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1.
Pharmaceuticals (Basel) ; 17(1)2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38256916

RESUMO

The diminishing portfolio of mankind's available antibiotics urges science to develop novel potent drugs. Here, we present a peptide fitting the typical blueprint of amphipathic and membrane-active antimicrobial peptides, denominated C14R. This 2 kDa peptide consists of 16 amino acid residues, with seven being either hydrophobic, aromatic, or non-polar, and nine being polar or positively charged, strictly separated on opposite sides of the predicted α-helix. The affinity of the peptide C14R to P. aeruginosa membranes and its intrinsic tendency to productively insert into membranes of such composition were analyzed by dynamic simulations. Its biological impact on the viability of two different P. aeruginosa reference strains was demonstrated by determining the minimal inhibitory concentrations (MICs), which were found to be in the range of 10-15 µg/mL. C14R's pore-forming capability was verified in a permeabilization assay based on the peptide-triggered uptake of fluorescent dyes into the bacterial cells. Finally, the peptide was used in radial diffusion assays, which are commonly used for susceptibility testing of antimicrobial peptides in clinical microbiology. In comparison to reference strains, six clinical P. aeruginosa isolates were clearly affected, thereby paving the way for further in-depth analyses of C14R as a promising new AMP drug in the future.

2.
Int J Mol Sci ; 24(12)2023 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-37372935

RESUMO

Antimicrobial peptides (AMPs) represent a promising class of therapeutic biomolecules that show antimicrobial activity against a broad range of microorganisms, including life-threatening pathogens. In contrast to classic AMPs with membrane-disrupting activities, new peptides with a specific anti-biofilm effect are gaining in importance since biofilms could be the most important way of life, especially for pathogens, as the interaction with host tissues is crucial for the full development of their virulence in the event of infection. Therefore, in a previous study, two synthetic dimeric derivatives (parallel Dimer 1 and antiparallel Dimer 2) of the AMP Cm-p5 showed specific inhibition of the formation of Candida auris biofilms. Here we show that these derivatives are also dose-dependently effective against de novo biofilms that are formed by the widespread pathogenic yeasts C. albicans and C. parapsilosis. Moreover, the activity of the peptides was demonstrated even against two fluconazole-resistant strains of C. auris.


Assuntos
Candida albicans , Fluconazol , Fluconazol/farmacologia , Candida parapsilosis , Antifúngicos/farmacologia , Candida , Biofilmes , Peptídeos/farmacologia , Testes de Sensibilidade Microbiana
3.
Int J Mol Sci ; 24(4)2023 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-36835264

RESUMO

Mollusks have been widely investigated for antimicrobial peptides because their humoral defense against pathogens is mainly based on these small biomolecules. In this report, we describe the identification of three novel antimicrobial peptides from the marine mollusk Nerita versicolor. A pool of N. versicolor peptides was analyzed with nanoLC-ESI-MS-MS technology, and three potential antimicrobial peptides (Nv-p1, Nv-p2 and Nv-p3) were identified with bioinformatical predictions and selected for chemical synthesis and evaluation of their biological activity. Database searches showed that two of them show partial identity to histone H4 peptide fragments from other invertebrate species. Structural predictions revealed that they all adopt a random coil structure even when placed near a lipid bilayer patch. Nv-p1, Nv-p2 and Nv-p3 exhibited activity against Pseudomonas aeruginosa. The most active peptide was Nv-p3 with an inhibitory activity starting at 1.5 µg/mL in the radial diffusion assays. The peptides were ineffective against Klebsiella pneumoniae, Listeria monocytogenes and Mycobacterium tuberculosis. On the other hand, these peptides demonstrated effective antibiofilm action against Candida albicans, Candida parapsilosis and Candida auris but not against the planktonic cells. None of the peptides had significant toxicity on primary human macrophages and fetal lung fibroblasts at effective antimicrobial concentrations. Our results indicate that N. versicolor-derived peptides represent new AMP sequences and have the potential to be optimized and developed into antibiotic alternatives against bacterial and fungal infections.


