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1.
Chem Commun (Camb) ; 56(19): 2917-2920, 2020 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-32037436

RESUMO

Combinatorial cyclization of hundreds to thousands of random linear peptides by structurally diverse chemical linkers offers access to large macrocyclic compound libraries. A bottleneck in the development of such libraries is the preparation of large numbers of short random linear peptides. Herein, we present a tag-based strategy that is not dependent on a throughput-limiting chromatographic purification step and thus enables parallel production of short peptides. In brief, peptides are synthesized on solid phase as conjugates with a disulfide-linked Cys-Gly-Arg-Trp tetra-peptide tag. The charged arginine residue in the tag allows for purification of the peptides by diethyl ether-precipitation and the tryptophan allows for quantification of the product by absorption measurement. Addition of a reducing agent releases the short peptides from the tag. The released sulfhydryl group in the peptide can readily be used for cyclization of the peptide library with bis-electrophilic linker reagents.


Assuntos
Dissulfetos/química , Oligopeptídeos/química , Cromatografia Líquida , Indicadores e Reagentes/química , Espectrometria de Massas , Oligopeptídeos/síntese química , Oligopeptídeos/isolamento & purificação , Biblioteca de Peptídeos
2.
Braz J Med Biol Res ; 52(11): e8441, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31721904

RESUMO

The heptapeptide Bj-PRO-7a, isolated and identified from Bothrops jararaca (Bj) venom, produces antihypertensive and other cardiovascular effects that are independent on angiotensin converting enzyme inhibition, possibly relying on cholinergic muscarinic receptors subtype 1 (M1R). However, whether Bj-PRO-7a acts upon the central nervous system and modifies behavior is yet to be determined. Therefore, the aims of this study were: i) to assess the effects of acute administration of Bj-PRO-7a upon behavior; ii) to reveal mechanisms involved in the effects of Bj-PRO-7a upon locomotion/exploration, anxiety, and depression-like behaviors. For this purpose, adult male Wistar (WT, wild type) and spontaneous hypertensive rats (SHR) received intraperitoneal injections of vehicle (0.9% NaCl), diazepam (2 mg/kg), imipramine (15 mg/kg), Bj-PRO-7a (71, 213 or 426 nmol/kg), pirenzepine (852 nmol/kg), α-methyl-DL-tyrosine (200 mg/kg), or chlorpromazine (2 mg/kg), and underwent elevated plus maze, open field, and forced swimming tests. The heptapeptide promoted anxiolytic and antidepressant-like effects and increased locomotion/exploration. These effects of Bj-PRO-7a seem to be dependent on M1R activation and dopaminergic receptors and rely on catecholaminergic pathways.


Assuntos
Ansiedade , Comportamento Animal/efeitos dos fármacos , Venenos de Crotalídeos/química , Depressão , Comportamento Exploratório/efeitos dos fármacos , Oligopeptídeos/farmacologia , Prolina/farmacologia , Animais , Comportamento Animal/fisiologia , Masculino , Oligopeptídeos/isolamento & purificação , Prolina/isolamento & purificação , Ratos , Ratos Wistar
3.
Molecules ; 24(19)2019 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-31569521

RESUMO

A novel lipid inhibition peptide Leu-Leu-Val-Val-Try-Pro-Trp-Thr-Gln-Arg (PP1) (MW 1274.53 Da) was obtained from Chlorella pyenoidose using enzymatic hydrolysis, gel filtration chromatography, and LC-MS/MS. Its lipid inhibition effects indicated that the synthetic peptide PP1 exhibits a good inhibitory effect against porcine pancreatic lipase (PL) (47.95%) at 200 µg/mL, which could be attributed to its hydrogen binding into catalytic sites of PL (Ser153, Asp177, and His 264) by docking analysis. Furthermore, in 3T3-L1 cells, the synthetic PP1 remarkedly decreased the accumulation of intracellular triacylglycerol (27.9%, 600 µg/mL), which carried a similar consequence as the positive drug simvastatin (24.1%, 10 µM). Western blot revealed that PP1 inhibited the lipid accumulation and fatty acid synthesis in 3T3-L1 adipocytes in two pathways, primarily: nonalcoholic fatty liver disease (NAFLD) pathway (C/EBPα, SREBP-1c, AMPKα) and AMPK signaling pathway (SREBP-1c, PPARγ, AMPKα). In short, these results support that PP1 can be used as a potential agent against obesity.


