RESUMEN
Novel antibiotics are urgently needed to combat the antibiotic-resistance crisis. We present a machine-learning-based approach to predict antimicrobial peptides (AMPs) within the global microbiome and leverage a vast dataset of 63,410 metagenomes and 87,920 prokaryotic genomes from environmental and host-associated habitats to create the AMPSphere, a comprehensive catalog comprising 863,498 non-redundant peptides, few of which match existing databases. AMPSphere provides insights into the evolutionary origins of peptides, including by duplication or gene truncation of longer sequences, and we observed that AMP production varies by habitat. To validate our predictions, we synthesized and tested 100 AMPs against clinically relevant drug-resistant pathogens and human gut commensals both in vitro and in vivo. A total of 79 peptides were active, with 63 targeting pathogens. These active AMPs exhibited antibacterial activity by disrupting bacterial membranes. In conclusion, our approach identified nearly one million prokaryotic AMP sequences, an open-access resource for antibiotic discovery.
Asunto(s)
Péptidos Antimicrobianos , Aprendizaje Automático , Microbiota , Péptidos Antimicrobianos/farmacología , Péptidos Antimicrobianos/química , Péptidos Antimicrobianos/genética , Humanos , Animales , Antibacterianos/farmacología , Ratones , Metagenoma , Bacterias/efectos de los fármacos , Bacterias/genética , Microbioma Gastrointestinal/efectos de los fármacosRESUMEN
Bioactive peptide therapeutics has been a long-standing research topic. Notably, the antimicrobial peptides (AMPs) have been extensively studied for its therapeutic potential. Meanwhile, the demand for annotating other therapeutic peptides, such as antiviral peptides (AVPs) and anticancer peptides (ACPs), also witnessed an increase in recent years. However, we conceive that the structure of peptide chains and the intrinsic information between the amino acids is not fully investigated among the existing protocols. Therefore, we develop a new graph deep learning model, namely TP-LMMSG, which offers lightweight and easy-to-deploy advantages while improving the annotation performance in a generalizable manner. The results indicate that our model can accurately predict the properties of different peptides. The model surpasses the other state-of-the-art models on AMP, AVP and ACP prediction across multiple experimental validated datasets. Moreover, TP-LMMSG also addresses the challenges of time-consuming pre-processing in graph neural network frameworks. With its flexibility in integrating heterogeneous peptide features, our model can provide substantial impacts on the screening and discovery of therapeutic peptides. The source code is available at https://github.com/NanjunChen37/TP_LMMSG.
Asunto(s)
Aminoácidos , Redes Neurales de la Computación , Péptidos , Aminoácidos/química , Péptidos/química , Biología Computacional/métodos , Aprendizaje Profundo , Péptidos Antimicrobianos/química , AlgoritmosRESUMEN
MOTIVATION: The emergence of drug-resistant pathogens represents a formidable challenge to global health. Using computational methods to identify the antibacterial peptides (ABPs), an alternative antimicrobial agent, has demonstrated advantages in further drug design studies. Most of the current approaches, however, rely on handcrafted features and underutilize structural information, which may affect prediction performance. RESULTS: To present an ultra-accurate model for ABP identification, we propose a novel deep learning approach, PGAT-ABPp. PGAT-ABPp leverages structures predicted by AlphaFold2 and a pretrained protein language model, ProtT5-XL-U50 (ProtT5), to construct graphs. Then the graph attention network (GAT) is adopted to learn global discriminative features from the graphs. PGAT-ABPp outperforms the other fourteen state-of-the-art models in terms of accuracy, F1-score and Matthews Correlation Coefficient on the independent test dataset. The results show that ProtT5 has significant advantages in the identification of ABPs and the introduction of spatial information further improves the prediction performance of the model. The interpretability analysis of key residues in known active ABPs further underscores the superiority of PGAT-ABPp. AVAILABILITY AND IMPLEMENTATION: The datasets and source codes for the PGAT-ABPp model are available at https://github.com/moonseter/PGAT-ABPp/.