Assuntos
Anti-Infecciosos , Gastrópodes , Animais , Humanos , Peptídeos Catiônicos Antimicrobianos/farmacologia , Peptídeos Antimicrobianos , Anti-Infecciosos/farmacologia , Antibacterianos/farmacologia , Moluscos , Testes de Sensibilidade Microbiana
4.
Pharmaceutics ; 14(7)2022 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-35890228

RESUMO

In previous studies, derivatives of the peptide Pom-1, which was originally extracted from the freshwater mollusk Pomacea poeyana, showed an exceptional ability to specifically inhibit biofilm formation of the laboratory strain ATCC 90028 as a model strain of the pathogenic yeast Candida albicans. In follow-up, here, we demonstrate that the derivatives Pom-1A to Pom-1F are also active against biofilms of invasive clinical C. albicans isolates, including strains resistant against fluconazole and/or amphotericin B. However, efficacy varied strongly between the isolates, as indicated by large deviations in the experiments. This lack of robustness could be efficiently bypassed by using mixtures of all peptides. These mixed peptide preparations were active against biofilm formation of all the isolates with uniform efficacies, and the total peptide concentration could be halved compared to the original MIC of the individual peptides (2.5 µg/mL). Moreover, mixing the individual peptides restored the antifungal effect of fluconazole against fluconazole-resistant isolates even at 50% of the standard therapeutic concentration. Without having elucidated the reason for these synergistic effects of the peptides yet, both the gain of efficacy and the considerable increase in efficiency by combining the peptides indicate that Pom-1 and its derivatives in suitable formulations may play an important role as new antibiofilm antimycotics in the fight against invasive clinical infections with (multi-) resistant C. albicans.

5.
Pharmaceutics ; 14(2)2022 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-35214049

RESUMO

Antimicrobial peptides (AMPs) are an alternative group for the therapy of infectious diseases, with activity against a wide range of diverse pathogens. However, classical AMPs have significant side effects in human cells due to their unspecific pore formation in biomembranes. Nevertheless, AMPs are promising therapeutics and can be isolated from natural sources, which include sea and freshwater molluscs. The AMPs identified in these organisms show promising antimicrobial activities, as pathogens are mainly fought by innate defence mechanisms. An auspicious candidate among molluscs is the Cuban freshwater snail Pomacea poeyana, from which the peptides Pom-1 and Pom-2 have been isolated and studied. These studies revealed significant antimicrobial activities for both AMPs. Based on the activities determined, Pom-1 was used for further optimization. In order to meet the emerging requirements of improved anti-biofilm activity against naturally occurring Candida species, the six derivatives Pom-1A to F were developed and investigated. Analysis of the derivatives acting on the most abundant naturally occurring Candida yeast Candida albicans (C. albicans) revealed a strong anti-biofilm activity, especially induced by Pom-1 B, C, and D. Furthermore, a moderate decrease in the metabolic activity of planktonic yeast cells was observed.

6.
Peptides ; 146: 170644, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34464592

RESUMO

Host defense peptides (HDPs) exhibit a broad range of antimicrobial and immunomodulatory activities. In this sense, both functions are like different sides of the same coin. The direct antimicrobial side was discovered first, and widely studied for the development of anti-infective therapies. In contrast, the immunomodulatory side was recognized later and in the last 20 years the interest in this field has been continuously growing. Different to their antimicrobial activities, the immunomodulatory activities of host defense peptides are more effective in vivo. They offer a great opportunity for new therapeutic applications in the fields of anti-infective therapy, chronic inflammatory diseases treatment, novel vaccine adjuvants development and anticancer immunotherapy. These immune related functions of HDPs includes chemoattraction of leukocytes, modulation of inflammation, enhancement of antigen presentation and polarization of adaptive immune responses. Our attempt with this review is to make a careful evaluation of different aspects of the less explored, but attractive immunomodulatory side of the HDP functional coin.


Assuntos
Peptídeos Catiônicos Antimicrobianos/farmacologia , Fatores Imunológicos/farmacologia , Animais , Anti-Infecciosos/farmacologia , Humanos , Sistema Imunitário/efeitos dos fármacos
7.
Biomolecules ; 11(5)2021 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-34067685

