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2.
Science ; 368(6490)2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32355003

RESUMO

Antimicrobial peptides (AMPs) are essential components of immune defenses of multicellular organisms and are currently in development as anti-infective drugs. AMPs have been classically assumed to have broad-spectrum activity and simple kinetics, but recent evidence suggests an unexpected degree of specificity and a high capacity for synergies. Deeper evaluation of the molecular evolution and population genetics of AMP genes reveals more evidence for adaptive maintenance of polymorphism in AMP genes than has previously been appreciated, as well as adaptive loss of AMP activity. AMPs exhibit pharmacodynamic properties that reduce the evolution of resistance in target microbes, and AMPs may synergize with one another and with conventional antibiotics. Both of these properties make AMPs attractive for translational applications. However, if AMPs are to be used clinically, it is crucial to understand their natural biology in order to lessen the risk of collateral harm and avoid the crisis of resistance now facing conventional antibiotics.


Assuntos
Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/genética , Peptídeos Catiônicos Antimicrobianos/farmacologia , Farmacorresistência Bacteriana , Evolução Molecular , Animais , Peptídeos Catiônicos Antimicrobianos/química , Proteínas de Drosophila/genética , Proteínas de Drosophila/farmacologia , Sinergismo Farmacológico , Humanos , Polimorfismo Genético , Pesquisa Médica Translacional
4.
PLoS One ; 15(3): e0230021, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32160226

RESUMO

Supplementing chicken feed with antibiotics can improve survival and prevent disease outbreaks. However, overuse of antibiotics may promote the development of antibiotic-resistant bacteria. Recently, antimicrobial peptides have been proposed as alternatives to antibiotics in animal husbandry. Here, we evaluate the effects of antimicrobial peptide, Epinephelus lanceolatus piscidin (EP), in Gallus gallus domesticus. The gene encoding EP was isolated, sequenced, codon-optimized and cloned into a Pichia pastoris recombinant protein expression system. The expressed recombinant EP (rEP) was then used as a dietary supplement for G. g. domesticus; overall health, growth performance and immunity were assessed. Supernatant from rEP-expressing yeast showed in vitro antimicrobial activity against Gram-positive and Gram-negative bacteria, according to an inhibition-zone diameter (mm) assay. Moreover, the antimicrobial peptide function of rEP was temperature independent. The fermentation broth yielded a spray-dried powder formulation containing 262.9 µg EP/g powder, and LC-MS/MS (tandem MS) analysis confirmed that rEP had a molecular weight of 4279 Da, as expected for the 34-amino acid peptide; the DNA sequence of the expression vector was also validated. We then evaluated rEP as a feed additive for G. g. domesticus. Treatment groups included control, basal diet and rEP at different doses (0.75, 1.5, 3.0, 6.0 and 12%). Compared to control, rEP supplementation increased G. g. domesticus weight gain, feed efficiency, IL-10 and IFN-γ production. Our results suggest that crude rEP could provide an alternative to traditional antibiotic feed additives for G. g. domesticus, serving to enhance growth and health of the animals.


Assuntos
Peptídeos Catiônicos Antimicrobianos/metabolismo , Galinhas/imunologia , Sistema Imunitário/metabolismo , Perciformes/metabolismo , Sequência de Aminoácidos , Animais , Anti-Infecciosos/análise , Anti-Infecciosos/metabolismo , Anti-Infecciosos/farmacologia , Peptídeos Catiônicos Antimicrobianos/análise , Peptídeos Catiônicos Antimicrobianos/classificação , Peptídeos Catiônicos Antimicrobianos/genética , Galinhas/crescimento & desenvolvimento , Cromatografia Líquida de Alta Pressão , Clonagem Molecular , Suplementos Nutricionais , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Sistema Imunitário/efeitos dos fármacos , Interferon gama/metabolismo , Interleucina-10/metabolismo , Filogenia , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/farmacologia , Alinhamento de Sequência , Espectrometria de Massas em Tandem , Temperatura
5.
PLoS One ; 15(3): e0228740, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32214347

