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1.
J Mol Model ; 26(9): 231, 2020 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-32789582

RESUMO

The complement system plays a major role in human immunity, but its abnormal activation can have severe pathological impacts. By mimicking a natural mechanism of complement regulation, the small peptide compstatin has proven to be a very promising complement inhibitor. Over the years, several compstatin analogs have been created, with improved inhibitory potency. A recent analog is being developed as a candidate drug against several pathological conditions, including COVID-19. However, the reasons behind its higher potency and increased binding affinity to complement proteins are not fully clear. This computational study highlights the mechanistic properties of several compstatin analogs, thus complementing previous experimental studies. We perform molecular dynamics simulations involving six analogs alone in solution and two complexes with compstatin bound to complement component 3. These simulations reveal that all the analogs we consider, except the original compstatin, naturally adopt a pre-bound conformation in solution. Interestingly, this set of analogs adopting a pre-bound conformation includes analogs that were not known to benefit from this behavior. We also show that the most recent compstatin analog (among those we consider) forms a stronger hydrogen bond network with its complement receptor than an earlier analog.


Assuntos
Antivirais/química , Complemento C3/antagonistas & inibidores , Peptídeos Cíclicos/química , Peptídeos Cíclicos/metabolismo , Antivirais/metabolismo , Complemento C3/metabolismo , Infecções por Coronavirus/tratamento farmacológico , Humanos , Ligação de Hidrogênio , Simulação de Dinâmica Molecular , Pandemias , Pneumonia Viral/tratamento farmacológico , Relação Estrutura-Atividade
2.
Int J Food Microbiol ; 330: 108783, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-32659523

RESUMO

The contamination of Aspergillus carbonarius causes decreases and great decay of agricultural products, and threatens the human and animal health by producing mycotoxins, especially ochratoxin A. Bacillus subtilis has been proved to efficiently inhibit the growth of A. carbonarius. Revealing the major active compound and the mechanisms for the antifungal of B. subtilis are essential to enhance its antifungal activity and control the quality of antifungal products made of it. In this study, we determined that iturin A is the major compound that inhibits Aspergillus carbonarius, a widespread fungal pathogen of grape and other fruits. Iturin A significantly inhibited growth and ochratoxin A production of A. carbonarius with minimal inhibitory concentrations (MICs) of 10 µg/mL and 0.312 µg/mL, respectively. Morphological observations revealed that iturin A caused swelling of the fungal cells and thinning of the cell wall and membrane at 1/2 MIC, whereas it inhibited fungal spore germination and caused mitochondrial swelling at higher concentrations. A differential transcriptomic analysis indicated that the mechanisms used by iturin A to inhibit A. carbonarius were to downregulate the expression of genes related to cell membrane, transport, osmotic pressure, oxidation-reduction processes, and energy metabolism. Among the down-regulated genes, those related to the transport capacity were most significantly influenced, including the increase of energy-related transport pathways and decrease of other pathways. Notably, the genes related to taurine and hypotaurine metabolism were also decreased, indicating iturin A potentially cause the occurrence of osmotic imbalance in A. carbonarius, which may be the intrinsic cause for the swelling of fungal cells and mitochondria. Overall, iturin A produced by B. subtilis played important roles to inhibit A. carbonarius via changing the fungal cell structure and causing perturbations to energy, transport and osmotic pressure metabolisms in fungi. The results indicated a new direction for researches on the mechanisms for lipopeptides and provided useful information to develop more efficient antifungal agents, which are important to agriculture and biomedicine.


Assuntos
Antifúngicos/farmacologia , Aspergillus/efeitos dos fármacos , Aspergillus/metabolismo , Bacillus subtilis/metabolismo , Peptídeos Cíclicos/farmacologia , Antifúngicos/metabolismo , Aspergillus/genética , Aspergillus/crescimento & desenvolvimento , Transporte Biológico/efeitos dos fármacos , Transporte Biológico/genética , Metabolismo Energético/efeitos dos fármacos , Metabolismo Energético/genética , Regulação Fúngica da Expressão Gênica/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Micotoxinas/metabolismo , Pressão Osmótica/efeitos dos fármacos , Peptídeos Cíclicos/metabolismo , Esporos Fúngicos/efeitos dos fármacos , Esporos Fúngicos/crescimento & desenvolvimento , Esporos Fúngicos/metabolismo , Transcriptoma
3.
J Med Chem ; 63(10): 5274-5286, 2020 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-32364733