RESUMO

Cm-p5 is a snail-derived antimicrobial peptide, which demonstrated antifungal activity against the pathogenic strains of Candida albicans. Previously we synthetized a cyclic monomer as well as a parallel and an antiparallel dimer of Cm-p5 with improved antifungal activity. Considering the alarming increase of microbial resistance to conventional antibiotics, here we evaluated the antimicrobial activity of these derivatives against multiresistant and problematic bacteria and against important viral agents. The three peptides showed a moderate activity against Pseudomonas aeruginosa, Klebsiella pneumoniae Extended Spectrum ß-Lactamase (ESBL), and Streptococcus agalactiae, with MIC values > 100 µg/mL. They exerted a considerable activity with MIC values between 25-50 µg/mL against Acinetobacter baumanii and Enterococcus faecium. In addition, the two dimers showed a moderate activity against Pseudomonas aeruginosa PA14. The three Cm-p5 derivatives inhibited a virulent extracellular strain of Mycobacterium tuberculosis, in a dose-dependent manner. Moreover, they inhibited Herpes Simplex Virus 2 (HSV-2) infection in a concentration-dependent manner, but had no effect on infection by the Zika Virus (ZIKV) or pseudoparticles of Severe Acute Respiratory Syndrome Corona Virus 2 (SARS-CoV-2). At concentrations of >100 µg/mL, the three new Cm-p5 derivatives showed toxicity on different eukaryotic cells tested. Considering a certain cell toxicity but a potential interesting activity against the multiresistant strains of bacteria and HSV-2, our compounds require future structural optimization.


Assuntos
Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/química , Antivirais/farmacologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Herpesvirus Humano 2/efeitos dos fármacos , Sequência de Aminoácidos , Animais , Antibacterianos/química , Peptídeos Catiônicos Antimicrobianos/farmacologia , Antivirais/química , Candida albicans/efeitos dos fármacos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Dimerização , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana , SARS-CoV-2/efeitos dos fármacos
8.
Antibiotics (Basel) ; 9(7)2020 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-32605024

RESUMO

Growth in biofilms as a fascinating and complex microbial lifestyle has become widely accepted as one of the key features of pathogenic microbes, to successfully express their full virulence potential and environmental persistence. This also increases the threat posed by Candida auris, which has a high intrinsic ability to persist on abiotic surfaces including those of surgical instruments and medical tubing. In a previous study, cyclic and helical-stabilized analogues of the antifungal peptide Cm-p5 were designed and synthetized, and proved to have increased activities against C. albicans and C. parapsilosis, but not against planktonic C. auris cells cultivated in suspension cultures. Here, we demonstrate, initially, that these derivatives, however, exhibited semi-inhibitory concentrations between 10-21 µg/mL toward C. auris biofilms. Maturated biofilms were also arrested between 71-97%. These novel biofilm inhibitors may open urgently needed new routes for the development of novel drugs and treatments for the next stage of fight against C. auris.

9.
Macromol Biosci ; 20(4): e2000005, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32104975

RESUMO

The pathogenic yeast Candida auris has received increasing attention due to its ability to cause fatal infections, its resistance toward important fungicides, and its ability to persist on surfaces including medical devices in hospitals. To brace health care systems for this considerable risk, alternative therapeutic approaches such as antifungal peptides are urgently needed. In clinical wound care, a significant focus has been directed toward novel surgical (wound) dressings as first defense lines against C. auris. Inspired by Cerberus the Greek mythological "hound of Hades" that prevents the living from entering and the dead from leaving hell, the preparation of a gatekeeper hybrid hydrogel is reported featuring lectin-mediated high-affinity immobilization of C. auris cells from a collagen gel as a model substratum in combination with a release of an antifungal peptide drug to kill the trapped cells. The vision is an efficient and safe two-layer medical composite hydrogel for the treatment of severe wound infections that typically occur in hospitals. Providing this new armament to the repertoire of possibilities for wound care in critical (intensive care) units may open new routes to shield and defend patients from infections and clinical facilities from spreading and invasion of C. auris and probably other fungal pathogens.


Assuntos
Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Farmacorresistência Fúngica Múltipla/efeitos dos fármacos , Hidrogéis/farmacologia , Peptídeos/farmacologia , Animais , Antifúngicos/síntese química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Bandagens , Candida/crescimento & desenvolvimento , Candida/patogenicidade , Colágeno/química , Expressão Gênica , Humanos , Hidrogéis/química , Lectinas/genética , Lectinas/metabolismo , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Metionina/química , Testes de Sensibilidade Microbiana , Compostos Organofosforados/química , Peptídeos/síntese química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Soroalbumina Bovina/química , Pele/efeitos dos fármacos , Suínos , Compostos de Tritil/química
10.
ACS Omega ; 4(21): 19081-19095, 2019 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-31763531