RESUMO

Parasitic diseases are a neglected and serious problem, especially in underdeveloped countries. Among the major parasitic diseases, Leishmaniasis figures as an urgent challenge due to its high incidence and severity. At the same time, the indiscriminate use of antibiotics by the population is increasing together with resistance to medicines. To address this problem, new antibiotic-like molecules that directly kill or inhibit the growth of microorganisms are necessary, where antimicrobial peptides (AMPs) can be of great help. In this work, the ferrocene molecule, one active compound with low levels of in vivo toxicity, was coupled to the N-terminus of the RP1 peptide (derived from the human chemokine CXCL4), aiming to evaluate how this change modifies the structure, biological activity, and toxicity of the peptide. The peptide and the conjugate were synthesized using the solid phase peptide synthesis (SPPS). Circular dichroism assays in PBS showed that the RP1 peptide and its conjugate had a typical spectrum for disordered structures. The Fc-RP1 presented anti-amastigote activity against Leishmania amazonensis (IC50 = 0.25 µmol L-1). In comparison with amphotericin B, a second-line drug approved for leishmaniasis treatment, (IC50 = 0.63 µmol L-1), Fc-RP1 was more active and showed a 2.5-fold higher selectivity index. The RP1 peptide presented a MIC of 4.3 µmol L-1 against S. agalactiae, whilst Fc-RP1 was four times more active (MIC = 0.96 µmol L-1), indicating that ferrocene improved the antimicrobial activity against Gram-positive bacteria. The Fc-RP1 peptide also decreased the minimum inhibitory concentration (MIC) in the assays against E. faecalis (MIC = 7.9 µmol L-1), E. coli (MIC = 3.9 µmol L-1) and S. aureus (MIC = 3.9 µmol L-1). The cytotoxicity of the compounds was tested against HaCaT cells, and no significant activity at the highest concentration tested (500 µg. mL-1) was observed, showing the high potential of this new compound as a possible new drug. The coupling of ferrocene also increased the vesicle permeabilization of the peptide, showing a direct relation between high peptide concentration and high carboxyfluorescein release, which indicates the action mechanism by pore formation on the vesicles. Several studies have shown that ferrocene destabilizes cell membranes through lipid peroxidation, leading to cell lysis. It is noteworthy that the Fc-RP1 peptide synthesized here is a prototype of a bioconjugation strategy, but it still is a compound with great biological activity against neglected and fish diseases.


Assuntos
Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/farmacologia , Compostos Ferrosos/química , Metalocenos/química , Sequência de Aminoácidos , Animais , Peptídeos Catiônicos Antimicrobianos/metabolismo , Peptídeos Catiônicos Antimicrobianos/toxicidade , Bactérias/efeitos dos fármacos , Leishmania/efeitos dos fármacos , Camundongos , Testes de Sensibilidade Microbiana , Permeabilidade
7.
Subcell Biochem ; 94: 63-80, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32189296

RESUMO

Anti-lipopolysaccharide factors (ALFs) are a type of antimicrobial peptide (AMP) which show broad-spectrum antimicrobial activity against Gram-positive bacteria, Gram-negative bacteria, fungi and viruses. In this chapter, we review the discovery and classification of this kind of antimicrobial peptide in crustaceans. The structure and function, as well as the mechanism of antibacterial and antiviral activities of ALFs will be summarized and discussed. We will then describe the expression and regulation of various ALF genes in different crustacean species. Finally, the application prospects of ALFs in drug development and disease-resistant genetic breeding will be pointed out and discussed. The review will also discuss several key questions such as the systematic classification and expression regulation of the ALF genes, as well as the future application of ALFs and ALF-derived peptides.


