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1.
Int J Mol Sci ; 24(11)2023 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-37298504

RESUMO

Transient receptor potential vanilloid 1 (TRPV1), a non-selective cation channel, can be directly activated by oxidants through cysteine modification. However, the patterns of cysteine modification are unclear. Structural analysis showed that the free sulfhydryl groups of residue pairs C387 and C391 were potentially oxidized to form a disulfide bond, which is expected to be closely related to the redox sensing of TRPV1. To investigate if and how the redox states of C387 and C391 activate TRPV1, homology modeling and accelerated molecular dynamic simulations were performed. The simulation revealed the conformational transfer during the opening or closing of the channel. The formation of a disulfide bond between C387 and C391 leads to the motion of pre-S1, which further propagates conformational change to TRP, S6, and the pore helix from near to far. Residues D389, K426, E685-Q691, T642, and T671 contribute to the hydrogen bond transfer and play essential roles in the opening of the channel. The reduced TRPV1 was inactivated mainly by stabilizing the closed conformation. Our study elucidated the redox state of C387-C391 mediated long-range allostery of TRPV1, which provided new insights into the activation mechanism of TRPV1 and is crucial for making significant advances in the treatment of human diseases.


Assuntos
Cisteína , Simulação de Dinâmica Molecular , Humanos , Cisteína/química , Oxirredução , Domínios Proteicos , Dissulfetos , Canais de Cátion TRPV/metabolismo
2.
Bioorg Med Chem ; 28(1): 115186, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31759826

RESUMO

The co-crystal structure of Compound 6b with tubulin was prepared and solved for indicating the binding mode and for further optimization. Based on the co-crystal structures of tubulin with plinabulin and Compound 6b, a total of 27 novel A/B/C-rings plinabulin derivatives were designed and synthesized. Their biological activities were evaluated against human lung cancer NCI-H460 cell line. The optimum phenoxy-diketopiperazine-type Compound 6o exhibited high potent cytotoxicity (IC50 = 4.0 nM) through SAR study of three series of derivatives, which was more potent than plinabulin (IC50 = 26.2 nM) and similar to Compound 6b (IC50 = 3.8 nM) against human lung cancer NCI-H460 cell line. Subsequently, the Compound 6o was evaluated against other four human cancer cell lines. Both tubulin polymerization assay and immunofluorescence assay showed that Compound 6o could inhibit microtubule polymerization efficiently. Furthermore, theoretical calculation of the physical properties and molecular docking were elucidated for these plinabulin derivatives. The binding mode of Compound 6o was similar to Compound 6b based on the result of molecular docking. The theoretical calculated LogPo/w and PCaco of Compound 6o were better than Compound 6b, which could enhance its cytostatic activity. Therefore, Compound 6o might be developed as a novel potent anti-microtubule agent.


Assuntos
Antineoplásicos/farmacologia , Dicetopiperazinas/farmacologia , Desenvolvimento de Medicamentos , Antineoplásicos/síntese química , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cristalografia por Raios X , Dicetopiperazinas/síntese química , Dicetopiperazinas/química , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Modelos Moleculares , Estrutura Molecular , Relação Estrutura-Atividade , Células Tumorais Cultivadas
3.
Mar Drugs ; 17(5)2019 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-31035725

RESUMO

Melanoma is one of the most malignant and aggressive types of cancer worldwide. Fibroblast growth factor 2 (FGF2) is one of the critical regulators of melanoma angiogenesis and metastasis; thus, it might be an effective anti-cancer strategy to explore FGF2-targeting drug candidates from existing drugs. In this study, we evaluate the effect of the marine drug propylene glycol alginate sodium sulfate (PSS) on FGF2-mediated angiogenesis and invasion. The data shows that FGF2 selectively bound to PSS with high affinity. PSS inhibited FGF2-mediated angiogenesis in a rat aortic ring model and suppressed FGF2-mediated invasion, but not the migration of murine melanoma B16-F10 cells. The further mechanism study indicates that PSS decreased the expression of activated matrix metalloproteinase 2 (MMP-2) and matrix metalloproteinase 9 (MMP-9), and also suppressed their activity. In addition, PSS was found to decrease the level of Vimentin in B16-F10 cells, which is known to participate in the epithelial-mesenchymal transition. Notably, PSS did not elicit any changes in cancer cell viability. Based on the results above, we conclude that PSS might be a potential drug to regulate the tumor microenvironment in order to facilitate the recovery of melanoma patients.