Asunto(s)
Biología Computacional , Biología Computacional/métodos , Péptidos Antimicrobianos/química , Péptidos Antimicrobianos/farmacología , Antibacterianos/farmacología , Antibacterianos/química , Aprendizaje ProfundoRESUMEN
Herein, a multifunctional nanohybrid (PL@HPFTM nanoparticles) was fabricated to perform the integration of chemodynamic therapy, photothermal therapy, and biological therapy over the long term at a designed location for continuous antibacterial applications. The PL@HPFTM nanoparticles consisted of a polydopamine/hemoglobin/Fe2+ nanocomplex with comodification of tetrazole/alkene groups on the surface as well as coloading of antimicrobial peptides and luminol in the core. During therapy, the PL@HPFTM nanoparticles would selectively cross-link to surrounding bacteria via tetrazole/alkene cycloaddition under chemiluminescence produced by the reaction between luminol and overexpressed H2O2 at the infected area. The resulting PL@HPFTM network not only significantly damaged bacteria by Fe2+-catalyzed ROS production, effective photothermal conversion, and sustained release of antimicrobial peptides but dramatically enhanced the retention time of these therapeutic agents for prolonged antibacterial therapy. Both in vitro and in vivo results have shown that our PL@HPFTM nanoparticles have much higher bactericidal efficiency and remarkably longer periods of validity than free antibacterial nanoparticles.
Asunto(s)
Antibacterianos , Nanopartículas , Antibacterianos/farmacología , Antibacterianos/química , Animales , Nanopartículas/química , Ratones , Escherichia coli/efectos de los fármacos , Polímeros/química , Indoles/química , Indoles/farmacología , Terapia Fototérmica , Humanos , Staphylococcus aureus/efectos de los fármacos , Péptidos Antimicrobianos/química , Péptidos Antimicrobianos/farmacología , Peróxido de Hidrógeno/química , Peróxido de Hidrógeno/farmacologíaRESUMEN
Short-length antimicrobial peptides (AMPs) have been demonstrated to have intensified antimicrobial activities against a wide spectrum of microbes. Therefore, exploration of novel and promising short AMPs is highly essential in developing various types of antimicrobial drugs or treatments. In addition to experimental approaches, computational methods have been developed to improve screening efficiency. Although existing computational methods have achieved satisfactory performance, there is still much room for model improvement. In this study, we proposed iAMP-DL, an efficient hybrid deep learning architecture, for predicting short AMPs. The model was constructed using two well-known deep learning architectures: the long short-term memory architecture and convolutional neural networks. To fairly assess the performance of the model, we compared our model with existing state-of-the-art methods using the same independent test set. Our comparative analysis shows that iAMP-DL outperformed other methods. Furthermore, to assess the robustness and stability of our model, the experiments were repeated 10 times to observe the variation in prediction efficiency. The results demonstrate that iAMP-DL is an effective, robust, and stable framework for detecting promising short AMPs. Another comparative study of different negative data sampling methods also confirms the effectiveness of our method and demonstrates that it can also be used to develop a robust model for predicting AMPs in general. The proposed framework was also deployed as an online web server with a user-friendly interface to support the research community in identifying short AMPs.
Asunto(s)
Péptidos Antimicrobianos , Aprendizaje Profundo , Péptidos Antimicrobianos/química , Péptidos Antimicrobianos/farmacología , Redes Neurales de la Computación , Biología Computacional/métodos , Péptidos Catiónicos Antimicrobianos/química , Péptidos Catiónicos Antimicrobianos/farmacologíaRESUMEN
Interactions between SJGAP (skipjack tuna GAPDH-related antimicrobial peptide) and four analogs thereof with model bacterial membranes were studied using Fourier-transform infrared spectroscopy (FTIR) and molecular dynamics (MD) simulations. MD trajectory analyses showed that the N-terminal segment of the peptide analogs has many contacts with the polar heads of membrane phospholipids, while the central α helix interacts strongly with the hydrophobic core of the membranes. The peptides also had a marked influence on the wave numbers associated with the phase transition of phospholipids organized as liposomes in both the interface and aliphatic chain regions of the infrared spectra, supporting the interactions observed in the MD trajectories. In addition, interesting links were found between peptide interactions with the aliphatic chains of membrane phospholipids, as determined by FTIR and from the MD trajectories, and the membrane permeabilization capacity of these peptide analogs, as previously demonstrated. To summarize, the combined experimental and computational efforts have provided insights into crucial aspects of the interactions between the investigated peptides and bacterial membranes. This work thus makes an original contribution to our understanding of the molecular interactions underlying the antimicrobial activity of these GAPDH-related antimicrobial peptides from Scombridae.