Assuntos
Chlorella/química , Oligopeptídeos/química , Oligopeptídeos/farmacologia , Células 3T3-L1 , Sequência de Aminoácidos , Animais , Fracionamento Químico , Relação Dose-Resposta a Droga , Hidrólise , Camundongos , Modelos Moleculares , Peso Molecular , Oligopeptídeos/isolamento & purificação , Pancrelipase/antagonistas & inibidores , Pancrelipase/química , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Conformação Proteica , Suínos
4.
Molecules ; 24(17)2019 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-31470600

RESUMO

Small signaling peptides (SSPs) are a class of short peptides playing critical roles in plant growth and development. SSPs are also involved in the phytohormone signaling pathway. However, identification of mature SSPs is still a technical challenge because of their extremely low concentrations in plant tissue and complicated interference by many other metabolites. Here, we report an optimized protocol to extract SSPs based on protoplast extraction and to analyze SSPs based on tandem mass spectrometry peptidomics. Using plant protoplasts as the material, soluble peptides were directly extracted into phosphate buffer. The interference of non-signaling peptides was significantly decreased. Moreover, we applied the protocol to identify potential SSPs in auxin treated wild type and auxin biosynthesis defective mutant yuc2yuc6. Over 100 potential SSPs showed a response to auxin in Arabidopsis thaliana.


Assuntos
Proteínas de Arabidopsis/isolamento & purificação , Arabidopsis/efeitos dos fármacos , Ácidos Indolacéticos/farmacologia , Oligopeptídeos/isolamento & purificação , Reguladores de Crescimento de Planta/farmacologia , Transdução de Sinais/efeitos dos fármacos , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/biossíntese , Proteínas de Arabidopsis/classificação , Expressão Gênica , Perfilação da Expressão Gênica , Ácidos Indolacéticos/metabolismo , Oligopeptídeos/biossíntese , Oligopeptídeos/classificação , Células Vegetais/efeitos dos fármacos , Células Vegetais/metabolismo , Reguladores de Crescimento de Planta/metabolismo , Folhas de Planta/citologia , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Plantas Geneticamente Modificadas , Proteômica/métodos , Protoplastos/efeitos dos fármacos , Protoplastos/metabolismo , Transdução de Sinais/genética
5.
Sensors (Basel) ; 19(17)2019 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-31443493

RESUMO

Quantum dots (QDs) are very attractive nanomaterials for analytical chemistry, due to high photostability, large surface area featuring numerous ways of bioconjugation with biomolecules, usually high quantum yield and long decay times. Their broad absorption spectra and narrow, sharp emission spectra of size-tunable fluorescence make them ideal tools for pattern-based sensing. However, almost always they are applied for specific sensing with zero-dimensional (0D) signal reporting (only peak heights or peak shifts are considered), without taking advantage of greater amount of information hidden in 1D signal (emission spectra), or huge amount of information hidden in 2D fluorescence maps (Excitation-Emission Matrixes, EEMs). Therefore, in this work we propose opposite strategy-non-specific interactions of QDs, which are usually avoided and regarded as their disadvantage, were exploited here for 2D fluorescence fingerprinting. Analyte-specific multivariate fluorescence response of QDs is decoded with the use of Partial Least Squares-Discriminant Analysis. Even though only one type of QDs is studied, the proposed pattern-based method enables to obtain satisfactory accuracy for all studied compounds-various neurotransmitters, amino-acids and oligopeptides. This is a proof of principle of the possibility of the identification of various bioanalytes by such fluorescence fingerprinting with the use of QDs.


Assuntos
Aminoácidos/isolamento & purificação , Técnicas Biossensoriais/métodos , Neurotransmissores/isolamento & purificação , Oligopeptídeos/isolamento & purificação , Aminoácidos/química , Neurotransmissores/química , Oligopeptídeos/química , Imagem Óptica , Pontos Quânticos/química
6.
J Antibiot (Tokyo) ; 72(10): 775-778, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31327868

RESUMO

A new N-cinnamoyl tripeptide, designated cipralphelin (1), was isolated from a cultured broth of Penicillium brevicompactum FKJ-0123 by physicochemical (PC) screening. Compound 1 was purified by silica gel and ODS column chromatography followed by preparative HPLC. The structure of 1 was determined as N-cinnamoyl-prolyl-alanyl-phenylalanine methyl ester by nuclear magnetic resonance and mass spectrometry analyses. The absolute configurations of three amino acids were determined by an advanced Marfey's method applied to the hydrolysate of 1. Compound 1 was evaluated for its cytotoxicity, anti-microbial activity, and ability to scavenge or quench reactive oxygen species (ROS) such as superoxide anion radicals, hydroxy radicals, and singlet oxygen. Compound 1 exhibited potent scavenging activity against hydroxy radicals.