Assuntos
Alginatos/farmacologia , Fator 2 de Crescimento de Fibroblastos/metabolismo , Melanoma Experimental/tratamento farmacológico , Neovascularização Patológica/tratamento farmacológico , Neoplasias Cutâneas/tratamento farmacológico , Alginatos/uso terapêutico , Animais , Aorta/efeitos dos fármacos , Organismos Aquáticos/química , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Embrião de Galinha , Membrana Corioalantoide , Avaliação Pré-Clínica de Medicamentos , Transição Epitelial-Mesenquimal , Humanos , Laminaria/química , Melanoma Experimental/irrigação sanguínea , Melanoma Experimental/patologia , Camundongos , Invasividade Neoplásica/patologia , Invasividade Neoplásica/prevenção & controle , Neovascularização Patológica/patologia , Neovascularização Fisiológica/efeitos dos fármacos , Técnicas de Cultura de Órgãos , Ratos , Neoplasias Cutâneas/irrigação sanguínea , Neoplasias Cutâneas/patologia , Microambiente Tumoral/efeitos dos fármacos
4.
Bioorg Med Chem ; 26(8): 2061-2072, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29571653

RESUMO

Based on the co-crystal structures of tubulin with plinabulin and Compound 1 (a derivative of plinabulin), a total of 18 novel plinabulin derivatives were designed and synthesized. Their biological activities were evaluated against human pancreatic cancer BxPC-3 cell lines. Two novel Compounds 13d and 13e exhibited potent activities with IC50 at 1.56 and 1.72 nM, respectively. The tubulin polymerization assay indicated that these derivatives could inhibit microtubule polymerization. Furthermore, the interaction between tubulin and these compounds were elucidated by molecular docking. The binding modes of Compounds 13d and 13e were similar to the co-crystal structure of Compound 1. H-π interaction was observed between the aromatic hydrogen of thiophene moiety with Phe20, which could enhance their binding affinities.


Assuntos
Antineoplásicos/síntese química , Dicetopiperazinas/química , Desenho de Fármacos , Moduladores de Tubulina/síntese química , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Sítios de Ligação , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cristalografia por Raios X , Dicetopiperazinas/metabolismo , Dicetopiperazinas/farmacologia , Humanos , Simulação de Acoplamento Molecular , Neoplasias Pancreáticas/patologia , Estrutura Terciária de Proteína , Solubilidade , Relação Estrutura-Atividade , Tubulina (Proteína)/química , Tubulina (Proteína)/metabolismo , Moduladores de Tubulina/metabolismo , Moduladores de Tubulina/farmacologia
5.
Ann Pharmacother ; 50(9): 725-33, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27307415

RESUMO

BACKGROUND: Statins have proven cardioprotective effects, but higher doses are accompanied by various concerns and may not lead to superior clinical outcomes in Chinese/Asian populations. OBJECTIVE: We designed a trial to test the efficacy of high-intensity statin therapy for the reduction of periprocedural myocardial infarction (MI) and 1-year major adverse cardiovascular events (MACEs, including cardiovascular death, spontaneous MI, unplanned revascularization) in an Asian population. METHODS: A total of 798 Chinese patients with stable angina or acute coronary syndrome (ACS) were randomized to high-intensity atorvastatin (80 mg/d before percutaneous coronary intervention [PCI] and 40 mg/d thereafter for 1 year, n = 400) or moderate-intensity atorvastatin (20 mg/d for 1 year, n = 398). The primary end point was 1-year incidence of MACEs. RESULT: In patients with stable angina, 1-year MACE rates were not significantly different between moderate- and high-intensity groups (7.6% vs 5.7%, P = 0.53). In contrast, in patients with ACS, the 1-year MACE rate was significantly higher in the moderate- than in the high-intensity atorvastatin group (16.8% vs 10.1%, P = 0.021; adjusted hazard ratio = 1.71, 95% CI = 1.08 to 2.77, P = 0.021). CONCLUSIONS: Whereas stable angina patients derive similar benefit from moderate- and high-intensity atorvastatin therapy over the duration of 1 year after PCI, high-intensity statin therapy is superior in ACS patients.