Asunto(s)
Péptidos Antimicrobianos , Membrana Celular , Proteínas de Peces , Animales , Secuencia de Aminoácidos , Péptidos Antimicrobianos/química , Péptidos Antimicrobianos/farmacología , Péptidos Antimicrobianos/metabolismo , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Proteínas de Peces/química , Proteínas de Peces/metabolismo , Proteínas de Peces/farmacología , Gliceraldehído-3-Fosfato Deshidrogenasas/metabolismo , Gliceraldehído-3-Fosfato Deshidrogenasas/química , Simulación de Dinámica Molecular , Espectroscopía Infrarroja por Transformada de FourierRESUMEN
Antimicrobial peptides (AMPs) are compounds with a variety of bioactive properties. Especially promising are their antibacterial activities, often toward drug-resistant pathogens. Across different AMP sources, AMPs expressed within plants are relatively underexplored with a limited number of plant AMP families identified. Recently, we identified the novel AMPs CC-AMP1 and CC-AMP2 in ghost pepper plants (Capsicum chinense x frutescens), exerting promising antibacterial activity and not classifying into any known plant AMP family. Herein, AMPs related to CC-AMP1 and CC-AMP2 were identified within both Capsicum annuum and Capsicum baccatum. In silico predictions throughout plants were utilized to illustrate that CC-AMP1-like and CC-AMP2-like peptides belong to two broader AMP families, with three-dimensional structural predictions indicating that CC-AMP1-like peptides comprise a novel subfamily of α-hairpinins. The antibacterial activities of several closely related CC-AMP1-like peptides were compared with a truncated version of CC-AMP1 possessing significantly more activity than the full peptide. This truncated peptide was further characterized to possess broad-spectrum antibacterial activity against clinically relevant ESKAPE pathogens. These findings illustrate the value in continued study of plant AMPs toward characterization of novel AMP families, with CC-AMP1-like peptides possessing promising bioactivity.
Asunto(s)
Secuencia de Aminoácidos , Capsicum , Capsicum/química , Capsicum/genética , Antibacterianos/farmacología , Antibacterianos/química , Proteínas de Plantas/química , Proteínas de Plantas/genética , Péptidos Antimicrobianos/química , Péptidos Antimicrobianos/farmacología , Péptidos Antimicrobianos/genética , Datos de Secuencia Molecular , Pruebas de Sensibilidad Microbiana , Péptidos Catiónicos Antimicrobianos/química , Péptidos Catiónicos Antimicrobianos/farmacología , Péptidos Catiónicos Antimicrobianos/genética , Modelos MolecularesRESUMEN
The formation of phase separated membrane domains is believed to be essential for the function of the cell. The precise composition and physical properties of lipid bilayer domains play crucial roles in regulating protein activity and governing cellular processes. Perturbation of the domain structure in human cells can be related to neurodegenerative diseases and cancer. Lipid rafts are also believed to be essential in bacteria, potentially serving as targets for antibiotics. An important question is how the membrane domain structure is affected by bioactive and therapeutic molecules, such as surface-active peptides, which target cellular membranes. Here we focus on antimicrobial peptides (AMPs), crucial components of the innate immune system, to gain insights into their interaction with model lipid membranes containing domains. Using small-angle neutron/X-ray scattering (SANS/SAXS), we show that the addition of several natural AMPs (indolicidin, LL-37, magainin II, and aurein 2.2) causes substantial growth and restructuring of the domains, which corresponds to increased line tension. Contrast variation SANS and SAXS results demonstrate that the peptide inserts evenly in both phases, and the increased line tension can be related to preferential and concentration dependent thinning of the unsaturated membrane phase. We speculate that the lateral restructuring caused by the AMPs may have important consequences in affecting physiological functions of real cells. This work thus shines important light onto the complex interactions and lateral (re)organization in lipid membranes, which is relevant for a molecular understanding of diseases and the action of antibiotics.