Assuntos
Antioxidantes/farmacologia , Produtos Biológicos/farmacologia , Cinamatos/farmacologia , Depuradores de Radicais Livres/farmacologia , Oligopeptídeos/farmacologia , Penicillium/metabolismo , Antioxidantes/química , Antioxidantes/isolamento & purificação , Antioxidantes/metabolismo , Produtos Biológicos/química , Produtos Biológicos/isolamento & purificação , Produtos Biológicos/metabolismo , Cromatografia Líquida , Cinamatos/química , Cinamatos/isolamento & purificação , Cinamatos/metabolismo , Depuradores de Radicais Livres/química , Depuradores de Radicais Livres/isolamento & purificação , Depuradores de Radicais Livres/metabolismo , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Estrutura Molecular , Oligopeptídeos/química , Oligopeptídeos/isolamento & purificação , Oligopeptídeos/metabolismo , Penicillium/crescimento & desenvolvimento
7.
Org Biomol Chem ; 17(30): 7238-7246, 2019 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-31328741

RESUMO

The use of peptides as therapeutics has been growing due to their biocompatibility. Solid phase peptide synthesis typically used to access these peptides requires excess reagents and/or microwave irradiation to drive reactions to completion because the reaction medium is heterogeneous. Reported herein is a soluble polynorbornene support containing rink amide attached sites for synthesizing oligopeptides and conotoxins in high purity using only 1.2 to 2 equivalents of coupling reagents. The support can be isolated as a precipitate from the reaction medium by adding ether. The loading capacity of the support can be easily determined by spectroscopy and can also be tuned by varying the monomer ratio. This support is promising for accessing peptides as the methodology uses minimal reagents and by-products can be easily separated.


Assuntos
Amidas/química , Conotoxinas/isolamento & purificação , Oligopeptídeos/isolamento & purificação , Conotoxinas/síntese química , Conotoxinas/química , Estrutura Molecular , Oligopeptídeos/síntese química , Oligopeptídeos/química , Técnicas de Síntese em Fase Sólida , Solubilidade
8.
J Antibiot (Tokyo) ; 72(10): 744-751, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31243345

RESUMO

Two cyclotetrapeptides, henceforth named Provipeptides A (1) and B (2), along with five known diketopiperazines (3-7) were isolated from the liquid culture of marine Streptomyces sp. 161a recovered from a sample of sea grass Bryopsis sp. The structures of cyclotetrapeptides and diketopiperazines (DKPs) were established by 1D and 2D NMR data, MS, and by comparison with literature data. The absolute stereochemistry of compounds cyclo-(L-Pro-L-Leu-D-Pro-L-Phe) 1 and cyclo-(-Pro-Ile-Pro-Phe) 2 was established by the Marfey's method. Compound 1 showed antibacterial activity against rice phytopathogenic strains Burkholderia glumae (MIC = 1.1 mM) and Burkholderia gladioli (MIC = 0.068 mM), compound 2 was active only against B. glumae (MIC = 1.1 mM), and DKP cyclo-[L-Pro-L-Leu] 5 showed to be active against B. gladioli (MIC = 0.3 mM) and B. glumae (MIC = 2.4 mM). Compounds 1 and 2 showed 65% and 50% inhibition of Colletotrichum gloeosporioides (yam pathogen) conidia germination, respectively at a concentration of 1.1 mM.


Assuntos
Anti-Infecciosos/isolamento & purificação , Burkholderia/efeitos dos fármacos , Colletotrichum/efeitos dos fármacos , Meios de Cultura/química , Oligopeptídeos/isolamento & purificação , Peptídeos Cíclicos/isolamento & purificação , Anti-Infecciosos/farmacologia , Dioscorea/microbiologia , Testes de Sensibilidade Microbiana , Estrutura Molecular , Oligopeptídeos/farmacologia , Oryza/microbiologia , Peptídeos Cíclicos/farmacologia , Análise Espectral , Streptomyces/crescimento & desenvolvimento , Streptomyces/metabolismo
9.
Nutrients ; 11(5)2019 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-31052202