RESUMO

The cyclic dimeric peptide 1229U91 (GR231118) has an unusual structure and displays potent, insurmountable antagonism of the Y1 receptor. To probe the structural basis for this activity, we have prepared ring size variants and heterodimeric compounds, identifying the specific residues underpinning the mechanism of 1229U91 binding. The homodimeric structure was shown to be dispensible, with analogues lacking key pharmacophoric residues in one dimer arm retaining high antagonist affinity. Compounds 11d-h also showed enhanced Y1R selectivity over Y4R compared to 1229U91.


Assuntos
Neuropeptídeos/química , Neuropeptídeos/metabolismo , Peptídeos Cíclicos/química , Peptídeos Cíclicos/metabolismo , Receptores de Neuropeptídeo Y/metabolismo , Animais , Células CHO , Cricetinae , Cricetulus , Relação Dose-Resposta a Droga , Células HEK293 , Humanos , Neuropeptídeos/farmacologia , Peptídeos Cíclicos/farmacologia , Multimerização Proteica/efeitos dos fármacos , Multimerização Proteica/fisiologia , Receptores de Neuropeptídeo Y/antagonistas & inibidores
4.
Ann Biol Clin (Paris) ; 78(2): 201-205, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32319950

RESUMO

Anti-citrullinated cyclic peptide antibodies (ACPA) were initially considered very specific for the diagnosis of rheumatoid arthritis (RA), and can predict the prognosis of the disease. However, these antibodies can be detected in other autoimmune diseases, including systemic lupus erythematosus (SLE), the most common manifestation of which is inflammatory arthritis, which is often found in early-stage rheumatoid arthritis. The aim of our study is to evaluate the prevalence of ACPA antibodies and to analyze the profiles of their associations with autoantibodies specific to lupus, in order to look for a possible rhupus overlap syndrome in our patients. This is a retrospective study, carried out at the immunology unit, at Blida University Hospital, Algeria, involving 96 lupus patients, diagnosed according to the criteria of the American college of rheumatology (ACR). ACPA have been identified by the ELISA technique. ACPA was positive in 14,56% of our patients, whereas anti-DNA, anti-Sm and rheumatoid factor (RF) autoantibodies were positive, respectively in 47.09%, 35.41%, and in 26.04% of our patients. In addition, the presence of ACPA with anti DNA was found in 12.5% of patients. Of the 14 with ACPA+, 57.14% had arthritis. Our results confirm that ACPA auto-antibodies do not represent a pathognomonic criterion of RA. This sometimes makes the differential diagnosis with lupus difficult especially at the beginning of the disease.


Assuntos
Artrite Reumatoide/sangue , Biomarcadores/sangue , Lúpus Eritematoso Sistêmico/sangue , Lúpus Eritematoso Sistêmico/epidemiologia , Fator Reumatoide/sangue , Adolescente , Adulto , Idoso , Argélia/epidemiologia , Anticorpos Antinucleares/análise , Anticorpos Antinucleares/sangue , Artrite Reumatoide/epidemiologia , Autoanticorpos/análise , Autoanticorpos/sangue , Biomarcadores/análise , Criança , Citrulinação , Comorbidade , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Peptídeos Cíclicos/imunologia , Peptídeos Cíclicos/metabolismo , Estudos Retrospectivos , Fator Reumatoide/análise , Adulto Jovem
5.
Nat Commun ; 11(1): 1575, 2020 03 27.
Artigo em Inglês | MEDLINE | ID: mdl-32221295

RESUMO

Asparaginyl endopeptidases (AEPs) catalyze the key backbone cyclization step during the biosynthesis of plant-derived cyclic peptides. Here, we report the identification of two AEPs from Momordica cochinchinensis and biochemically characterize MCoAEP2 that catalyzes the maturation of trypsin inhibitor cyclotides. Recombinantly produced MCoAEP2 catalyzes the backbone cyclization of a linear cyclotide precursor (MCoTI-II-NAL) with a kcat/Km of 620 mM-1 s-1, making it one of the fastest cyclases reported to date. We show that MCoAEP2 can mediate both the N-terminal excision and C-terminal cyclization of cyclotide precursors in vitro. The rate of cyclization/hydrolysis is primarily influenced by varying pH, which could potentially control the succession of AEP-mediated processing events in vivo. Furthermore, MCoAEP2 efficiently catalyzes the backbone cyclization of an engineered MCoTI-II analog with anti-angiogenic activity. MCoAEP2 provides enhanced synthetic access to structures previously inaccessible by direct chemistry approaches and enables the wider application of trypsin inhibitor cyclotides in biotechnology applications.