RESUMO

Following the information obtained by a rational design study, a cyclic and helical-stabilized analogue of the peptide Cm-p5 was synthetized. The cyclic monomer showed an increased activity in vitro against Candida albicans and Candida parapsilosis, compared to Cm-p5. Initially, 14 mutants of Cm-p5 were synthesized following a rational design to improve the antifungal activity and pharmacological properties. Antimicrobial testing showed that the activity was lost in each of these 14 analogues, suggesting, as a main conclusion, that a Glu-His salt bridge could stabilize Cm-p5 helical conformation during the interaction with the plasma membrane. A derivative, obtained by substitution of Glu and His for Cys, was synthesized and oxidized with the generation of a cyclic monomer with improved antifungal activity. In addition, two dimers were generated during the oxidation procedure, a parallel and antiparallel one. The dimers showed a helical secondary structure in water, whereas the cyclic monomer only showed this conformation in SDS. Molecular dynamic simulations confirmed the helical stabilizations for all of them, therefore indicating the possible essential role of the Glu-His salt bridge. In addition, the antiparallel dimer showed a moderate activity against Pseudomonas aeruginosa and a significant activity against Listeria monocytogenes. Neither the cyclic monomer nor the dimers were toxic against macrophages or THP-1 human cells. Due to its increased capacity for fungal control compared to fluconazole, its low cytotoxicity, together with a stabilized α-helix and disulfide bridges, that may advance its metabolic stability, and in vivo activity, the new cyclic Cm-p5 monomer represents a potential systemic antifungal therapeutic candidate.

11.
Int J Pharm ; 555: 356-367, 2019 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-30453018

RESUMO

In the last years, the antimicrobial resistance against antibiotics has become a serious health issue, arise as global threat. This has generated a search for new strategies in the progress of new antimicrobial therapies. In this context, different nanosystems with antimicrobial properties have been studied. Specifically, magnetic nanoparticles seem to be very attractive due to their relatively simple synthesis, intrinsic antimicrobial activity, low toxicity and high versatility. Iron oxide NPs (IONPs) was authorized by the World Health Organization for human used in biomedical applications such as in vivo drug delivery systems, magnetic guided therapy and contrast agent for magnetic resonance imaging have been widely documented. Furthermore, the antimicrobial activity of different magnetic nanoparticles has recently been demonstrated. This review elucidates the recent progress of IONPs in drug delivery systems and focuses on the treatment of infectious diseases and target the possible detrimental biological effects and associated safety issues.


Assuntos
Anti-Infecciosos/administração & dosagem , Sistemas de Liberação de Medicamentos , Nanopartículas de Magnetita , Animais , Anti-Infecciosos/farmacologia , Doenças Transmissíveis/tratamento farmacológico , Doenças Transmissíveis/microbiologia , Resistência Microbiana a Medicamentos , Compostos Férricos/química , Humanos
12.
Rev. cuba. med. trop ; 69(2): 1-13, may.-ago. 2017. ilus
Artigo em Espanhol | LILACS | ID: biblio-901243

RESUMO

El aumento en la incidencia de las enfermedades infecciosas en los últimos años se ha favorecido por diferentes causas. Entre estas se destacan las inmunodeficiencias adquiridas (sida, trasplantes de órganos, quimioterapia oncológica), la migración de personas que trae consigo la posibilidad de importar enfermedades hacia poblaciones susceptibles, así como el excesivo empleo de antibióticos. Debido a esta situación se ha incrementado la búsqueda de nuevos candidatos terapéuticos para el desarrollo de terapias más efectivas. En este sentido los péptidos antimicrobianos constituyen una opción promisoria, pues presentan un amplio espectro de actividad frente a varios microorganismos patógenos. Además, se encuentran ampliamente distribuidos en la naturaleza, desde organismos unicelulares hasta mamíferos. Algunos péptidos antimicrobianos ya están siendo evaluados en estudios clínicos aunque muchos de ellos no han tenido resultados favorables in vivo debido a su poca estabilidad metabólica y toxicidad, entre otros. Con el fin de optimizar estas propiedades de los péptidos antimicrobianos se han trazado diferentes estrategias como la modificación química de su estructura y la conjugación con nanopartículas magnéticas. Es por eso que este artículo tiene el objetivo de revisar las potenciales aplicaciones terapéuticas de estas moléculas, teniendo en cuenta la información publicada al respecto en MedLine, Web of Science y Scopus en los últimos años