RESUMO

In this study we investigated the oligopeptide pattern in fermented cocoa beans and derived products after simulated gastrointestinal digestion. Peptides in digested cocoa samples were identified based on the mass fragmentation and on the software analysis of vicilin and 21 KDa cocoa seed protein sequences, the most abundant cocoa proteins. Quantification was carried out by liquid chromatography/electrospray ionisation mass spectrometry (LC/ESI-MS) using an internal standard. Sixty five peptides were identified in the digested samples, including three pyroglutamyl derivatives. The in vitro angiotensin-converting enzyme (ACE)-inhibitory activity of cocoa digests were tested, demonstrating a high inhibition activity, especially for digestates of cocoa beans. The peptides identified were screened for their potential ACE inhibitory activity through an in silico approach, and about 20 di-, three- and tetra-peptides actually present in our samples were predicted as active. Two of the potentially active peptides were chemically synthesized and then assessed for their inhibitory activity by using the ACE in vitro assay. These peptides demonstrated an ACE inhibitory activity, however, that was too weak to explain alone the high activity of cocoa digestates, suggesting a synergic effect of all cocoa peptides. As a whole, results showed that an average chocolate portion (30 g) ensures an amount of peptides after digestion that, assuming complete absorption, could reach almost a complete inhibition of ACE.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/metabolismo , Cacau/química , Digestão , Oligopeptídeos/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Humanos , Simulação de Acoplamento Molecular , Espectrometria de Massas por Ionização por Electrospray
10.
Mar Drugs ; 17(4)2019 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-30935056

RESUMO

A protein extract was generated from the macroalga Ulva lactuca, which was subsequently hydrolysed using the food-grade enzyme papain and angiotensin-converting Enzyme I and renin inhibitory peptides identified using a combination of enrichment strategies employing molecular weight cutoff filtration and mass spectrometry analysis. The generated hydrolysates with the most promising in vitro activity were further purified using preparative RP-HPLC and characterised. The 1 kDa hydrolysate (1 kDa-UFH), purified and collected by preparative RP-HPLC at minutes 41‒44 (Fr41‒44), displayed statistically higher ACE-I inhibitory activities ranging from 96.91% to 98.06%. A total of 48 novel peptides were identified from these four fractions by LC-MS/MS. A simulated gastrointestinal digestion of the identified peptide sequences was carried out using in silico enzyme cleavage simulation tools, resulting in 86 peptide sequences that were further assessed for their potential activity, toxicity and allergenicity using multiple predictive approaches. All the peptides obtained in this study were predicted to be non-toxic. However, 28 out of the 86 novel peptides released after the in silico gastrointestinal digestion were identified as potential allergens. The potential allergenicity of these peptides should be further explored to comply with the current labelling regulations in formulated food products containing U. lactuca protein hydrolysates.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/metabolismo , Inibidores da Enzima Conversora de Angiotensina/farmacologia , Oligopeptídeos/metabolismo , Oligopeptídeos/farmacologia , Hidrolisados de Proteína/farmacologia , Ulva/metabolismo , Alérgenos/farmacologia , Sequência de Aminoácidos , Inibidores da Enzima Conversora de Angiotensina/química , Inibidores da Enzima Conversora de Angiotensina/isolamento & purificação , Anti-Hipertensivos/farmacologia , Simulação por Computador , Humanos , Hidrólise , Oligopeptídeos/química , Oligopeptídeos/isolamento & purificação , Hidrolisados de Proteína/química , Hidrolisados de Proteína/isolamento & purificação , Alga Marinha/química , Ulva/química , Ulva/citologia
11.
J Biochem ; 166(3): 223-230, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31004484

RESUMO

Vinegar soaked black soybean is a traditional Chinese food widely used for the treatment of hypertension. While its pharmacodynamic substance was not fully unveiled. It contained abundant glutelin, thus the purpose of this study was to obtain potent antihypertensive peptides from vinegar soaked black soybean. Black soybean was soaked with vinegar and then glutelin was first catalyzed by alcalase. Ultrafiltration, ion exchange chromatography and reversed-phase high performance liquid chromatography were sequentially applied to separate and purify the angiotensin-I converting enzyme (ACE) inhibitory peptides from glutelin hydrolysates. As a result, the fraction L1-4 with the highest ACE inhibitory activity (83.41%) at the final concentration of 0.01 mg/ml was obtained and five peptides were then identified. These peptides were further optimized by virtual screening combining with in silico proteolysis. Finally, a novel tetrapeptide Phe-Gly-Ser-Phe (FGSF) was obtained. FGSF exhibited high in vitro ACE inhibitory activity (IC50 = 117.11 µM) and in vivo hypotensive effect which maximally reduced systolic blood pressure of 21.95 mmHg at 20 mg/kg body weight in spontaneously hypertensive rats. Our study demonstrated that FGSF derived from vinegar soaked black soybean might be used as a promising ingredient for pharmaceuticals against hypertension and its related diseases.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/farmacologia , Anti-Hipertensivos/farmacologia , Glutens/química , Hipertensão/tratamento farmacológico , Oligopeptídeos/farmacologia , Soja/química , Ácido Acético/química , Inibidores da Enzima Conversora de Angiotensina/química , Inibidores da Enzima Conversora de Angiotensina/isolamento & purificação , Animais , Anti-Hipertensivos/química , Anti-Hipertensivos/isolamento & purificação , Relação Dose-Resposta a Droga , Glutens/isolamento & purificação , Hipertensão/metabolismo , Masculino , Simulação de Acoplamento Molecular , Oligopeptídeos/química , Oligopeptídeos/isolamento & purificação , Peptidil Dipeptidase A/metabolismo , Ratos , Ratos Endogâmicos SHR , Relação Estrutura-Atividade
12.
Molecules ; 24(8)2019 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-31013611