Assuntos
Peptídeos Catiônicos Antimicrobianos/farmacologia , Proteínas de Artrópodes/farmacologia , Crustáceos , Animais , Bactérias/efeitos dos fármacos , Crustáceos/genética , Crustáceos/microbiologia , Crustáceos/virologia , Desenvolvimento de Medicamentos , Fungos/efeitos dos fármacos , Lipopolissacarídeos , Vírus/efeitos dos fármacos
8.
Int J Nanomedicine ; 15: 513-519, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32099353

RESUMO

Background: In recent years, numerous bacteria have become resistant to conventional antibiotics. Fortunately, an increasing body of research indicates that through the addition of specific metabolites (like sugars), the antibacterial activity of certain drugs can be enhanced. A new type of self-assembled nano-peptide amphiphile (SANPA) was designed in this study to treat antibiotic-resistant bacterial infections and to reduce the use of antibiotics. Methods: Here, SANPAs were self-assembled into nanorod structures with a diameter of ca. 10.5 nm at concentrations greater than the critical micelle concentration (CMC) of 44.67 µM. Both Gram-positive and Gram-negative bacteria were treated with SANPAs with fructose supplementation. Results: After a 30-min fructose pre-incubation, SANPAs reduced bacteria growth relative to non-fructose treatments at all concentrations. Cytotoxicity assays indicated that the presence of fructose seemed to slightly ameliorate the cytotoxic effect of the treatment on model human fetal osteoblasts (or bone-forming cells) and human dermal fibroblasts. Conclusion: We demonstrated here that SANPAs-like nanomaterials have a promising potential to treat antibiotic-resistant bacteria, especially when added to fructose, potentially limiting their associated infections.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Farmacorresistência Bacteriana/efeitos dos fármacos , Frutose/farmacologia , Peptídeos/química , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/farmacologia , Células Cultivadas , Escherichia coli/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Frutose/química , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Humanos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Nanoestruturas/química , Peptídeos/farmacologia
9.
Chem Commun (Camb) ; 56(19): 2897-2900, 2020 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-32037418

RESUMO

[Tm(DPA)3]3- was used to generate multiple, paramagnetic nuclear Overhauser effect NMR spectra of cationic peptides when weakly bound to a lipopolysaccharide micelle. Increased spectral resolution combined with a marked increase in the number of distance restraints yielded high resolution structures of polymyxin and MSI-594 in the liposaccharide bound state.


Assuntos
Peptídeos Catiônicos Antimicrobianos/química , Elementos da Série dos Lantanídeos/química , Micelas , Ressonância Magnética Nuclear Biomolecular/métodos , Indicadores e Reagentes/química , Peptídeos/química , Polimixina B/química , Conformação Proteica
10.
Crit Care ; 24(1): 47, 2020 02 10.
Artigo em Inglês | MEDLINE | ID: mdl-32041659

RESUMO

OBJECTIVES: The intestinal epithelium compartmentalizes the sterile bloodstream and the commensal bacteria in the gut. Accumulating evidence suggests that this barrier is impaired in sepsis, aggravating systemic inflammation. Previous studies reported that cathelicidin is differentially expressed in various tissues in sepsis. However, its role in sepsis-induced intestinal barrier dysfunction has not been investigated. DESIGN: To examine the role of cathelicidin in polymicrobial sepsis, cathelicidin wild-(Cnlp+/+) and knockout (Cnlp-/-) mice underwent cecal-ligation and puncture (CLP) followed by the assessment of septic mortality and morbidity as well as histological, biochemical, immunological, and transcriptomic analyses in the ileal tissues. We also evaluated the prophylactic and therapeutic efficacies of vitamin D3 (an inducer of endogenous cathelicidin) in the CLP-induced murine polymicrobial sepsis model. RESULTS: The ileal expression of cathelicidin was increased by three-fold after CLP, peaking at 4 h. Knockout of Cnlp significantly increased 7-day mortality and was associated with a higher murine sepsis score. Alcian-blue staining revealed a reduced number of mucin-positive goblet cells, accompanied by reduced mucin expression. Increased number of apoptotic cells and cleavage of caspase-3 were observed. Cnlp deletion increased intestinal permeability to 4kD fluorescein-labeled dextran and reduced the expression of tight junction proteins claudin-1 and occludin. Notably, circulating bacterial DNA load increased more than two-fold. Transcriptome analysis revealed upregulation of cytokine/inflammatory pathway. Depletion of Cnlp induced more M1 macrophages and neutrophils compared with the wild-type mice after CLP. Mice pre-treated with cholecalciferol (an inactive form of vitamin D3) or treated with 1alpha, 25-dihydroxyvitamin D3 (an active form of VD3) had decreased 7-day mortality and significantly less severe symptoms. Intriguingly, the administration of cholecalciferol after CLP led to worsened 7-day mortality and the associated symptoms. CONCLUSIONS: Endogenous cathelicidin promotes intestinal barrier integrity accompanied by modulating the infiltration of neutrophils and macrophages in polymicrobial sepsis. Our data suggested that 1alpha, 25-dihydroxyvitamin D3 but not cholecalciferol is a potential therapeutic agent for treating sepsis.