Asunto(s)
Microdominios de Membrana , Dispersión del Ángulo Pequeño , Microdominios de Membrana/química , Microdominios de Membrana/metabolismo , Membrana Dobles de Lípidos/química , Membrana Dobles de Lípidos/metabolismo , Péptidos Catiónicos Antimicrobianos/química , Péptidos Catiónicos Antimicrobianos/farmacología , Péptidos Antimicrobianos/química , Péptidos Antimicrobianos/farmacología , Humanos , Difracción de Rayos XRESUMEN
Covering: 1993 to the end of 2022As the rapid development of antibiotic resistance shrinks the number of clinically available antibiotics, there is an urgent need for novel options to fill the existing antibiotic pipeline. In recent years, antimicrobial peptides have attracted increased interest due to their impressive broad-spectrum antimicrobial activity and low probability of antibiotic resistance. However, macromolecular antimicrobial peptides of plant and animal origin face obstacles in antibiotic development because of their extremely short elimination half-life and poor chemical stability. Herein, we focus on medium-sized antibacterial peptides (MAPs) of microbial origin with molecular weights below 2000 Da. The low molecular weight is not sufficient to form complex protein conformations and is also associated to a better chemical stability and easier modifications. Microbially-produced peptides are often composed of a variety of non-protein amino acids and terminal modifications, which contribute to improving the elimination half-life of compounds. Therefore, MAPs have great potential for drug discovery and are likely to become key players in the development of next-generation antibiotics. In this review, we provide a detailed exploration of the modes of action demonstrated by 45 MAPs and offer a concise summary of the structure-activity relationships observed in these MAPs.
Asunto(s)
Antibacterianos , Péptidos Antimicrobianos , Antibacterianos/farmacología , Antibacterianos/química , Péptidos Antimicrobianos/farmacología , Péptidos Antimicrobianos/química , Relación Estructura-Actividad , Desarrollo de MedicamentosRESUMEN
The emergence of clinically drug-resistant malaria parasites requires the urgent development of new drugs. Mosquitoes are vectors of multiple pathogens and have developed resistance mechanisms against them, which often involve antimicrobial peptides (AMPs). An-cecB is an AMP of the malaria-transmitting mosquito genus Anopheles, and we herein report its antimalarial activity against Plasmodium falciparum 3D7, the artemisinin-resistant strain 803, and the chloroquine-resistant strain Dd2 in vitro. We also demonstrate its anti-parasite activity in vivo, using the rodent malaria parasite Plasmodium berghei (ANKA). We show that An-cecB displays potent antimalarial activity and that its mechanism of action may occur through direct killing of the parasite or through interaction with infected red blood cell membranes. Unfortunately, An-cecB was found to be cytotoxic to mammalian cells and had poor antimalarial activity in vivo. However, its truncated peptide An-cecB-1 retained most of its antimalarial activity and avoided its cytotoxicity in vitro. An-cecB-1 also showed better antimalarial activity in vivo. Mosquito-derived AMPs may provide new ideas for the development of antimalarial drugs against drug-resistant parasites, and An-cecB has potential use as a template for antimalarial peptides.
Asunto(s)
Anopheles , Antimaláricos , Plasmodium berghei , Plasmodium falciparum , Animales , Antimaláricos/farmacología , Anopheles/efectos de los fármacos , Anopheles/parasitología , Plasmodium falciparum/efectos de los fármacos , Plasmodium berghei/efectos de los fármacos , Ratones , Cecropinas/farmacología , Péptidos Antimicrobianos/farmacología , Péptidos Antimicrobianos/química , Malaria/tratamiento farmacológico , Malaria/parasitología , Eritrocitos/efectos de los fármacos , Eritrocitos/parasitología , Humanos , Mosquitos Vectores/efectos de los fármacos , Mosquitos Vectores/parasitología , Femenino , Proteínas de Insectos/farmacología , Resistencia a Medicamentos/efectos de los fármacos , Cloroquina/farmacología , Pruebas de Sensibilidad ParasitariaRESUMEN
Innate immunity of invertebrates offers potent antimicrobial peptides (AMPs) against drug-resistant infections. To identify new worm ß-hairpin AMPs, we explored the sequence diversity of proteins with a BRICHOS domain, which comprises worm AMP precursors. Strikingly, we discovered new BRICHOS AMPs not in worms, but in caecilians, the least studied clade of vertebrates. Two precursor proteins from Microcaecilia unicolor and Rhinatrema bivittatum resemble SP-C lung surfactants and bear worm AMP-like peptides at C-termini. The analysis of M. unicolor tissue transcriptomes shows that the AMP precursor is highly expressed in the lung along with regular SP-C, suggesting a different, protective function. The peptides form right-twisted ß-hairpins, change conformation upon lipid binding, and rapidly disrupt bacterial membranes. Both peptides exhibit broad-spectrum activity against multidrug-resistant ESKAPE pathogens with 1-4 µM MICs and remarkably low toxicity, giving 40-70-fold selectivity towards bacteria. These BRICHOS AMPs, previously unseen in vertebrates, reveal a novel lung innate immunity mechanism and offer a promising antibiotics template.
