on receptors but by activation of the descending pain control pathway. We noted that protonectin-F induced less tolerance in mice after repeated administration than morphine. Protonectin-F was also able to decrease TNF-α production in vitro and modulate the inflammatory response, which can further contribute to its antinociceptive activity. These findings suggest that protonectin-F may be a potential molecule for developing drugs to treat pain disorders with fewer adverse effects. Our results reinforce the biotechnological importance of animal venom for developing new molecules of clinical interest.

Venom peptides - A comprehensive translational perspective in pain management

Venom peptides have been evolving complex therapeutic interventions that potently and selectively modulate a range of targets such as ion channels, receptors, and signaling pathways of physiological processes making it potential therapeutic. Several venom peptides were deduced in vivo for clinical development targeting pain management, diabetes, cardiovascular diseases, antimicrobial activity. Several contributions have been detailed for a clear perspective for a better understanding of venomous animals, their venom, and their pharmacological effects. Here we unravel and summarize the recent advances in wide venom peptides across varieties of species for their therapeutics prospects.

Protonectin peptides target lipids, act at the interface and selectively kill metastatic breast cancer cells while preserving morphological integrity

Despite the need for innovative compounds as antimicrobial and anticancer agents, natural sources of peptides remain underexplored. Protonectin (PTN), a cationic dodecapeptide of pharmacological interest, presents large hydrophobicity that is associated with the tendency to aggregate and supposedly influences bioactivity. A disaggregating role was assigned to PTN' N-terminal fragment (PTN_1-6), which enhances the bioactivity of PTN in a 1:1 mixture (PTN/PTN_1-6). Spectroscopic techniques and model membranes (phospholipid bilayers and SDS micelles) revealed that environment-dependent aggregation is reduced for PTN/PTN_1-6, but cytotoxicity of PTNs on MDA-MB-231 breast cancer showed the same CC₅₀ values around 16 µM and on MCF-10A epithelial breast cells 6 to 5-fold higher values, revealing a selective interaction. Since PTN_1-6 lacks activity on breast cells, its presence should differently affect PTN activity, suggesting that aggregation could modulate activity depending on the membrane characteristics. Indeed, increased partitioning and lytic activity of PTN/PTN_1-6 were found in model membranes independently of charge density, but affected by the curvature tendency. PTN and PTN/PTN_1-6 do not alter morphology and roughness of cancer cells, indicating a superficial interaction with membranes and consistent with results obtained in NMR experiments. Our results indicate that aggregation of PTNs depends on the membrane characteristics and modulates the activity of the peptides.

Wasp Venom Biochemical Components and Their Potential in Biological Applications and Nanotechnological Interventions

Wasps, members of the order Hymenoptera, are distributed in different parts of the world, including Brazil, Thailand, Japan, Korea, and Argentina. The lifestyles of the wasps are solitary and social. Social wasps use venom as a defensive measure to protect their colonies, whereas solitary wasps use their venom to capture prey. Chemically, wasp venom possesses a wide variety of enzymes, proteins, peptides, volatile compounds, and bioactive constituents, which include phospholipase A2, antigen 5, mastoparan, and decoralin. The bioactive constituents have anticancer, antimicrobial, and anti-inflammatory effects. However, the limited quantities of wasp venom and the scarcity of advanced strategies for the synthesis of wasp venom’s bioactive compounds remain a challenge facing the effective usage of wasp venom. Solid-phase peptide synthesis is currently used to prepare wasp venom peptides and their analogs such as mastoparan, anoplin, decoralin, polybia-CP, and polydim-I. The goal of the current review is to highlight the medicinal value of the wasp venom compounds, as well as limitations and possibilities. Wasp venom could be a potential and novel natural source to develop innovative pharmaceuticals and new agents for drug discovery.

Bradykinin-Potentiating Activity of a Gamma-Irradiated Bioactive Fraction Isolated from Scorpion (Leiurus quinquestriatus) Venom in Rats with Doxorubicin-Induced Acute Cardiotoxicity: Favorable Modulation of Oxidative Stress and Inflammatory, Fibrogenic and Apoptotic Pathways

Although doxorubicin (Dox) is a backbone of chemotherapy, the search for an effective and safe therapy to revoke Dox-induced acute cardiotoxicity remains a critical matter in cardiology and oncology. The current study was the first to explore the probable protective effects of native and gamma-irradiated fractions with bradykinin-potentiating activity (BPA) isolated from scorpion (Leiurus quinquestriatus) venom against Dox-induced acute cardiotoxicity in rats. Native or irradiated fractions (1 μg/g) were administered intraperitoneally (i.p.) twice per week for 3 weeks, and Dox (15 mg/kg, i.p.) was administered on day 21 at 1 h after the last native or irradiated fraction treatment. Electrocardiographic (ECG) aberrations were ameliorated in the Dox-treated rats pretreated with the native fraction, and the irradiated fraction provided greater amelioration of ECG changes than that of the native fraction. The group pretreated with native protein with BPA also exhibited significant improvements in the levels of oxidative stress-related, inflammatory, angiogenic, fibrogenic, and apoptotic markers compared with those of the Dox group. Notably, the irradiated fraction restored these biomarkers to their normal levels. Additionally, the irradiated fraction ameliorated Dox-induced histological changes and alleviated the severity of cardiac injury to a greater extent than that of the native fraction. In conclusion, the gamma-irradiated detoxified fraction of scorpion venom elicited a better cardioprotective effect than that of the native fraction against Dox-induced acute cardiotoxicity in rats.