RESUMO

Walnut oligopeptides (WOPs) intake is associated with the augment of the antioxidant defense system and immune system. The chief object of this study is to evaluate the radioprotective effect of walnut oligopeptides extracted from walnut seed protein against 60Coγ-irradiation induced damage in mice. Female BALB/c mice were administered WOPs through drinking water for 14 days until a single dose of whole-body 60Coγ-irradiation. The 30-day survival test was carried out in the first group (8 Gy), and the other two groups (3.5 Gy) were sacrificed at 3 days and 14 days post-irradiation. Blood and organ samples of mice in the three groups were collected, the histopathological analysis and immunohistochemistry were conducted. The number of peripheral blood leukocytes, bone marrow DNA content, inflammatory cytokines, antioxidant capacity, and intestinal permeability were measured. We found that the administration of WOPs augmented antioxidant defense system, accelerated hematopoietic recovery and showed the significant trend toward higher survival rate and less weight loss compared with non-administrated control mice. In addition, WOPs administration appeared to be important to limit IR-induced splenocyte apoptosis and inflammatory cascade as well as reduce intestine epithelial barrier dysfunction and promote epithelial integrity. These results suggest that pre and post-treatment of WOPs may help to ameliorate acute damage, which is induced by ionizing radiation in mice and accelerate its recovery.


Assuntos
Apoptose , Raios gama/efeitos adversos , Intestinos/lesões , Juglans/química , Oligopeptídeos , Proteínas de Plantas , Lesões Experimentais por Radiação , Protetores contra Radiação , Baço/metabolismo , Animais , Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Feminino , Intestinos/patologia , Camundongos , Camundongos Endogâmicos BALB C , Oligopeptídeos/química , Oligopeptídeos/isolamento & purificação , Oligopeptídeos/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/efeitos da radiação , Proteínas de Plantas/química , Proteínas de Plantas/isolamento & purificação , Proteínas de Plantas/farmacologia , Lesões Experimentais por Radiação/metabolismo , Lesões Experimentais por Radiação/patologia , Lesões Experimentais por Radiação/prevenção & controle , Protetores contra Radiação/química , Protetores contra Radiação/isolamento & purificação , Protetores contra Radiação/farmacologia , Baço/patologia
13.
J Mass Spectrom ; 54(7): 620-628, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31022326

RESUMO

Chiral molecules frequently remain undistinguishable using ion mobility mass spectrometry (IM-MS), due to insufficient differences of their collision cross sections at the available mobility resolution of the ion mobility drift tubes. The influence of the complexation with organic acids on the ion mobility separation of peptide epimers is evaluated using traveling-wave ion mobility (TWIMS). The examined epimeric tripeptides containing Arg residue with the sequence: Ac-Phe-Arg-Trp-NH2 formed stable complexes in the gas phase, and under the increased pressure in ion mobility drift tube, noncovalent associates formed with carboxylic or sulfonic monoacids and diacids with chiral variation of certain acids. Overall, the complexation with an acid leads to the improvement in stereodifferentiation among epimeric peptides, in comparison to the analysis of pure epimers. Detailed characterization of peptide epimer-acid associates obtained for dibenzoyl-D-tartaric acid by theoretical calculations and collisional dissociation studies revealed that the presence of multiple hydrogen bonding interactions between carboxylate anions and hydrogens from N-H of both the guanidinium group of arginine and the indole of tryptophan, as well as the amide backbone hydrogens in the peptide, is responsible for stability of acid-peptide complexes and for their differentiation in the ion mobility drift tube. The specificity of complex formation toward Arg was determined in terms of complex stability. Based on the reported results, we present general conclusions regarding the utility of the acid-based complexation in the separation of peptide isomers.