Asunto(s)
Péptidos Antimicrobianos , Pulmón , Animales , Secuencia de Aminoácidos , Anfibios/inmunología , Anfibios/metabolismo , Péptidos Catiónicos Antimicrobianos/química , Péptidos Catiónicos Antimicrobianos/metabolismo , Péptidos Antimicrobianos/química , Péptidos Antimicrobianos/metabolismo , Inmunidad Innata , Pulmón/inmunología , Pulmón/metabolismo , Pruebas de Sensibilidad MicrobianaRESUMEN
Photocatalytic nanoparticles offer antimicrobial effects under illumination due to the formation of reactive oxygen species (ROS), capable of degrading bacterial membranes. ROS may, however, also degrade human cell membranes and trigger toxicity. Since antimicrobial peptides (AMPs) may display excellent selectivity between human cells and bacteria, these may offer opportunities to effectively "target" nanoparticles to bacterial membranes for increased selectivity. Investigating this, photocatalytic TiO2 nanoparticles (NPs) are coated with the AMP LL-37, and ROS generation is found by C11-BODIPY to be essentially unaffected after AMP coating. Furthermore, peptide-coated TiO2 NPs retain their positive ζ-potential also after 1-2 h of UV illumination, showing peptide degradation to be sufficiently limited to allow peptide-mediated targeting. In line with this, quartz crystal microbalance measurements show peptide coating to promote membrane binding of TiO2 NPs, particularly so for bacteria-like anionic and cholesterol-void membranes. As a result, membrane degradation during illumination is strongly promoted for such membranes, but not so for mammalian-like membranes. The mechanisms of these effects are elucidated by neutron reflectometry. Analogously, LL-37 coating promoted membrane rupture by TiO2 NPs for Gram-negative and Gram-positive bacteria, but not for human monocytes. These findings demonstrate that AMP coating may selectively boost the antimicrobial effects of photocatalytic NPs.
Asunto(s)
Membrana Celular , Nanopartículas , Titanio , Titanio/química , Titanio/farmacología , Humanos , Catálisis , Nanopartículas/química , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Antiinfecciosos/farmacología , Antiinfecciosos/química , Péptidos Antimicrobianos/química , Péptidos Antimicrobianos/farmacología , Péptidos/química , Péptidos/farmacología , Tecnicas de Microbalanza del Cristal de CuarzoRESUMEN
Antimicrobial peptides (AMPs) are of growing interest as potential candidates that may offer more resilience against antimicrobial resistance than traditional antibiotic agents. In this article, we perform the first inâ silico study of the synthetic ß sheet-forming AMP GL13K. Through atomistic simulations of single and multi-peptide systems under different conditions, we are able to shine a light on the short timescales of early aggregation. We find that isolated peptide conformations are primarily dictated by sequence rather than charge, whereas changing charge has a significant impact on the conformational free energy landscape of multi-peptide systems. We demonstrate that the loss of charge-charge repulsion is a sufficient minimal model for experimentally observed aggregation. Overall, our work explores the molecular biophysical underpinnings of the first stages of aggregation of a unique AMP, laying necessary groundwork for its further development as an antibiotic candidate.