The growing incidence of infectious disease in recent years may be attributed to several causes, among them acquired immunodeficiencies (AIDS, organ transplant, oncological chemotherapy), human migration and the consequent import of diseases into susceptible populations, and the excessive use of antibiotics. This situation has fostered the search for new therapeutic candidates for the development of more effective treatments. Antimicrobial peptides are a promising alternative in this respect, due to their broad spectrum of activity against several pathogenic microorganisms. Moreover, they are widely distributed in nature, from unicellular organisms to mammals. Some antimicrobial peptides are already being evaluated in clinical studies, though many of them have not produced any favorable results in vivo due to their low metabolic stability and their toxicity, among other factors. Several strategies have been developed to overcome the above mentioned drawbacks, among them conjugation of microbial peptides with magnetic nanoparticles and chemical modification of their structure. The present study is aimed at reviewing the potential therapeutic applications of these molecules based on information published in MedLine, the Web of Science and Scopus in recent years.

13.
Org Biomol Chem ; 15(17): 3628-3637, 2017 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-28406518

RESUMO

A multicomponent macrocyclization strategy towards cyclic lipopeptides is described. The approach relies on the utilization of the Ugi and Passerini multicomponent reactions for the cyclization of peptides and oxo-peptides, and here it is employed for the construction of a small library of analogues of the natural products mycosubtilin and surfactin A. A key feature of this method is the simultaneous incorporation of either one or two exocyclic lipid tails along with the macrocyclic ring closure, which is only possible due to the multicomponent nature of the macrocyclization step. The evaluation of the anticancer activity of the lipopeptide library showed that the installation of a second lipid moiety in the surfactin scaffold leads to a more potent cytotoxicity in cancer cells. This is a new example of the multicomponent reaction potential in rapidly producing natural product analogues for biological screening.


Assuntos
Produtos Biológicos/síntese química , Produtos Biológicos/farmacologia , Peptídeos Cíclicos/síntese química , Peptídeos Cíclicos/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Produtos Biológicos/química , Linhagem Celular Tumoral , Técnicas de Química Sintética , Ciclização , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Lipoproteínas/síntese química , Lipoproteínas/química , Lipoproteínas/farmacologia , Peptídeos Cíclicos/química
15.
Int J Nanomedicine ; 11: 3849-57, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27563243

RESUMO

Diseases caused by bacterial and fungal pathogens are among the major health problems in the world. Newer antimicrobial therapies based on novel molecules urgently need to be developed, and this includes the antimicrobial peptides. In spite of the potential of antimicrobial peptides, very few of them were able to be successfully developed into therapeutics. The major problems they present are molecule stability, toxicity in host cells, and production costs. A novel strategy to overcome these obstacles is conjugation to nanomaterial preparations. The antimicrobial activity of different types of nanoparticles has been previously demonstrated. Specifically, magnetic nanoparticles have been widely studied in biomedicine due to their physicochemical properties. The citric acid-modified manganese ferrite nanoparticles used in this study were characterized by high-resolution transmission electron microscopy, which confirmed the formation of nanocrystals of approximately 5 nm diameter. These nanoparticles were able to inhibit Candida albicans growth in vitro. The minimal inhibitory concentration was 250 µg/mL. However, the nanoparticles were not capable of inhibiting Gram-negative bacteria (Escherichia coli) or Gram-positive bacteria (Staphylococcus aureus). Finally, an antifungal peptide (Cm-p5) from the sea animal Cenchritis muricatus (Gastropoda: Littorinidae) was conjugated to the modified manganese ferrite nanoparticles. The antifungal activity of the conjugated nanoparticles was higher than their bulk counterparts, showing a minimal inhibitory concentration of 100 µg/mL. This conjugate proved to be nontoxic to a macrophage cell line at concentrations that showed antimicrobial activity.


Assuntos
Anti-Infecciosos/farmacologia , Antifúngicos/farmacologia , Ácido Cítrico/farmacologia , Materiais Revestidos Biocompatíveis/farmacologia , Compostos Férricos/farmacologia , Compostos de Manganês/farmacologia , Nanopartículas/química , Peptídeos/farmacologia , Animais , Antibacterianos/farmacologia , Antifúngicos/química , Candida albicans/efeitos dos fármacos , Candida albicans/crescimento & desenvolvimento , Proliferação de Células/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Camundongos , Testes de Sensibilidade Microbiana , Viabilidade Microbiana/efeitos dos fármacos , Nanopartículas/ultraestrutura , Células RAW 264.7 , Staphylococcus aureus/efeitos dos fármacos
16.
Biochim Biophys Acta ; 1858(7 Pt A): 1488-98, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27063608