Assuntos
Oligopeptídeos/isolamento & purificação , Aminoácidos/química , Espectrometria de Mobilidade Iônica , Espectrometria de Massas , Modelos Moleculares , Conformação Proteica , Estereoisomerismo , Tartaratos/química
14.
Mar Drugs ; 17(2)2019 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-30781633

RESUMO

Perinereis aibuhitensis peptide (PAP) is a decapeptide (Ile-Glu-Pro-Gly-Thr-Val-Gly-Met-Met-Phe, IEPGTVGMMF) with anticancer activity that was purified from an enzymatic hydrolysate of Perinereis aibuhitensis. In the present study, the anticancer effect of PAP on H1299 cell proliferation was investigated. Our results showed that PAP promoted apoptosis and inhibited the proliferation of H1299 cells in a time- and dose-dependent manner. When the PAP concentration reached 0.92 mM, more than 95% of treated cells died after 72 h of treatment. Changes in cell morphology were further analyzed using an inverted microscope and AO/EB staining and flow cytometry was adopted for detecting apoptosis and cell cycle phase. The results showed that the early and late apoptosis rates of H1299 cells increased significantly after treatment with PAP and the total apoptosis rate was significantly higher than that of the control group. Moreover, after treatment with PAP, the number of cells in the S phase of cells was significantly reduced and the ability for the cells to proliferate was also reduced. H1299 cells were arrested in the G2/M phase and cell cycle progression was inhibited. Furthermore, the results of western blotting showed that nm23-H1 and vascular endothelial growth factor (VEGF) protein levels decreased in a dose-dependent manner, while the pro-apoptotic protein and anti-apoptotic protein ratios and the level of apoptosis-related caspase protein increased in a dose-dependent manner. In conclusion, our results indicated that PAP, as a natural marine bioactive substance, inhibited proliferation and induced apoptosis of human lung cancer H1299 cells. PAP is likely to be exploited as the functional food or adjuvant that may be used for prevention or treatment of human non-small cell lung cancer in the future.


Assuntos
Antineoplásicos/farmacologia , Oligopeptídeos/farmacologia , Poliquetos/química , Sequência de Aminoácidos , Animais , Antineoplásicos/isolamento & purificação , Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose/metabolismo , Caspases/metabolismo , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Metástase Neoplásica/prevenção & controle , Oligopeptídeos/isolamento & purificação , Fator A de Crescimento do Endotélio Vascular/biossíntese
15.
Food Res Int ; 116: 707-716, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30716998

RESUMO

To elucidate the sequence, origin and structure-activity relationship of antioxidant peptides from sesame protein, sesame protein was hydrolysed by a dual-enzyme system comprised alcalase and trypsin, then this hydrolysate was fractionated by ultrafiltration and preparative HPLC. Subsequently, peptides in the high antioxidant activity fraction were identified by nano liquid chromatography-electrospray ionization-tandem mass spectrometry (Nano-LC-ESI-MS/MS), finally the structure-activity relationship of antioxidant peptide with the strongest activity in the sesame peptides was illustrated by comparative molecular field analysis (CoMFA). The results showed that seven novel antioxidant peptides were discovered, their sequences were as follows, RDRHQKIG, TDRHQKLR, MNDRVNQGE, RENIDKPSRA, SYPTECRMR, GGVPRSGEQEQQ and AGEQGFEYVTFR. The SYPTECRMR was the hydrolysate of 2S albumin, the others derived from 11S globulin. The SYPTECRMR whose IC50 Values of DPPH and ABTS were 0.105 mg/mL and 0.004 mg/mL respectively exhibited the highest antioxidant activity among the seven sesame peptides. The active site of SYPTECRMR tended to locate on Cys6 and Met8. A positive correlation between Cys6, Met8, the bulky C-terminal amino acid residue (Arg9), the negative charged group around sulphur-containing amino acids and the antioxidant activity of SYPTECRMR was observed from the CoMFA model. The results presented herein suggested that sesame protein hydrolysates have potential applications in functional food due to their high antioxidant activity, the CoMFA model could provide insight into the structure-activity relationship of antioxidant peptide, which is useful to screen, identify and design the novel antioxidant peptide.