Asunto(s)
Péptidos Antimicrobianos , Péptidos Antimicrobianos/química , Péptidos Antimicrobianos/farmacología , Péptidos Antimicrobianos/síntesis química , Conformación Proteica en Lámina beta , Simulación de Dinámica Molecular , Péptidos Catiónicos Antimicrobianos/química , Péptidos Catiónicos Antimicrobianos/farmacología , Agregado de Proteínas/efectos de los fármacos , Antibacterianos/farmacología , Antibacterianos/química , Antibacterianos/síntesis química , Termodinámica , Secuencia de AminoácidosRESUMEN
Endogenous antimicrobial-immunomodulatory molecules (EAIMs) are essential to immune-mediated human health and evolution. Conventionally, antimicrobial peptides (AMPs) have been regarded as the dominant endogenous antimicrobial molecule; however, AMPs are not sufficient to account for the full spectrum of antimicrobial-immunomodulatory duality occurring within the human body. The threat posed by pathogenic microbes is pervasive with the capacity for widespread impact across many organ systems and multiple biochemical pathways; accordingly, the host needs the capacity to react with an equally diverse response. This can be attained by having EAIMs that traverse the full range of molecular size (small to large molecules) and structural diversity (including molecules other than peptides). This review identifies multiple molecules (peptide/protein, lipid, carbohydrate, nucleic acid, small organic molecule, and metallic cation) as EAIMs and discusses the possibility of cooperative, additive effects amongst the various EAIM classes during the host response to a microbial assault. This comprehensive consideration of the full molecular diversity of EAIMs enables the conclusion that EAIMs constitute a previously uncatalogued structurally diverse and collectively underappreciated immuno-active group of integrated molecular responders within the innate immune system's first line of defence.
Asunto(s)
Inmunidad Innata , Inmunidad Innata/efectos de los fármacos , Humanos , Péptidos Antimicrobianos/química , Péptidos Antimicrobianos/farmacología , Péptidos Antimicrobianos/metabolismo , Antiinfecciosos/química , Antiinfecciosos/farmacología , Antiinfecciosos/metabolismo , Ácidos Nucleicos/química , Ácidos Nucleicos/metabolismo , Ácidos Nucleicos/inmunología , Agentes Inmunomoduladores/química , Agentes Inmunomoduladores/farmacología , Animales , Carbohidratos/química , Carbohidratos/inmunologíaRESUMEN
OBJECTIVES: Pseudomonas aeruginosa and Acinetobacter baumannii are ranked as top-priority organisms by WHO. Antimicrobial peptides (AMPs) are promising antimicrobial agents that are highly effective against serious bacterial infections. METHODS: In our previous study, a series of α-helical AMPs were screened using a novel multiple-descriptor strategy. The current research suggested that S24 exhibited strong antimicrobial activity against major pathogenic bacteria, and displayed minimal haemolysis, good serum stability and maintained salt resistance. RESULTS: We found that S24 exerted an antimicrobial effect by destroying outer membrane permeability and producing a strong binding effect on bacterial genomic DNA that inhibits genomic DNA migration. Furthermore, S24 exerted a strong ability to promote healing in wound infected by P. aeruginosa, A. baumannii and mixed strains in a mouse model. CONCLUSIONS: Overall, S24 showed good stability under physiological conditions and excellent antimicrobial activity, suggesting it may be a potential candidate for the development of serious bacterial infection treatment.
Asunto(s)
Infecciones por Acinetobacter , Acinetobacter baumannii , Antibacterianos , Pruebas de Sensibilidad Microbiana , Infecciones por Pseudomonas , Pseudomonas aeruginosa , Infección de Heridas , Acinetobacter baumannii/efectos de los fármacos , Pseudomonas aeruginosa/efectos de los fármacos , Animales , Infección de Heridas/tratamiento farmacológico , Infección de Heridas/microbiología , Ratones , Infecciones por Acinetobacter/tratamiento farmacológico , Infecciones por Acinetobacter/microbiología , Infecciones por Pseudomonas/tratamiento farmacológico , Infecciones por Pseudomonas/microbiología , Antibacterianos/farmacología , Péptidos Antimicrobianos/farmacología , Péptidos Antimicrobianos/química , Modelos Animales de Enfermedad , Permeabilidad de la Membrana Celular/efectos de los fármacos , Humanos , ADN Bacteriano/genéticaRESUMEN
Scorpion venoms have proven to be excellent sources of antimicrobial agents. However, although many of them have been functionally characterized, they remain underutilized as pharmacological agents, despite their evident therapeutic potential. In this review, we discuss the physicochemical properties of short scorpion venom antimicrobial peptides (ssAMPs). Being generally short (13-25 aa) and amidated, their proven antimicrobial activity is generally explained by parameters such as their net charge, the hydrophobic moment, or the degree of helicity. However, for a complete understanding of their biological activities, also considering the properties of the target membranes is of great relevance. Here, with an extensive analysis of the physicochemical, structural, and thermodynamic parameters associated with these biomolecules, we propose a theoretical framework for the rational design of new antimicrobial drugs. Through a comparison of these physicochemical properties with the bioactivity of ssAMPs in pathogenic bacteria such as Staphylococcus aureus or Acinetobacter baumannii, it is evident that in addition to the net charge, the hydrophobic moment, electrostatic energy, or intrinsic flexibility are determining parameters to understand their performance. Although the correlation between these parameters is very complex, the consensus of our analysis suggests that there is a delicate balance between them and that modifying one affects the rest. Understanding the contribution of lipid composition to their bioactivities is also underestimated, which suggests that for each peptide, there is a physiological context to consider for the rational design of new drugs.