Assuntos
Biocatálise , Cisteína Endopeptidases/metabolismo , Inibidores da Tripsina/metabolismo , Sequência de Aminoácidos , Ciclização , Concentração de Íons de Hidrogênio , Cinética , Modelos Moleculares , Peptídeos Cíclicos/química , Peptídeos Cíclicos/metabolismo , Proteínas de Plantas/metabolismo , Engenharia de Proteínas , Proteínas Recombinantes/metabolismo , Especificidade por Substrato
6.
Biochem Biophys Res Commun ; 524(4): 1051-1056, 2020 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-32070489

RESUMO

Cellular interactions with the microenvironment are mediated by ligand-receptor bonds. Such ligand-receptor bond dynamics is known to be heavily dependent on the loading rate. However, the physiologically-relevant loading rate of living cells remains unknown. Here, using a quartz crystal microbalance (QCM), we developed a bulk-force sensing platform to semi-quantitatively detect the rate of cellular force application during early stages of cell adhesion and spreading. Atop an Au-coated quartz crystal, covalently linked self-assembled monolayers (SAM) were used to immobilize cyclic-RGDfK peptides that can interact with the αvß3 integrins on cells. The QCM detects the changes in resonant frequency of the vibrating crystal due to the cellular activity/probing (force application) on the QCM surface. The corresponding changes in mass on the surface, proportional to the rate of force application, arise from the cellular interactions with the functionalized surface were calculated. The loading rate of living cells was found to be ∼80-115 pN/s. Collectively, our results revealed a fundamental feature of cell adhesion and spreading providing valuable information regarding cellular interactions with the extracellular matrix.


Assuntos
Adesão Celular , Integrina alfaVbeta3/metabolismo , Peptídeos Cíclicos/metabolismo , Técnicas de Microbalança de Cristal de Quartzo/métodos , Animais , Células CHO , Cricetulus , Eletrodos , Desenho de Equipamento , Técnicas de Microbalança de Cristal de Quartzo/instrumentação
7.
J Med Chem ; 63(4): 1576-1596, 2020 02 27.
Artigo em Inglês | MEDLINE | ID: mdl-32003991

RESUMO

Human cathepsin D (CatD), a pepsin-family aspartic protease, plays an important role in tumor progression and metastasis. Here, we report the development of biomimetic inhibitors of CatD as novel tools for regulation of this therapeutic target. We designed a macrocyclic scaffold to mimic the spatial conformation of the minimal pseudo-dipeptide binding motif of pepstatin A, a microbial oligopeptide inhibitor, in the CatD active site. A library of more than 30 macrocyclic peptidomimetic inhibitors was employed for scaffold optimization, mapping of subsite interactions, and profiling of inhibitor selectivity. Furthermore, we solved high-resolution crystal structures of three macrocyclic inhibitors with low nanomolar or subnanomolar potency in complex with CatD and determined their binding mode using quantum chemical calculations. The study provides a new structural template and functional profile that can be exploited for design of potential chemotherapeutics that specifically inhibit CatD and related aspartic proteases.