Assuntos
Antioxidantes/farmacologia , Oligopeptídeos/farmacologia , Hidrolisados de Proteína/química , Sementes/química , Sesamum/química , Sequência de Aminoácidos , Antioxidantes/isolamento & purificação , Benzotiazóis/química , Compostos de Bifenilo/química , Modelos Moleculares , Oligopeptídeos/isolamento & purificação , Picratos/química , Relação Quantitativa Estrutura-Atividade , Subtilisinas/química , Ácidos Sulfônicos/química , Tripsina/química
16.
J Agric Food Chem ; 67(5): 1437-1442, 2019 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-30609899

RESUMO

We recently identified a novel, potent antihypertensive peptide, Leu-Arg-Ala (LRA; minimum effective dose = 0.25 mg/kg), from rice bran protein. In this study, we found that LRA potently relaxed mesenteric arteries isolated from spontaneously hypertensive rats (SHRs) (EC50 = 0.1 µM). In contrast, the vasorelaxant activity of each amino acid that constitutes the LRA tripeptide was remarkably attenuated. The LRA-induced vasorelaxant activity was inhibited by N(G)-nitro-l-arginine methyl ester (L-NAME; NO synthase [NOS] inhibitor) but not by an antagonist of bradykinin B2 and Mas receptors or by a phosphoinositide 3-kinase inhibitor. The antihypertensive effect induced after the oral administration of LRA was inhibited by L-NAME. LRA also induced the phosphorylation of endothelial NOS in human umbilical vein endothelial cells. Taken together, LRA may exhibit antihypertensive effects via NO-mediated vasorelaxation. LRA is the first example of a NO-dependent vasorelaxant peptide identified from rice bran protein.


Assuntos
Anti-Hipertensivos/administração & dosagem , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Óxido Nítrico/metabolismo , Oligopeptídeos/administração & dosagem , Oryza/química , Extratos Vegetais/administração & dosagem , Vasodilatadores/administração & dosagem , Animais , Anti-Hipertensivos/isolamento & purificação , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Hipertensão/metabolismo , Hipertensão/fisiopatologia , Masculino , Oligopeptídeos/isolamento & purificação , Extratos Vegetais/isolamento & purificação , Ratos , Ratos Endogâmicos SHR , Sementes/química , Vasodilatação/efeitos dos fármacos , Vasodilatadores/isolamento & purificação
17.
J Zhejiang Univ Sci B ; 20(1): 59-70, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30614230

RESUMO

Globally, peptide-based anticancer therapies have drawn much attention. Marine organisms are a reservoir of anticancer peptides that await discovery. In this study, we aimed to identify cytotoxic oligopeptides from Sarcophyton glaucum. Peptides were purified from among the S. glaucum hydrolysates produced by alcalase, chymotrypsin, papain, and trypsin, guided by a methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay on the human cervical cancer (HeLa) cell line for cytotoxicity evaluation. Purification techniques adopted were membrane ultrafiltration, gel filtration chromatography, solid phase extraction (SPE), and reversed-phase high-performance liquid chromatography (RP-HPLC). Purified peptides were identified by de novo peptide sequencing. From papain hydrolysate, three peptide sequences were identified: AGAPGG, AERQ, and RDTQ (428.45, 502.53, and 518.53 Da, respectively). Peptides synthesized from these sequences exhibited cytotoxicity on HeLa cells with median effect concentration (EC50) values of 8.6, 4.9, and 5.6 mmol/L, respectively, up to 5.8-fold stronger than the anticancer drug 5-fluorouracil. When tested at their respective EC50, AGAPGG, AERQ, and RDTQ showed only 16%, 25%, and 11% cytotoxicity to non-cancerous Hek293 cells, respectively. In conclusion, AERQ, AGAPGG, and RDTQ are promising candidates for future development as peptide-based anticancer drugs.


Assuntos
Antozoários/química , Citotoxinas/isolamento & purificação , Toxinas Marinhas/isolamento & purificação , Oligopeptídeos/isolamento & purificação , Sequência de Aminoácidos , Animais , Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Cromatografia em Gel , Cromatografia Líquida de Alta Pressão , Cromatografia de Fase Reversa , Citotoxinas/farmacologia , Descoberta de Drogas , Células HEK293 , Células HeLa , Humanos , Hidrólise , Toxinas Marinhas/farmacologia , Oligopeptídeos/farmacologia , Extração em Fase Sólida , Espectrometria de Massas em Tandem
18.
Food Chem ; 278: 674-682, 2019 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-30583429

RESUMO

Six novel peptides were separated from peanut protein isolate hydrolysate (PPIH) using ethanol precipitation and gel chromatography, and identified as DQR, NNP, EGF, EDG, TESSSE and RGENESEEEGAIVT by UPLC-ESI-QTOF-MS/MS. On the basis of sensory results, all peptides were perceived umami with threshold values from 0.39 to 1.11 mM and had umami-enhancing abilities simultaneously with threshold values from 0.33 to 0.82 mM. RGENESEEEGAIVT was the first discovered tetradecapeptide with umami and umami-enhancing ability. The dose-response test revealed that umami-enhancing activities of identified peptides were different: TESSSE and RGENESEEEGAIVT imparted better umami intensity when equimolar monosodium glutamate (MSG) was added into 0.5 g/L MSG solution. Taste profile analyses of complex mixtures with/without synthetic peptides were determined by both electronic tongue and human panellists, suggesting that umami peptides influence multiple tastes and electronic tongue has the potential to replace sensory test to distinguish taste attributes of foods rich in peptides.