Assuntos
Peptídeos Catiônicos Antimicrobianos , Mucosa Intestinal , Sepse , Animais , Peptídeos Catiônicos Antimicrobianos/fisiologia , Mucosa Intestinal/metabolismo , Macrófagos , Masculino , Camundongos , Camundongos Knockout , Neutrófilos , Sepse/fisiopatologia , Vitamina D/análogos & derivados , Vitamina D/farmacologia
11.
Cell Host Microbe ; 27(1): 115-128.e8, 2020 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-31917956

RESUMO

Antiviral immunity in insects is mediated by the RNA interference (RNAi) pathway. Viruses evade antiviral RNAi by expressing virulence factors known as viral suppressors of RNAi (VSR). Here, we report the identification of VINR, a Drosophila VSR-interacting long non-coding (lnc) RNA that activates non-canonical innate immune signaling upon detection of the dsRNA-binding VSR of Drosophila C virus (DCV). VINR is required for the induction of antimicrobial peptide (AMP) genes but dispensable for antiviral RNAi. VINR functions by preventing the ubiquitin proteasome-dependent degradation of Cactin, a coiled-coil and arginine-serine-rich domain-containing protein that regulates a non-cannonical antimicrobial pathway for AMP induction. CRISPR-Cas9 knockout of VINR in Drosophila cells enhances DCV replication independently of antiviral RNAi, and VINR-knockout adult flies exhibit enhanced disease susceptibility to DCV and bacteria. Our findings reveal a counter counter-defense strategy activated by a lncRNA in response to the viral suppression of the primary antiviral RNAi immunity.


Assuntos
Proteínas de Transporte/metabolismo , Dicistroviridae/imunologia , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/imunologia , RNA Longo não Codificante , Animais , Peptídeos Catiônicos Antimicrobianos/genética , Peptídeos Catiônicos Antimicrobianos/metabolismo , Sistemas CRISPR-Cas , Dicistroviridae/genética , Dicistroviridae/patogenicidade , Drosophila melanogaster/genética , Técnicas de Silenciamento de Genes , Imunidade Inata , Interferência de RNA/imunologia , RNA Longo não Codificante/genética , RNA Longo não Codificante/imunologia , RNA Longo não Codificante/metabolismo , Transdução de Sinais , Proteínas Virais/metabolismo , Fatores de Virulência/metabolismo
12.
Parasit Vectors ; 13(1): 20, 2020 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-31931867