Assuntos
Catepsina D/antagonistas & inibidores , Catepsina D/metabolismo , Peptídeos Cíclicos/química , Peptídeos Cíclicos/metabolismo , Inibidores de Proteases/química , Inibidores de Proteases/metabolismo , Sítios de Ligação , Materiais Biomiméticos/síntese química , Materiais Biomiméticos/química , Materiais Biomiméticos/metabolismo , Materiais Biomiméticos/toxicidade , Células CACO-2 , Catepsina D/química , Ensaios Enzimáticos , Humanos , Cinética , Estrutura Molecular , Pepstatinas/química , Peptídeos Cíclicos/síntese química , Peptídeos Cíclicos/toxicidade , Inibidores de Proteases/síntese química , Inibidores de Proteases/toxicidade , Ligação Proteica , Relação Estrutura-Atividade
8.
Nature ; 578(7796): 582-587, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32051588

RESUMO

Addressing the ongoing antibiotic crisis requires the discovery of compounds with novel mechanisms of action that are capable of treating drug-resistant infections1. Many antibiotics are sourced from specialized metabolites produced by bacteria, particularly those of the Actinomycetes family2. Although actinomycete extracts have traditionally been screened using activity-based platforms, this approach has become unfavourable owing to the frequent rediscovery of known compounds. Genome sequencing of actinomycetes reveals an untapped reservoir of biosynthetic gene clusters, but prioritization is required to predict which gene clusters may yield promising new chemical matter2. Here we make use of the phylogeny of biosynthetic genes along with the lack of known resistance determinants to predict divergent members of the glycopeptide family of antibiotics that are likely to possess new biological activities. Using these predictions, we uncovered two members of a new functional class of glycopeptide antibiotics-the known glycopeptide antibiotic complestatin and a newly discovered compound we call corbomycin-that have a novel mode of action. We show that by binding to peptidoglycan, complestatin and corbomycin block the action of autolysins-essential peptidoglycan hydrolases that are required for remodelling of the cell wall during growth. Corbomycin and complestatin have low levels of resistance development and are effective in reducing bacterial burden in a mouse model of skin MRSA infection.


Assuntos
Antibacterianos , Descoberta de Drogas , Peptídeos Cíclicos , Peptidoglicano/efeitos dos fármacos , Peptidoglicano/metabolismo , Actinobacteria/química , Actinobacteria/genética , Actinobacteria/metabolismo , Animais , Antibacterianos/química , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Vias Biossintéticas/genética , Parede Celular/metabolismo , Clorofenóis/química , Clorofenóis/metabolismo , Clorofenóis/farmacologia , Modelos Animais de Doenças , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Resistência Microbiana a Medicamentos/genética , Feminino , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Camundongos , Testes de Sensibilidade Microbiana , Família Multigênica , N-Acetil-Muramil-L-Alanina Amidase/antagonistas & inibidores , Peptídeos Cíclicos/química , Peptídeos Cíclicos/metabolismo , Peptídeos Cíclicos/farmacologia , Filogenia , Pele/microbiologia , Infecções Estafilocócicas/microbiologia
9.
J Biol Chem ; 295(9): 2866-2884, 2020 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-31959628

RESUMO

Aberrant Ras signaling drives 30% of cancers, and inhibition of the Rho family small GTPase signaling has been shown to combat Ras-driven cancers. Here, we present the discovery of a 16-mer cyclic peptide that binds to Cdc42 with nanomolar affinity. Affinity maturation of this sequence has produced a panel of derived candidates with increased affinity and modulated specificity for other closely-related small GTPases. The structure of the tightest binding peptide was solved by NMR, and its binding site on Cdc42 was determined. Addition of a cell-penetrating sequence allowed the peptides to access the cell interior and engage with their target(s), modulating signaling pathways. In Ras-driven cancer cell models, the peptides have an inhibitory effect on proliferation and show suppression of both invasion and motility. As such, they represent promising candidates for Rho-family small GTPase inhibitors and therapeutics targeting Ras-driven cancers. Our data add to the growing literature demonstrating that peptides are establishing their place in the biologics arm of drug discovery.


Assuntos
Descoberta de Drogas , Peptídeos Cíclicos/farmacologia , Transdução de Sinais/efeitos dos fármacos , Proteína cdc42 de Ligação ao GTP/antagonistas & inibidores , Proteínas ras/metabolismo , Sítios de Ligação , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Peptídeos Penetradores de Células , GTP Fosfo-Hidrolases/antagonistas & inibidores , Humanos , Estrutura Molecular , Invasividade Neoplásica/prevenção & controle , Neoplasias/tratamento farmacológico , Peptídeos Cíclicos/química , Peptídeos Cíclicos/metabolismo , Proteína cdc42 de Ligação ao GTP/metabolismo
10.
Chem Commun (Camb) ; 56(7): 1082-1084, 2020 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-31894763

RESUMO

G-quadruplexes (G4) are non-canonical nucleic acid structures with important implications in biology. Based on an α-helical fragment of the RHAU helicase that displays high specificity for parallel-stranded G-quadrplexes, herein we demonstrate its head-to-tail cyclization by a high-efficiency ligase. The cyclic peptide exhibits superior stability and binding affinity to a G-quadruplex, and can serve as an excellent investigational tool for chemical biology applications.