RESUMO

Recently, several peptides have been studied regarding the defence process against pathogenic microorganisms, which are able to act against different targets, with the purpose of developing novel bioactive compounds. The present work focuses on the structural and functional evaluation of the palindromic antimicrobial peptide Pa-MAP2, designed based on the peptide Pa-MAP from Pleuronectes americanus. For a better structural understanding, molecular modelling analyses were carried out, together with molecular dynamics and circular dichroism, in different media. Antibacterial activity against Gram-negative and positive bacteria was evaluated, as well as cytotoxicity against human erythrocytes, RAW 264.7, Vero and L6 cells. In silico docking experiments, lipid vesicle studies, and atomic force microscopy (AFM) imaging were carried out to explore the activity of the peptide. In vivo studies on infected mice were also done. The palindromic primary sequence favoured an α-helix structure that was pH dependent, only present on alkaline environment, with dynamic N- and C-terminals that are stabilized in anionic media. Pa-MAP2 only showed activity against Gram-negative bacteria, with a MIC of 3.2 µM, and without any cytotoxic effect. In silico, lipid vesicles and AFM studies confirm the preference for anionic lipids (POPG, POPS, DPPE, DPPG and LPS), with the positively charged lysine residues being essential for the initial electrostatic interaction. In vivo studies showed that Pa-MAP2 increases to 100% the survival rate of mice infected with Escherichia coli. Data here reported indicated that palindromic Pa-MAP2 could be an alternative candidate for use in therapeutics against Gram-negative bacterial infections.


Assuntos
Antibacterianos/química , Peptídeos Catiônicos Antimicrobianos/química , Infecções por Escherichia coli/tratamento farmacológico , Peptidomiméticos/química , Alanina/química , Sequência de Aminoácidos , Animais , Antibacterianos/síntese química , Antibacterianos/farmacologia , Peptídeos Catiônicos Antimicrobianos/isolamento & purificação , Sobrevivência Celular/efeitos dos fármacos , Chlorocebus aethiops , Colesterol/química , Eritrócitos/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/mortalidade , Linguado/metabolismo , Humanos , Lipopolissacarídeos/química , Camundongos , Simulação de Dinâmica Molecular , Dados de Sequência Molecular , Peptidomiméticos/síntese química , Peptidomiméticos/farmacologia , Fosfatidilcolinas/química , Fosfatidilgliceróis/química , Fosfatidilserinas/química , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Análise de Sobrevida , Lipossomas Unilamelares/química , Células Vero
17.
Org Lett ; 17(11): 2728-31, 2015 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-25994574

RESUMO

A new solid-phase protocol for the synthesis of N-substituted and tetrazolo peptides is described. The strategy relies on the combination of aminocatalysis-mediated on-resin Ugi reactions and peptide couplings for the N-alkylation of peptides at selected sites, including the N-terminal double lipidation, the simultaneous lipidation/biotinylation, and the steroid/lipid conjugation via tetrazole ring formation. The solid-phase Ugi four-component reactions were enabled by on-resin transimination steps prior to addition of the acid and isocyanide components. The strategy proved to be suitable for the feasible incorporation of complex N-substituents at both termini and at internal positions, which is not easily achievable by other solid-phase methods.


Assuntos
Lipopeptídeos/síntese química , Esteroides/química , Tetrazóis/síntese química , Alquilação , Lipopeptídeos/química , Estrutura Molecular , Técnicas de Síntese em Fase Sólida , Tetrazóis/química
18.
FASEB J ; 29(8): 3315-25, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25921828

RESUMO

Antimicrobial peptides form part of the first line of defense against pathogens for many organisms. Current treatments for fungal infections are limited by drug toxicity and pathogen resistance. Cm-p5 (SRSELIVHQRLF), a peptide derived from the marine mollusk Cenchritis muricatus peptide Cm-p1, has a significantly increased fungistatic activity against pathogenic Candida albicans (minimal inhibitory concentration, 10 µg/ml; EC50, 1.146 µg/ml) while exhibiting low toxic effects against a cultured mammalian cell line. Cm-p5 as characterized by circular dichroism and nuclear magnetic resonance revealed an α-helical structure in membrane-mimetic conditions and a tendency to random coil folding in aqueous solutions. Additional studies modeling Cm-p5 binding to a phosphatidylserine bilayer in silico and isothermal titration calorimetry using lipid monophases demonstrated that Cm-p5 has a high affinity for the phospholipids of fungal membranes (phosphatidylserine and phosphatidylethanolamine), only moderate interactions with a mammalian membrane phospholipid, low interaction with ergosterol, and no interaction with chitin. Adhesion of Cm-p5 to living C. albicans cells was confirmed by fluorescence microscopy with FITC-labeled peptide. In a systemic candidiasis model in mice, intraperitoneal administration of Cm-p5 was unable to control the fungal kidney burden, although its low amphiphaticity could be modified to generate new derivatives with improved fungicidal activity and stability.