RESUMO

BACKGROUND: MF6p/host defense molecules (HDMs) are a broad family of small proteins secreted by helminth parasites. Although the physiological role of MF6p/HDMs in trematode parasites is not fully understood, their potential biological function in maintaining heme homeostasis and modulating host immune response has been proposed. METHODS: A gene encoding the MF6p/HDM of Clonorchis sinensis (CsMF6p/HDM) was cloned. Recombinant CsMF6p/HDM (rCsMF6p/HDM) was expressed in Escherichia coli. The biochemical and immunological properties of rCsMF6/HDM were analyzed. CsMF6p/HDM induced pro-inflammatory response in RAW 264.7 cells was analyzed by cytokine array assay, reverse transcription polymerase chain reaction, and enzyme-linked immunosorbent assay. The structural feature of CsMF6p/HDM was analyzed by three-dimensional modeling and molecular docking simulations. RESULTS: The CsMF6p/HDM shares a high level of amino acid sequence similarity with orthologs from other trematodes and is expressed in diverse developmental stages of the parasite. The rCsMF6p/HDM bound to bacteria-derived lipopolysaccharide (LPS), without effectively neutralizing LPS-induced inflammatory response in RAW 264.7 macrophage cells. Rather, the rCsMF6p/HDM induced pro-inflammatory immune response, which is characterized by the expression of TNF-α and IL-6, in RAW 264.7 cells. The rCsMF6p/HDM-induced pro-inflammatory immune response was regulated by JNK and p38 MAPKs, and was effectively down-regulated via inhibition of NF-κB. The structural analysis of CsMF6p/HDM and the docking simulation with LPS suggested insufficient capture of LPS by CsMF6p/HDM, which suggested that rCsMF6p/HDM could not effectively neutralize LPS-induced inflammatory response in RAW 264.7 cells. CONCLUSIONS: Although rCsMF6p/HDM binds to LPS, the binding affinity may not be sufficient to maintain a stable complex of rCsMF6p/HDM and LPS. Moreover, the rCsMF6p/HDM-induced pro-inflammatory response is characterized by the release of IL-6 and TNF-α in RAW 264.7 macrophage cells. The pro-inflammatory response induced by rCsMF6p/HDM is mediated via NF-κB-dependent MAPK signaling pathway. These results collectively suggest that CsMF6p/HDM mediates C. sinensis-induced inflammation cascades that eventually lead to hepatobiliary diseases.


Assuntos
Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/genética , Clonorchis sinensis/metabolismo , Macrófagos/imunologia , Animais , Peptídeos Catiônicos Antimicrobianos/imunologia , Peptídeos Catiônicos Antimicrobianos/metabolismo , Clonagem Molecular , Clonorquíase/etiologia , Citocinas/metabolismo , Doenças do Sistema Digestório/etiologia , Doenças do Sistema Digestório/parasitologia , Escherichia coli , Imunidade Celular , Inflamação/metabolismo , Sistema de Sinalização das MAP Quinases , Macrófagos/parasitologia , Camundongos , Simulação de Acoplamento Molecular/métodos , NF-kappa B/metabolismo , Células RAW 264.7 , Trematódeos , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
13.
Pestic Biochem Physiol ; 163: 102-107, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31973845

RESUMO

Anthracnose is a leaf spot, blossom blight, or fruit rot disease caused by Colletotrichum gloeosporioides (Penz.). It is the most prevalent disease in mango-growing countries worldwide. Lipopeptides, such as those in the iturin family, account for the majority of antifungal secondary metabolites in Bacillus subtilis, Bacillus amyloliquefaciens and Bacillus velezensis, and includes bacillomycin D. Thus far, the mechanism of bacillomycin D's activity has not been clear. In this study, bacillomycin D was isolated from B. velezensis HN-2, which strongly inhibits C. gloeosporioides (Penz.). The median inhibitory concentration of bacillomycin D was 2.162 µg/mL, causing deformation and damage to C. gloeosporioides (Penz.). Bacillomycin D showed more potent activity against C. gloeosporioides (Penz.) than two common fungicides prochloraz and mancozeb. Scanning and transmission electron microscopy revealed that bacillomycin D could injure the cell wall and cell membrane of the hyphae and spores of C. gloeosporioides (Penz.), and the cytoplasm and organelles inside the cell were exuded and formed empty holes. This research clarifies the mechanism underlying bacillomycin D antifungal activity and reveals its high potential as a biopesticide to control phytopathogens.


Assuntos
Bacillus , Colletotrichum , Antifúngicos , Peptídeos Catiônicos Antimicrobianos , Doenças das Plantas
14.
Nat Commun ; 11(1): 105, 2020 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-31913271

RESUMO

Psoriasis is an inflammatory skin disease with strong neutrophil (PMN) infiltration and high levels of the antimicrobial peptide, LL37. LL37 in complex with DNA and RNA is thought to initiate disease exacerbation via plasmacytoid dendritic cells. However, the source of nucleic acids supposed to start this initial inflammatory event remains unknown. We show here that primary murine and human PMNs mount a fulminant and self-propagating neutrophil extracellular trap (NET) and cytokine response, but independently of the canonical NET component, DNA. Unexpectedly, RNA, which is abundant in NETs and psoriatic but not healthy skin, in complex with LL37 triggered TLR8/TLR13-mediated cytokine and NET release by PMNs in vitro and in vivo. Transfer of NETs to naive human PMNs prompts additional NET release, promoting further inflammation. Our study thus uncovers a self-propagating vicious cycle contributing to chronic inflammation in psoriasis, and NET-associated RNA (naRNA) as a physiologically relevant NET component.