Asunto(s)
Péptidos Antimicrobianos , Venenos de Escorpión , Venenos de Escorpión/química , Venenos de Escorpión/farmacología , Péptidos Antimicrobianos/química , Péptidos Antimicrobianos/farmacología , Animales , Humanos , Antiinfecciosos/farmacología , Antiinfecciosos/química , Interacciones Hidrofóbicas e Hidrofílicas , Péptidos Catiónicos Antimicrobianos/farmacología , Péptidos Catiónicos Antimicrobianos/química , TermodinámicaRESUMEN
BACKGROUND: The world faces a major infectious disease challenge. Interest in the discovery, design, or development of antimicrobial peptides (AMPs) as an alternative approach for the treatment of bacterial infections has increased. Insects are a good source of AMPs which are the main effector molecules of their innate immune system. Black Soldier Fly Larvae (BSFL) are being developed for large-scale rearing for food sustainability, waste reduction and as sustainable animal and fish feed. Bioinformatic studies have suggested that BSFL have the largest number of AMPs identified in insects. However, most AMPs identified in BSF have not yet undergone antimicrobial evaluation but are promising leads to treat critical infections. RESULTS: Jg7197.t1, Jg7902.t1 and Jg7904.t1 were expressed into the haemolymph of larvae following infection with Salmonella enterica serovar Typhimurium and were predicted to be AMPs using the computational tool ampir. The genes encoding these proteins were within 2 distinct clusters in chromosome 1 of the BSF genome. Following removal of signal peptides, predicted structures of the mature proteins were superimposed, highlighting a high degree of structural conservation. The 3 AMPs share primary sequences with proteins that contain a Kunitz-binding domain; characterised for inhibitory action against proteases, and antimicrobial activities. An in vitro antimicrobial screen indicated that heterologously expressed SUMO-Jg7197.t1 and SUMO-Jg7902.t1 did not show activity against 12 bacterial strains. While recombinant SUMO-Jg7904.t1 had antimicrobial activity against a range of Gram-negative and Gram-positive bacteria, including the serious pathogen Pseudomonas aeruginosa. CONCLUSIONS: We have cloned and purified putative AMPs from BSFL and performed initial in vitro experiments to evaluate their antimicrobial activity. In doing so, we have identified a putative novel defensin-like AMP, Jg7904.t1, encoded in a paralogous gene cluster, with antimicrobial activity against P. aeruginosa.
Asunto(s)
Antibacterianos , Defensinas , Dípteros , Larva , Animales , Defensinas/farmacología , Defensinas/genética , Defensinas/química , Defensinas/aislamiento & purificación , Antibacterianos/farmacología , Antibacterianos/química , Dípteros/genética , Larva/efectos de los fármacos , Larva/genética , Pruebas de Sensibilidad Microbiana , Secuencia de Aminoácidos , Proteínas de Insectos/genética , Proteínas de Insectos/farmacología , Proteínas de Insectos/química , Péptidos Antimicrobianos/farmacología , Péptidos Antimicrobianos/genética , Péptidos Antimicrobianos/química , Salmonella typhimurium/efectos de los fármacos , Salmonella typhimurium/genética , Bacterias Gramnegativas/efectos de los fármacosRESUMEN
Recently, the discovery of antimicrobial peptides (AMPs) as excellent candidates for overcoming antibiotic resistance has attracted significant attention. AMPs are short peptides active against bacteria, cancer cells, and viruses. It has been shown that the SARS-CoV-2 nucleocapsid protein (N-P) undergoes liquid-liquid phase separation in the presence of RNA, resulting in biocondensate formation. These biocondensates are crucial for viral replication as they concentrate the viral RNA with the host cell's protein machinery required for viral protein expression. Thus, N-P biocondensates are promising targets to block or slow down viral RNA transcription and consequently virion assembly. We investigated the ability of three AMPs to interfere with N-P/RNA condensates. Using microscopy techniques, supported by biophysical characterization, we found that the AMP LL-III partitions into the condensate, leading to clustering. Instead, the AMP CrACP1 partitions into the droplets without affecting their morphology but reducing their dynamics. Conversely, GKY20 leads to the formation of fibrillar structures after partitioning. It can be expected that such morphological transformation severely impairs the normal functionality of the N-P droplets and thus virion assembly. These results could pave the way for the development of a new class of AMP-based antiviral agents targeting biocondensates.