Assuntos
Antifúngicos/farmacologia , Gastrópodes/metabolismo , Moluscos/metabolismo , Peptídeos/farmacologia , Animais , Candida albicans/efeitos dos fármacos , Candidíase/tratamento farmacológico , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Dicroísmo Circular/métodos , Feminino , Interações Hidrofóbicas e Hidrofílicas , Camundongos , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana/métodos , Fosfatidiletanolaminas/metabolismo , Fosfatidilserinas/metabolismo , Fosfolipídeos/metabolismo , Estrutura Secundária de Proteína
19.
Nanoscale ; 7(14): 6238-46, 2015 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-25776264

RESUMO

Candida albicans is a common human-pathogenic fungal species with the ability to cause several diseases including surface infections. Despite the clear difficulties of Candida control, antimicrobial peptides (AMPs) have emerged as an alternative strategy for fungal control. In this report, different concentrations of antifungal Cm-p1 (Cencritchis muricatus peptide 1) were electrospun into nanofibers for drug delivery. The nanofibers were characterized by mass spectrometry confirming the presence of the peptide on the scaffold. Atomic force microscopy and scanning electronic microscopy were used to measure the diameters, showing that Cm-p1 affects fiber morphology as well as the diameter and scaffold thickness. The Cm-p1 release behavior from the nanofibers demonstrated peptide release from 30 min to three days, leading to effective yeast control in the first 24 hours. Moreover, the biocompatibility of the fibers were evaluated through a MTS assay as well as ROS production by using a HUVEC model, showing that the fibers do not affect cell viability and only nanofibers containing 10% Cm-p1-PVA improved ROS generation. In addition, the secretion of pro-inflammatory cytokines IL-6 and TNF-α by the HUVECs was also slightly modified by the 10% Cm-p1-PVA nanofibers. In conclusion, the electrospinning technique applied here allowed for the manufacture of biodegradable biomimetic nanofibrous extracellular membranes with the ability to control fungal infection.


Assuntos
Antifúngicos , Organismos Aquáticos/química , Candida albicans/crescimento & desenvolvimento , Células Endoteliais da Veia Umbilical Humana/metabolismo , Nanofibras/química , Peptídeos , Antifúngicos/química , Antifúngicos/farmacologia , Preparações de Ação Retardada/química , Preparações de Ação Retardada/farmacologia , Células Endoteliais da Veia Umbilical Humana/citologia , Humanos , Interleucina-6/metabolismo , Teste de Materiais/métodos , Microscopia de Força Atômica , Nanofibras/ultraestrutura , Peptídeos/química , Peptídeos/farmacologia , Fator de Necrose Tumoral alfa/metabolismo
20.
Front Microbiol ; 4: 389, 2013 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-24409171

RESUMO

Lipopolysaccharides (LPSs) are the major molecular component of the outer membrane of Gram-negative bacteria. This molecule is recognized as a sign of bacterial infection, responsible for the development of local inflammatory response and, in extreme cases, septic shock. Unfortunately, despite substantial advances in the pathophysiology of sepsis, there is no efficacious therapy against this syndrome yet. As a consequence, septic shock syndrome continues to increase, reaching mortality rates over 50% in some cases. Even though many preclinical studies and clinical trials have been conducted, there is no Food and Drug Administration-approved drug yet that interacts directly against LPS. Cationic host-defense peptides (HDPs) could be an alternative solution since they possess both antimicrobial and antiseptic properties. HDPs are small, positively charged peptides which are evolutionarily conserved components of the innate immune response. In fact, binding to diverse chemotypes of LPS and inhibition of LPS-induced pro-inflammatory cytokines from macrophages have been demonstrated for different HDPs. Curiously, none of them have been isolated by their affinity to LPS. A diversity of supports could be useful for such biological interaction and suitable for isolating HDPs that recognize LPS. This approach could expand the rational search for anti-LPS HDPs.

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