Assuntos
Armadilhas Extracelulares/imunologia , Neutrófilos/imunologia , Psoríase/imunologia , Adulto , Animais , Peptídeos Catiônicos Antimicrobianos , Citocinas/genética , Citocinas/imunologia , Armadilhas Extracelulares/genética , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Infiltração de Neutrófilos , Psoríase/genética , RNA/genética , RNA/imunologia , Receptor 8 Toll-Like/genética , Receptor 8 Toll-Like/imunologia , Adulto Jovem
15.
J Dairy Sci ; 103(3): 2677-2684, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31954559

RESUMO

The aim of this study was to characterize the proteins present in milk whey from buffaloes with and without subclinical mastitis using a proteomic approach to identify differentially expressed proteins as potential biomarkers for this disease. Whey from Murrah buffaloes with subclinical mastitis was compared with whey from healthy animals using liquid chromatography-tandem mass spectrometry. The annotated protein databases for Bubalus bubalis and Bos taurus were used in the analysis, and the gene annotations from the buffalo and bovine reference assemblies were also used. After integrating gene annotations from both buffaloes and bovines, a total of 1,033 proteins were identified, of which 156 were differentially expressed. Eighteen biological processes were annotated with Gene Ontology. Cathelicidin-3 was identified as a potential biomarker for subclinical mastitis. These results are important to the characterization of mastitis in the buffalo mammary gland and may aid in the development of tools for early diagnosis.


Assuntos
Peptídeos Catiônicos Antimicrobianos/análise , Mastite/veterinária , Proteínas do Leite/análise , Proteômica , Soro do Leite/química , Animais , Biomarcadores/análise , Búfalos , Bovinos , Cromatografia Líquida/veterinária , Feminino , Mastite/metabolismo , Mastite Bovina/metabolismo , Espectrometria de Massas em Tandem/veterinária , Proteínas do Soro do Leite/análise
16.
World J Microbiol Biotechnol ; 36(1): 18, 2020 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-31912374

RESUMO

In this paper, we report the antimicrobial activity of AMEP412 (a protein elicitor from Bacillus subtilis) against Streptomyces scabiei, which is the potato common scab pathogen. The purified protein samples showed an obvious inhibition zone on an S. scabiei agar plate, and the minimum inhibition concentration detected was 50 µg mL-1. The fluorescence localization assay revealed that AMEP412 could bind to aerial mycelia and spores. The stability test showed that AMEP412 was stable at 60 °C for 30 min and in pH values from 5.0 to 10.0. Its antimicrobial activity was not sensitive to metal cations. However, its activity declined by 23% when treated with Proteinase K, and was completely abrogated with Tween 80 treatment. Three antimicrobial peptides (GS21, GY20 and GY23) were identified from AMEP412, which further verified its antimicrobial activity. This research reveals the antimicrobial function of AMEP412, which not only enriches the function of the protein elicitor, but also provides a candidate for the biocontrol of potato common scab.