Revisiting Polybia paulista wasp venom using shotgun proteomics - Insights into the N-linked glycosylated venom proteins

The partial proteome of Polybia paulista wasp venom was previously reported elsewhere using a gel-dependent approach and resulted in the identification of a limited number of venom toxins. Here, we reinvestigated the P. paulista venom using a gel-free shotgun proteomic approach; the highly dynamic range of this approach facilitated the detection and identification of 1673 proteins, of which 23 venom proteins presented N-linked glycosylation as a posttranslational modification. Three different molecular forms of PLA1 were identified as allergenic proteins, and two of these forms were modified by N-linked glycosylation. This study reveals an extensive repertoire of hitherto undescribed proteins that were classified into the following six different functional groups: (i) typical venom proteins; (ii) proteins related to the folding/conformation and PTMs of toxins; (iii) proteins that protect toxins from oxidative stress; (iv) proteins involved in chemical communication; (v) housekeeping proteins; and (vi) uncharacterized proteins. It was possible to identify venom toxin-like proteins that are commonly reported in other animal venoms, including arthropods such as spiders and scorpions. Thus, the findings reported here may contribute to improving our understanding of the composition of P. paulista venom, its envenoming mechanism and the pathologies experienced by the victim after the wasp stinging accident. BIOLOGICAL SIGNIFICANCE: The present study significantly expanded the number of proteins identified in P. paulista venom, contributing to improvements in our understanding of the envenoming mechanism produced by sting accidents caused by this wasp. For example, novel wasp venom neurotoxins have been identified, but no studies have assessed the presence of this type of toxin in social wasp venoms. In addition, 23 N-linked glycosylated venom proteins were identified in the P. paulista venom proteome, and some of these proteins might be relevant allergens that are immunoreactive to human IgE.

Wasp venomic: Unravelling the toxins arsenal of Polybia paulista venom and its potential pharmaceutical applications

Polybia paulista (Hymenoptera: Vespidae) is a neotropical social wasp from southeast Brazil. As most social Hymenoptera, venom from P. paulista comprises a complex mixture of bioactive toxins ranging from low molecular weight compounds to peptides and proteins. Several efforts have been made to elucidate the molecular composition of the P. paulista venom. Data derived from proteomic, peptidomic and allergomic analyses has enhanced our understanding of the whole envenoming process caused by the insect sting. The combined use of bioinformatics, -omics- and molecular biology tools have allowed the identification, characterization, in vitro synthesis and recombinant expression of several wasp venom toxins. Some of these P. paulista - derived bioactive compounds have been evaluated for the rational design of antivenoms and the improvement of allergy specific diagnosis and immunotherapy. Molecular characterization of crude venom extract has enabled the description and isolation of novel toxins with potential biotechnological applications. Here, we review the different approaches that have been used to unravel the venom composition of P. paulista. We also describe the main groups of P. paulista - venom toxins currently identified and analyze their potential in the development of component-resolved diagnosis of allergy, and in the rational design of antivenoms and novel bioactive drugs.

Insects, arachnids and centipedes venom: A powerful weapon against bacteria. A literature review

Currently, new antimicrobial molecules extracted or obtained by natural sources, could be a valide alternative to traditional antibiotics. Most of these molecules are represented by antimicrobial peptides (AMPs), which are essential compounds of insect, arachnids and centipedes venom. AMPs, due to their strong effectiveness, low resistance rates and peculiar mode of action, seem to have all the suitable features to be a powerful weapon against several bacteria, especially considering the increasing antibiotic-resistance phenomena. The present literature review focuses on the antibacterial activity of bee, wasp, ant, scorpion, spider and scolopendra crude venom and of their main biological active compounds. After a brief overview of each animal and venom use in folkloristic medicine, this review reports, in a comprehensive table, the results obtained by the most relevant and recent researches carried out on the antibacterial activity of different venom and their AMPs. For each considered study, the table summarizes data concerning minimal inhibitory concentration values, minimal bactericidal concentration values, the methods employed, scientific name and common names and provenience of animal species from which the crude venom and its respective compounds were obtained.