Assuntos
Arachis/metabolismo , Oligopeptídeos/química , Proteínas de Plantas/metabolismo , Paladar/fisiologia , Sequência de Aminoácidos , Precipitação Química , Cromatografia Líquida de Alta Pressão , Nariz Eletrônico , Humanos , Oligopeptídeos/isolamento & purificação , Hidrolisados de Proteína/metabolismo , Glutamato de Sódio/química , Espectrometria de Massas por Ionização por Electrospray
19.
Molecules ; 24(1)2018 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-30583565

RESUMO

Walnut (Juglans regia L.) is unique for its extensive biological activities and pharmaceutical properties. There are few studies on walnut oligopeptides (WOPs), which are small molecule peptides extracted from walnuts. This study aimed to evaluate the anti-fatigue effects of WOPs on ICR mice and explore the possible underlying mechanism. Mice were randomly divided into four experimental sets and each set of mice were then randomly divided into four groups. The vehicle group was administered distilled water, and the three WOP intervention groups were orally administered WOP solution at a dose of 110, 220, and 440 mg/kg of body weight, respectively. After 30 days of WOP intervention, the anti-fatigue activity of WOPs were evaluated using the weight-loaded swimming test and by measuring the change of biochemical parameters, glycogen storage and energy metabolism enzymes, anti-oxidative capacity and mitochondrial function. It was observed that WOPs could significantly prolong the swimming time, decrease the accumulation of lactate dehydrogenase (LDH), creatine kinase (CK), blood urea nitrogen (BUN) and blood lactic acid (BLA), and increased the glycogen storage of liver and gastrocnemius muscle. WOPs also markedly inhibited fatigue induced oxidative stress by increasing the activity of superoxide dismutase (SOD), glutathione peroxidase (GPX) and decreasing the content malondialdehyde (MDA). Notably, WOPs improved the activity of pyruvate kinase (PK), succinate dehydrogenase (SDH), Na+-K+-ATPase, and enhanced the mRNA expression of mitochondrial biogenesis factors and mitochondrial DNA content in skeletal muscles of mice. These results suggest that WOPs have beneficial anti-fatigue effects, which may be attributed to their positive effects on increasing glycogen storage, improving energy metabolism, inhibiting oxidative stress, enhancing mitochondrial function in skeletal muscle, and ameliorating the cell damage and the muscular injury.


Assuntos
Fadiga/tratamento farmacológico , Juglans/química , Oligopeptídeos/química , Oligopeptídeos/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Animais , Biomarcadores , Glicemia/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , DNA Mitocondrial , Fadiga/metabolismo , Dosagem de Genes , Camundongos , Músculo Esquelético/efeitos dos fármacos , Músculo Esquelético/metabolismo , Oligopeptídeos/isolamento & purificação , Estresse Oxidativo/efeitos dos fármacos , Extratos Vegetais/isolamento & purificação , Natação
20.
Food Chem ; 266: 420-426, 2018 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-30381207

RESUMO

The objective of this study was to investigate the antioxidant activity and the homology of peptides extracted from dry-cured Xuanwei and Jinhua ham. The antioxidant activity of crude peptides was assessed by ORAC and ABTS assays and the scavenging effects on DPPH and O2- free radicals. LC-ESI-Q-TOF-MS/MS was used to analyze the peptide composition. Based on the identified peptides, homologous proteins were matched by the Peaks software. Overall, 243 and 213 peptides were identified with their parent proteins in Xuanwei and Jinhua dry-cured hams. Based on the ORAC and TEAC values, XHP showed higher antioxidant ability than JHP (P < 0.05). After further purification by G-15 chromatography, the results indicate that the oligopeptides with less than 1000 Da had greater antioxidant activity than the other two fractions. Homology-based proteomics showed that the majority of peptides originated from myosin which accounted for 26% in XHP and 32% in JHP respectively.


Assuntos
Antioxidantes/química , Produtos da Carne/análise , Peptídeos/química , Proteômica , Sequência de Aminoácidos , Animais , Antioxidantes/análise , Cromatografia Líquida de Alta Pressão , Peso Molecular , Oligopeptídeos/análise , Oligopeptídeos/química , Oligopeptídeos/isolamento & purificação , Peptídeos/análise , Peptídeos/isolamento & purificação , Suínos , Espectrometria de Massas em Tandem
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