Assuntos
RNA Helicases DEAD-box/metabolismo , DNA/metabolismo , Quadruplex G , Fragmentos de Peptídeos/metabolismo , Peptídeos Cíclicos/metabolismo , Células A549 , Ciclização , RNA Helicases DEAD-box/química , DNA/genética , Humanos , Oldenlandia/enzimologia , Fragmentos de Peptídeos/química , Peptídeo Sintases/química , Peptídeos Cíclicos/síntese química , Ligação Proteica , Estabilidade Proteica
11.
J Med Chem ; 63(10): 5013-5030, 2020 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-31841625

RESUMO

Heterotrimeric G proteins are molecular switches in GPCR signaling pathways and regulate a plethora of physiological and pathological processes. GPCRs are efficient drug targets, and more than 30% of the drugs in use target them. However, selectively targeting an individual GPCR may be undesirable in various multifactorial diseases in which multiple receptors are involved. In addition, abnormal activation or expression of G proteins is frequently associated with diseases. Furthermore, G proteins harboring mutations often result in malignant diseases. Thus, targeting G proteins instead of GPCRs might provide alternative approaches for combating these diseases. In this review, we discuss the biochemistry of heterotrimeric G proteins, describe the G protein-associated diseases, and summarize the currently known modulators that can regulate the activities of G proteins. The outlook for targeting G proteins to treat diverse diseases is also included in this manuscript.


Assuntos
Sistemas de Liberação de Medicamentos/tendências , Descoberta de Drogas/tendências , Proteínas Heterotriméricas de Ligação ao GTP/metabolismo , Receptores Acoplados a Proteínas-G/metabolismo , Animais , Asma/tratamento farmacológico , Asma/metabolismo , Toxinas Bacterianas/administração & dosagem , Toxinas Bacterianas/metabolismo , Sistemas de Liberação de Medicamentos/métodos , Descoberta de Drogas/métodos , Insuficiência Cardíaca/tratamento farmacológico , Insuficiência Cardíaca/metabolismo , Proteínas Heterotriméricas de Ligação ao GTP/antagonistas & inibidores , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Peptídeos Cíclicos/administração & dosagem , Peptídeos Cíclicos/metabolismo , Estrutura Secundária de Proteína , Receptores Acoplados a Proteínas-G/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Trombose/tratamento farmacológico , Trombose/metabolismo
12.
Colloids Surf B Biointerfaces ; 185: 110595, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31735419

RESUMO

The interaction between the cinnamycin and the biomimetic membranes was studied using the atomic force microscope(AFM). The bilayer was composed of the monolayer tethered on the gold surface and the outer layer fused with the vesicles on the monolayer. The vesicles were prepared at the desired ratio of dioleoylphosphatidylethanolamine(DOPE) to dioleoylphosphatidylcholine(DOPC). On the bilayer, the surface force measurement was performed with the cinnamycin immobilized covalently on the tip surface. The immobilization led to the presence of the adhesion, which was found while the tip was retracted from the bilayer. In addition, the magnitude of the adhesive force was changed with respect to the composition of DOPE in the outer layer. The difference in the adhesion may be attributed to the mean-molecular-area of DOPE and the specific-binding density on the outer layer. Furthermore, the analysis of the rupture force with respect to the loading rate indicated that the rupture length was around 0.1∼0.13 nm, which was similar to that of a van der Waals bond.