Differential Properties of Venom Peptides and Proteins in Solitary vs. Social Hunting Wasps

The primary functions of venoms from solitary and social wasps are different. Whereas most solitary wasps sting their prey to paralyze and preserve it, without killing, as the provisions for their progeny, social wasps usually sting to defend their colonies from vertebrate predators. Such distinctive venom properties of solitary and social wasps suggest that the main venom components are likely to be different depending on the wasps' sociality. The present paper reviews venom components and properties of the Aculeata hunting wasps, with a particular emphasis on the comparative aspects of venom compositions and properties between solitary and social wasps. Common components in both solitary and social wasp venoms include hyaluronidase, phospholipase A2, metalloendopeptidase, etc. Although it has been expected that more diverse bioactive components with the functions of prey inactivation and physiology manipulation are present in solitary wasps, available studies on venom compositions of solitary wasps are simply too scarce to generalize this notion. Nevertheless, some neurotoxic peptides (e.g., pompilidotoxin and dendrotoxin-like peptide) and proteins (e.g., insulin-like peptide binding protein) appear to be specific to solitary wasp venom. In contrast, several proteins, such as venom allergen 5 protein, venom acid phosphatase, and various phospholipases, appear to be relatively more specific to social wasp venom. Finally, putative functions of main venom components and their application are also discussed.

Peptidome profiling of venom from the social wasp Polybia paulista

Most crude venom from Polybia paulista is composed of short, linear peptides; however, only five of these peptides are structurally and functionally characterized. Therefore, the peptides in this venom were profiled using an HPLC-IT-TOF/MS and MS(n) system. The presence of type -d and -w ions that are generated from the fragmentation of the side chains was used to resolve I/L ambiguity. The distinction between K and Q residues was achieved through esterification of the α- and ε-amino groups in the peptide chains, followed by mass spectrometry analysis. Fourteen major peptides were detected in P. paulista venom and sequenced; all the peptides were synthesized on solid-phase and submitted to a series of bioassays. Five of them had been previously characterized, and nine were novel toxins. The novel peptides correspond to two wasp kinins, two chemotactic components, three mastoparans, and two peptides of unknown function. The seven novel peptides with identified functions appear to act synergistically with the previously known ones, constituting three well-known families of peptide toxins (wasp kinins, chemotactic peptides, and mastoparans) in the venom of social wasps. These multifunctional toxins can cause pain, oedema formation, haemolysis, chemotaxis of PMNLs, and mast cell degranulation in victims who are stung by wasps.

Echinometrin: a novel mast cell degranulating peptide from the coelomic liquid of Echinometra lucunter sea urchin

Echinometra lucunter is an abundant sea urchin found in Brazilian waters. Accidents caused by this animal are common and are characterized by the penetration of the spines in the skin, which raises an inflammatory reaction through mechanical trauma as well as by the presumable action of toxins. Additionally, there have been reports of inflammatory reaction after the consumption of raw sea urchin eggs. In this work, we have isolated a peptide from E. lucunter coelomic fluid that could elicit inflammatory reactions, such as paw edema, leukocyte recruitment and diminishment of the pain threshold. This peptide was termed Echinometrin. Moreover, the peptide administration was able to produce in vivo degranulation of mouse mast cells, in a dose-response manner. The peptide was 'de novo' sequenced by mass spectrometry and its synthetic analog could reproduce all the observed effects. Sequence alignment indicates that this peptide is comprised in vitellogenin, an abundant nutrient protein present in the gametogenic cells of sea urchins, making it possible that echinometrin would be a cryptide with pro-inflammatory effects.

Chemometric analysis of Hymenoptera toxins and defensins: A model for predicting the biological activity of novel peptides from venoms and hemolymph

When searching for prospective novel peptides, it is difficult to determine the biological activity of a peptide based only on its sequence. The "trial and error" approach is generally laborious, expensive and time consuming due to the large number of different experimental setups required to cover a reasonable number of biological assays. To simulate a virtual model for Hymenoptera insects, 166 peptides were selected from the venoms and hemolymphs of wasps, bees and ants and applied to a mathematical model of multivariate analysis, with nine different chemometric components: GRAVY, aliphaticity index, number of disulfide bonds, total residues, net charge, pI value, Boman index, percentage of alpha helix, and flexibility prediction. Principal component analysis (PCA) with non-linear iterative projections by alternating least-squares (NIPALS) algorithm was performed, without including any information about the biological activity of the peptides. This analysis permitted the grouping of peptides in a way that strongly correlated to the biological function of the peptides. Six different groupings were observed, which seemed to correspond to the following groups: chemotactic peptides, mastoparans, tachykinins, kinins, antibiotic peptides, and a group of long peptides with one or two disulfide bonds and with biological activities that are not yet clearly defined. The partial overlap between the mastoparans group and the chemotactic peptides, tachykinins, kinins and antibiotic peptides in the PCA score plot may be used to explain the frequent reports in the literature about the multifunctionality of some of these peptides. The mathematical model used in the present investigation can be used to predict the biological activities of novel peptides in this system, and it may also be easily applied to other biological systems.