Assuntos
Antibacterianos/farmacologia , Bacillus subtilis/metabolismo , Proteínas de Bactérias/farmacologia , Streptomyces/efeitos dos fármacos , Antibacterianos/química , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/farmacologia , Proteínas de Bactérias/química , Temperatura Alta , Concentração de Íons de Hidrogênio , Testes de Sensibilidade Microbiana , Micélio/efeitos dos fármacos , Doenças das Plantas/prevenção & controle , Solanum tuberosum/microbiologia , Esporos Bacterianos/efeitos dos fármacos , Streptomyces/crescimento & desenvolvimento
17.
Carbohydr Polym ; 232: 115786, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31952594

RESUMO

Novel nanomaterials have been developed for antimicrobial and wound healing applications. Here, we report the preparation of a polyvinyl alcohol/chitosan (PVA/CS) nanofiber with carboxymethyl chitosan nanoparticles (CMCS-OH30 NPs) encapsulating the antibacterial peptide OH-CATH30 (OH-30). The PVA/CS nanofibers containing OH-30 NPs (NP-30-NFs) obtained via electrospinning could achieve a secondary embedded OH-30. The effect of NP-30-NFs on the release of OH-30 was investigated through high-performance liquid chromatography. The antibacterial activities of NP-30-NFs against Escherichia coli and Staphylococcus aureus were studied by bacterial plate counting. NP-30-NFs containing different concentrations of NPs were applied to mouse skin wounds to determine their effectiveness in promoting wound healing. Results showed that NP-30-NFs exhibited antibacterial properties and promoted skin wound healing.


Assuntos
Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Quitosana/farmacologia , Nanofibras/química , Álcool de Polivinil/farmacologia , Cicatrização/efeitos dos fármacos , Animais , Antibacterianos/administração & dosagem , Antibacterianos/química , Peptídeos Catiônicos Antimicrobianos/administração & dosagem , Peptídeos Catiônicos Antimicrobianos/química , Quitosana/administração & dosagem , Quitosana/química , Relação Dose-Resposta a Droga , Escherichia coli/efeitos dos fármacos , Feminino , Injeções Intraperitoneais , Camundongos , Camundongos Endogâmicos , Testes de Sensibilidade Microbiana , Nanofibras/administração & dosagem , Nanopartículas/administração & dosagem , Nanopartículas/química , Tamanho da Partícula , Álcool de Polivinil/administração & dosagem , Álcool de Polivinil/química , Staphylococcus aureus/efeitos dos fármacos , Relação Estrutura-Atividade , Propriedades de Superfície
18.
Environ Pollut ; 256: 113443, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31733951

RESUMO

During their lifetime honey bees (Apis mellifera) rarely experience optimal conditions. Sometimes, a simultaneous action of multiple stressors, natural and chemical, results in even greater effect than of any stressor alone. Therefore, integrative investigations of different factors affecting honey bees have to be carried out. In this study, adult honey bees exposed to thiamethoxam in larval and/or adult stage and infected with Nosema ceranae were examined. Newly emerged bees from colonies, non-treated or treated with thiamethoxam, were organized in six groups and kept in cages. Thiamethoxam treated bees were further exposed to either thiamethoxam or Nosema (groups TT and TN), or simultaneously to both (group TTN). Newly emerged bees from non-treated colonies were exposed to Nosema (group CN). From both, treated and non-treated colonies two groups were organized and further fed only with sugar solution (groups C and TC). Here, we present the expression profile of 19 genes in adult worker honey bees comprising those involved in immune, detoxification, development and apoptosis response. Results showed that gene expression patterns changed with time and depended on the treatment. In group TC at the time of emergence the majority of tested genes were downregulated, among which nine were significantly altered. The same gene pattern was observed on day six, where the only significantly upregulated gene was defensin-1. On day nine most of analyzed genes in all experimental groups showed upregulation compared to control group, where upregulation of antimicrobial peptide genes abaecin, defensin-1 and defensin-2 was significant in groups TT and TTN. On day 15 we observed a similar pattern of expression in groups TC and TT exposed to thiamethoxam only, where most of the detoxification genes were downregulated. Additionally RNA loads of Nosema and honey bee viruses were recorded. We detected a synergistic interaction of thiamethoxam and Nosema, reflected in lowest honey bee survival.