Assuntos
Bacteriocinas/química , Materiais Biomiméticos/química , Bicamadas Lipídicas/química , Membranas Artificiais , Peptídeos Cíclicos/química , Fosfatidilcolinas/química , Fosfatidiletanolaminas/química , Bacteriocinas/metabolismo , Materiais Biomiméticos/metabolismo , Bicamadas Lipídicas/metabolismo , Peptídeos Cíclicos/metabolismo , Fosfatidilcolinas/metabolismo , Fosfatidiletanolaminas/metabolismo
13.
Chem Commun (Camb) ; 56(1): 46-49, 2019 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-31768506

RESUMO

We present the synthesis and transmembrane transport properties of a new family of tris-pyridine-decorated cyclic peptides. These molecules are designed to self-assemble into dimeric shuttles in nonpolar media, which act as symport ionophores in which, apparently, the tris-pyridine scaffold complexes both cations and anions with high potency and efficacy.


Assuntos
Ionóforos/metabolismo , Bicamadas Lipídicas/metabolismo , Peptídeos Cíclicos/metabolismo , Piridinas/metabolismo , Lipossomas Unilamelares/metabolismo , Cálcio/metabolismo , Cloretos/metabolismo , Concentração de Íons de Hidrogênio , Ionóforos/síntese química , Ionóforos/química , Peptídeos Cíclicos/síntese química , Peptídeos Cíclicos/química , Piridinas/síntese química , Piridinas/química
14.
Int J Mol Sci ; 20(23)2019 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-31771178

RESUMO

Breast cancer is the second most common cause of cancer-related mortality among women around the world. Conventional treatments in the fight against breast cancer, such as chemotherapy, are being challenged regarding their effectiveness. Thus, strategies for the treatment of breast cancer need to be continuously refined to achieve a better patient outcome. We know that a number of bacteria are pathogenic and some are even associated with tumor development, however, recent studies have demonstrated interesting results suggesting some bacteria may have potential for cancer therapy. Therefore, the therapeutic role of bacteria has aroused attention in medical and pharmaceutical studies. Furthermore, genetic engineering has been used in bacterial therapy and may led to greater efficacy with few side effects. Some genetically modified non-pathogenic bacterial species are more successful due to their selectivity for cancer cells but with low toxicity for normal cells. Some live, attenuated, or genetically modified bacterias are capable to multiply in tumors and inhibit their growth. This article aims to review the role of bacteria and their products including bacterial peptides, bacteriocins, and toxins for the treatment of breast cancer.


Assuntos
Neoplasias da Mama/metabolismo , Neoplasias da Mama/terapia , Animais , Bactérias/metabolismo , Bacteriocinas/metabolismo , Colicinas/metabolismo , Humanos , Nisina/metabolismo , Peptídeos Cíclicos/metabolismo
15.
Int J Pharm ; 572: 118789, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31726199

RESUMO

The levels of microRNAs (miRNAs) are altered in various diseases including glioblastoma (GBM) and this alteration may have widespread effects on various hallmarks of cancer cells. MiR210 is overexpressed in GBM and functions as an oncogenic miRNA. Anti-miR210 therapy holds great promise but its efficient delivery remains a major challenge. Our work here explores a novel role of Tachyplesin (Tpl), a cell-penetrating antimicrobial peptide, as a nanocarrier for anti-miR210. Tpl electrostatically interacts with anti-miR210 at 1:25 and 1:50 (anti-miR:Tpl) weight ratios to form a complex and efficiently delivers anti-miR210 inside GBM cells cultured as 2D and 3D spheroid model. Treatment of GBM cells with the complex significantly inhibited miR210 levels (~90%), proliferation, migration and spheroid formation ability and induced apoptosis as evident by increased levels of caspase 3/7 and ROS. GBM cells pre-treated with anti-miR210:Tpl complex were also found to be sensitive to TMZ mediated action. Uptake of the complex in GBM cells induced the levels of miR210 targeted tumor suppressor genes, NeuroD2 and HIF3A. Overall, our work reveals a novel and efficient miRNA delivery ability of Tpl in glioma cells, holding a great promise for treatment of GBM and potentially for other cancers.