Asunto(s)
Péptidos Antimicrobianos , Proteínas de la Nucleocápside de Coronavirus , SARS-CoV-2 , SARS-CoV-2/efectos de los fármacos , SARS-CoV-2/metabolismo , Péptidos Antimicrobianos/química , Péptidos Antimicrobianos/farmacología , Proteínas de la Nucleocápside de Coronavirus/química , Proteínas de la Nucleocápside de Coronavirus/metabolismo , Humanos , ARN Viral/metabolismo , ARN Viral/química , Fosfoproteínas/química , Fosfoproteínas/metabolismo , Antivirales/farmacología , Antivirales/química , Replicación Viral/efectos de los fármacosRESUMEN
Cushioned lipid bilayers are structures consisting of a lipid bilayer supported on a solid substrate with an intervening layer of soft material. They offer possibilities for studying the behavior and interactions of biological membranes more accurately under physiological conditions. In this work, we continue our studies of cushion formation induced by histatin 5 (24Hst5), focusing on the effect of the length of the peptide chain. 24Hst5 is a short, positively charged, intrinsically disordered saliva peptide, and here, both a shorter (14Hst5) and a longer (48Hst5) peptide variant were evaluated. Experimental surface active techniques were combined with coarse-grained Monte Carlo simulations to obtain information about these peptides. Results show that at 10 mM NaCl, both the shorter and the longer peptide variants behave like 24Hst5 and a cushion below the bilayer is formed. At 150 mM NaCl, however, no interaction is observed for 24Hst5. On the contrary, a cushion is formed both in the case of 14Hst5 and 48Hst5, and in the latter, an additional thick, diffuse, and highly hydrated layer of peptide and lipid molecules is formed, on top of the bilayer. Similar trends were observed from the simulations, which allowed us to hypothesize that positively charged patches of the amino acids lysine and arginine in all three peptides are essential for them to interact with and translocate over the bilayer. We therefore hypothesize that electrostatic interactions are important for the interaction between the solid-supported lipid bilayers and the peptide depending on the linear charge density through the primary sequence and the positively charged patches in the sequence. The understanding of how, why, and when the cushion is formed opens up the possibility for this system to be used in the research and development of new drugs and pharmaceuticals.
Asunto(s)
Histatinas , Membrana Dobles de Lípidos , Método de Montecarlo , Membrana Dobles de Lípidos/química , Histatinas/química , Péptidos Antimicrobianos/químicaRESUMEN
Phage-encoded endolysins have emerged as a potential substitute to conventional antibiotics due to their exceptional benefits including host specificity, rapid host killing, least risk of resistance. In addition to their antibacterial potency and biofilm eradication properties, endolysins are reported to exhibit synergism with other antimicrobial agents. In this study, the synergistic potency of endolysins was dissected with antimicrobial peptides to enhance their therapeutic effectiveness. Recombinantly expressed and purified bacteriophage endolysin [T7 endolysin (T7L); and T4 endolysin (T4L)] proteins have been used to evaluate the broad-spectrum antibacterial efficacy using different bacterial strains. Antibacterial/biofilm eradication studies were performed in combination with different antimicrobial peptides (AMPs) such as colistin, nisin, and polymyxin B (PMB) to assess the endolysin's antimicrobial efficacy and their synergy with AMPs. In combination with T7L, polymyxin B and colistin effectively eradicated the biofilm of Pseudomonas aeruginosa and exhibited a synergistic effect. Further, a combination of T4L and nisin displayed a synergistic effect against Staphylococcus aureus biofilms. In summary, the obtained results endorse the theme of combinational therapy consisting of endolysins and AMPs as an effective remedy against the drug-resistant bacterial biofilms that are a serious concern in healthcare settings.