Assuntos
Abelhas/fisiologia , Inseticidas/toxicidade , Nosema , Tiametoxam/toxicidade , Animais , Peptídeos Catiônicos Antimicrobianos , Abelhas/efeitos dos fármacos , Abelhas/microbiologia , Expressão Gênica , Infecções , Proteínas de Insetos , Larva/efeitos dos fármacos , Larva/microbiologia , Larva/fisiologia , Microsporidiose/veterinária
19.
Biochim Biophys Acta Biomembr ; 1862(2): 183141, 2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-31790693

RESUMO

Linearized esculentin 2 EM (E2EM-lin) from the frog, Glandirana emeljanovi was highly active against Gram-positive bacteria (minimum lethal concentration ≤ 5.0 µM) and strongly α-helical in the presence of lipid mimics of their membranes (>55.0%). The N-terminal α-helical structure adopted by E2EM-lin showed the potential to form a membrane interactive, tilted peptide with an hydrophobicity gradient over residues 9 to 23. E2EM-lin inserted strongly into lipid mimics of membranes from Gram-positive bacteria (maximal surface pressure changes ≥5.5 mN m-1), inducing increased rigidity (Cs-1 ↑), thermodynamic instability (ΔGmix < 0 â†’ ΔGmix > 0) and high levels of lysis (>50.0%). These effects appeared to be driven by the high anionic lipid content of membranes from Gram-positive bacteria; namely phosphatidylglycerol (PG) and cardiolipin (CL) species. The high levels of α-helicity (60.0%), interaction (maximal surface pressure change = 6.7 mN m-1) and lysis (66.0%) shown by E2EM-lin with PG species was a major driver in the ability of the peptide to lyse and kill Gram-positive bacteria. E2EM-lin also showed high levels of α-helicity (62.0%) with CL species but only low levels of interaction (maximal surface pressure change = 2.9 mN m-1) and lysis (21.0%) with the lipid. These combined data suggest that E2EM-lin has a specificity for killing Gram-positive bacteria that involves the formation of tilted structure and appears to be primarily driven by PG-mediated membranolysis. These structure/function relationships are used to help explain the pore forming process proposed to describe the membranolytic, antibacterial action of E2EM-lin.


Assuntos
Proteínas de Anfíbios/química , Peptídeos Catiônicos Antimicrobianos/química , Proteínas de Anfíbios/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Membrana Celular/efeitos dos fármacos , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Ligação Proteica , Conformação Proteica em alfa-Hélice
20.
Biochim Biophys Acta Biomembr ; 1862(2): 183092, 2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-31678367

RESUMO

Antimicrobial peptides (AMPs) are important constituents of the innate immunity system of all living organisms. They participate in the first line of defense against invading pathogens such as viruses, bacteria, and fungi. In view of the increasing difficulties to treat infectious diseases due to the emergence of antibiotic-resistant bacterial strains, AMPs have great potential to control infectious diseases in humans and animals. In this study, two small peptides, RcAlb-PepI and RcAlb-PepII, were designed based on the primary structure of Rc-2S-Alb, a 2S albumin from the seed cake of Ricinus communis, and their antimicrobial activity assessed. RcAlb-PepII strongly inhibited the growth of Klebsiella pneumoniae and Candida parapsilosis, and induced morphological alterations in their cell surface. C. parapsilosis exposed to RcAlb-PepII presented higher cell membrane permeabilization and elevated content of reactive oxygen species. RcAlb-PepII also degraded and reduced the biofilm formation in C. parapsilosis and in K. pneumonia cells. Experimentally, RcAlb-PepII was not hemolytic and had low toxicity to mammalian cells. These are advantageous characteristics, which suggest that RcAlb-PepII is safe and apparently effective for its intended use and has great potential for the future development of an antimicrobial agent with the ability to kill or inhibit K. pneumoniae and C. parapsilosis cells.


Assuntos
Anti-Infecciosos/farmacologia , Candida parapsilosis/efeitos dos fármacos , Klebsiella pneumoniae/efeitos dos fármacos , Ricinus/química , Albuminas , Anti-Infecciosos/síntese química , Peptídeos Catiônicos Antimicrobianos/síntese química , Biofilmes/efeitos dos fármacos , Candida parapsilosis/crescimento & desenvolvimento , Permeabilidade da Membrana Celular/efeitos dos fármacos , Desenho de Fármacos , Klebsiella pneumoniae/crescimento & desenvolvimento
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