Assuntos
Antagomirs/farmacologia , Peptídeos Catiônicos Antimicrobianos/metabolismo , Antineoplásicos/farmacologia , Neoplasias Encefálicas/tratamento farmacológico , Peptídeos Penetradores de Células/metabolismo , Proteínas de Ligação a DNA/metabolismo , Portadores de Fármacos , Glioblastoma/tratamento farmacológico , MicroRNAs/antagonistas & inibidores , Peptídeos Cíclicos/metabolismo , Antagomirs/química , Antagomirs/genética , Antagomirs/metabolismo , Peptídeos Catiônicos Antimicrobianos/química , Antineoplásicos/química , Antineoplásicos/metabolismo , Antineoplásicos Alquilantes/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Caspase 3/metabolismo , Caspase 7/metabolismo , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Peptídeos Penetradores de Células/química , Proteínas de Ligação a DNA/química , Composição de Medicamentos , Regulação Neoplásica da Expressão Gênica , Glioblastoma/genética , Glioblastoma/metabolismo , Glioblastoma/patologia , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Peptídeos Cíclicos/química , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Temozolomida/farmacologia
16.
ACS Chem Biol ; 14(12): 2683-2690, 2019 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-31674754

RESUMO

Prenylation is a common step in the biosynthesis of many natural products and plays an important role in increasing their structural diversity and enhancing biological activity. Muscoride A is a linear peptide alkaloid that contain two contiguous oxazoles and unusual prenyl groups that protect the amino- and carboxy-termini. Here we identified the 12.7 kb muscoride (mus) biosynthetic gene clusters from Nostoc spp. PCC 7906 and UHCC 0398. The mus biosynthetic gene clusters encode enzymes for the heterocyclization, oxidation, and prenylation of the MusE precursor protein. The mus biosynthetic gene clusters encode two copies of the cyanobactin prenyltransferase, MusF1 and MusF2. The predicted tetrapeptide substrate of MusF1 and MusF2 was synthesized through a novel tandem cyclization route in only eight steps. Biochemical assays demonstrated that MusF1 acts on the carboxy-terminus while MusF2 acts on the amino-terminus of the tetrapeptide substrate. We show that the MusF2 enzyme catalyzes the reverse or forward prenylation of amino-termini from Nostoc spp. PCC 7906 and UHCC 0398, respectively. This finding expands the regiospecific chemical functionality of cyanobactin prenyltransferases and the chemical diversity of the cyanobactin family of natural products to include bis-prenylated polyoxazole linear peptides.


Assuntos
Oxazóis/metabolismo , Pirrolidinas/metabolismo , Vias Biossintéticas/genética , Dimetilaliltranstransferase/genética , Dimetilaliltranstransferase/metabolismo , Família Multigênica , Peptídeos Cíclicos/metabolismo , Prenilação
17.
Appl Microbiol Biotechnol ; 103(21-22): 8987-8999, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31637491

RESUMO

This study evaluated the inhibition and interaction of Bacillus velezensis BvL03 as a probiotic agent against Aeromonas hydrophila. Strain BvL03 isolated from sediment samples of fish ponds had excellent antimicrobial activity against several fish pathogenic bacteria, especially Aeromonas, including A. hydrophila, A. veronii, A. caviae, and A. sobria. The successful amplification of lipopeptide antimicrobial chemical biosynthetic genes, including iturin family (ituA, ituB, and ituD), bacillomycin family (bacA, bacD, and bacAB), surfactin family (srfAB, srfC, and srfAA), and subtilosin family (albF and sunT) from the genome of BvL03 strain, confirmed its predominant antimicrobial activity. The challenge test suggested that BvL03 significantly decreased fish mortality when challenged with A. hydrophila, which had a cumulative mortality of 12.5% in the treatment group. Toxicity and hemolytic activity of A. hydrophila after co-cultured with BvL03 were relieved as confirmed by the cell experiments, when the initial inoculated concentration of BvL03 was 109 cfu/mL or higher. Moreover, the BvL03 strain labeled with GFP protein (BvL03-GFP) and AhX040 strain labeled with mCherry protein (AhX040-mCherry) were injected into grass carps. The fluorescence levels were monitored by using In Vivo Imaging System (IVIS), in which the green color was steadily increasing, whereas the red color was gradually weakening. Whole genome sequencing revealed that strain BvL03 possesses 15 gene clusters related to antibacterial compounds, including 5 NRPS gene clusters and 3 PKS gene clusters. These results suggested that B. velezensis BvL03 has the potential to be developed as a probiotic candidate against A. hydrophila infection in aquaculture.


Assuntos
Aeromonas hydrophila/fisiologia , Antibiose/fisiologia , Bacillus/fisiologia , Agentes de Controle Biológico/metabolismo , Carpas/microbiologia , Doenças dos Peixes/microbiologia , Animais , Peptídeos Catiônicos Antimicrobianos/genética , Peptídeos Catiônicos Antimicrobianos/metabolismo , Bacteriocinas/genética , Bacteriocinas/metabolismo , Doenças dos Peixes/prevenção & controle , Lipopeptídeos/genética , Lipopeptídeos/metabolismo , Peptídeos Cíclicos/genética , Peptídeos Cíclicos/metabolismo , Probióticos , Sequenciamento Completo do Genoma
18.
Chem Commun (Camb) ; 55(89): 13362-13365, 2019 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-31631195

RESUMO

Rule-of-five parameters and membrane permeabilities have been routinely used to guide development of orally bioavailabile drugs. Here we compare enantiomeric pairs of cyclic hexapeptides with identical rule-of-five parameters and membrane permeabilities. For each enantiomeric pair, the isomer with more l- than d-amino acids is much more orally bioavailable in rats, more metabolically stable to rat liver microsomes, and cleared more slowly in vivo.


Assuntos
Peptídeos Cíclicos/metabolismo , Peptídeos Cíclicos/farmacocinética , Administração Oral , Animais , Disponibilidade Biológica , Microssomos Hepáticos/química , Microssomos Hepáticos/metabolismo , Conformação Molecular , Peptídeos Cíclicos/administração & dosagem , Ratos , Estereoisomerismo
19.
Int J Mol Sci ; 20(19)2019 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-31590403

RESUMO

G-protein-coupled receptors associate into dimers/oligomers whose function is not well understood. One approach to investigate this issue is to challenge oligomerization by peptides replicating transmembrane domains and to study their effect on receptor functionality. The disruptor peptides are typically delivered by means of cell-penetrating vectors such as the human immunodeficiency virus (HIV) transcription trans-activation protein Tat. In this paper we report a cyclic, Tat-like peptide that significantly improves its linear analogue in targeting interreceptor sequences in the transmembrane space. The same cyclic Tat-like vector fused to a transmembrane region not involved in receptor oligomerization was totally ineffective. Besides higher efficacy, the cyclic version has enhanced proteolytic stability, as shown by trypsin digestion experiments.


Assuntos
Produtos do Gene tat/metabolismo , Peptídeos Cíclicos/metabolismo , Receptor A2A de Adenosina/metabolismo , Produtos do Gene tat/genética , Vetores Genéticos/genética , Vetores Genéticos/metabolismo , Células HEK293 , Humanos , Peptídeos Cíclicos/genética , Ligação Proteica , Multimerização Proteica , Estabilidade Proteica
20.
Appl Microbiol Biotechnol ; 103(21-22): 8647-8656, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31515599

RESUMO

In 1968, Arima et al. discovered the heptapeptide, known as surfactin, which belongs to a family of lipopeptides. Known for its ability to reduce surface tension, it also has biological activities such as antimicrobial and antiviral. Its non-ribosomal synthesis mechanism was later discovered (1991). Lipopeptides represent an important class of surfactants, which can be applied in many industrial sectors such as food, pharmaceutical, agrochemicals, detergents, and cleaning products. Currently, 75% of the surfactants used in the various industrial sectors are from the petrochemical industry. Nevertheless, there are global current demands (green chemistry concept) to replace the petrochemical products with environmentally friendly products, such as surfactants by biosurfactants. The production biosurfactants still are costly. Thus, an alternative to reduce the production costs is using agro-industrial waste as a culture medium associated with an efficient and scalable purification process. This review puts a light on the agro-industrial residues used to produce surfactin and the techniques used for its recovery.


Assuntos
Microbiologia Industrial/economia , Lipopeptídeos/economia , Lipopeptídeos/metabolismo , Peptídeos Cíclicos/economia , Peptídeos Cíclicos/metabolismo , Tensoativos/economia , Bactérias/genética , Bactérias/metabolismo , História do Século XX , História do Século XXI , Microbiologia Industrial/história , Microbiologia Industrial/métodos , Lipopeptídeos/genética , Lipopeptídeos/história , Peptídeos Cíclicos/genética , Peptídeos Cíclicos/história , Tensoativos/história , Tensoativos/metabolismo
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