Assuntos
Atorvastatina/administração & dosagem , Atorvastatina/uso terapêutico , Inibidores de Hidroximetilglutaril-CoA Redutases/administração & dosagem , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Infarto do Miocárdio/prevenção & controle , Intervenção Coronária Percutânea/métodos , Síndrome Coronariana Aguda/sangue , Síndrome Coronariana Aguda/cirurgia , Idoso , Angina Estável/sangue , Angina Estável/cirurgia , China , Interpretação Estatística de Dados , Relação Dose-Resposta a Droga , Feminino , Humanos , Incidência , Lipídeos/sangue , Testes de Função Hepática , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/sangue , Infarto do Miocárdio/epidemiologia , Intervenção Coronária Percutânea/efeitos adversos , Resultado do Tratamento , Troponina I/sangue
6.
Chem Biol Drug Des ; 102(3): 444-456, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-36509697

RESUMO

The natural products plinabulin, docetaxel, and vinblastine are microtubule targeting agents (MTAs). They have been used alone or in combination in cancer treatment. However, the exact nature of their effects on microtubule (MT) polymerization dynamics is poorly understood. To elucidate the longitudinal conformational and energetic changes during MT dynamics, a total of 140 ns molecular dynamic simulations combined with binding free energy calculations were performed on seven tubulin models. The results indicated that the drugs disrupted MT polymerization by altering both MT conformation and binding free energy of the neighboring tubulin subunits. The combination of plinabulin and docetaxel destabilized MT polymerization due to bending MT and weakening the polarity of tubulin polymerization. The new combination of docetaxel and vinblastine synergistically enhanced MT depolymerization and bending, while plinabulin and vinblastine had no synergistic inhibitory effects. The results were verified by the tubulin assembly assay. Our study obtained a comprehensive understanding of the action mechanisms of three natural drugs and their combinations on MT dynamic, provided theoretical guidance for new MTA combinations, and would promote the optimal use of MTA and contribute to developing new MTAs as anticancer agents.


Assuntos
Antineoplásicos , Moduladores de Tubulina , Tubulina (Proteína) , Antineoplásicos/farmacologia , Docetaxel/farmacologia , Docetaxel/metabolismo , Microtúbulos , Tubulina (Proteína)/metabolismo , Vimblastina/farmacologia , Vimblastina/análise , Vimblastina/metabolismo , Moduladores de Tubulina/química , Moduladores de Tubulina/farmacologia
7.
Acta Pharm Sin B ; 13(7): 2963-2975, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37521868

RESUMO

Insulin-like growth factor-1 receptor (IGF-1R) has been made an attractive anticancer target due to its overexpression in cancers. However, targeting it has often produced the disappointing results as the role played by cross talk with numerous downstream signalings. Here, we report a disobliging IGF-1R signaling which promotes growth of cancer through triggering the E3 ubiquitin ligase MEX3A-mediated degradation of RIG-I. The active ß-arrestin-2 scaffolds this disobliging signaling to talk with MEX3A. In response to ligands, IGF-1Rß activated the basal ßarr2 into its active state by phosphorylating the interdomain domain on Tyr64 and Tyr250, opening the middle loop (Leu130‒Cys141) to the RING domain of MEX3A through the conformational changes of ßarr2. The models of ßarr2/IGF-1Rß and ßarr2/MEX3A could interpret the mechanism of the activated-IGF-1R in triggering degradation of RIG-I. The assay of the mutants ßarr2Y64A and ßarr2Y250A further confirmed the role of these two Tyr residues of the interlobe in mediating the talk between IGF-1Rß and the RING domain of MEX3A. The truncated-ßarr2 and the peptide ATQAIRIF, which mimicked the RING domain of MEX3A could prevent the formation of ßarr2/IGF-1Rß and ßarr2/MEX3A complexes, thus blocking the IGF-1R-triggered RIG-I degradation. Degradation of RIG-I resulted in the suppression of the IFN-I-associated immune cells in the TME due to the blockade of the RIG-I-MAVS-IFN-I pathway. Poly(I:C) could reverse anti-PD-L1 insensitivity by recovery of RIG-I. In summary, we revealed a disobliging IGF-1R signaling by which IGF-1Rß promoted cancer growth through triggering the MEX3A-mediated degradation of RIG-I.

8.
Environ Pollut ; 333: 122012, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37307862

RESUMO

For the purpose of screening high-efficiency and low-risk green pesticides, a systematic study on fungicide penthiopyrad was conducted at the enantiomeric level. The bioactivity of S-(+)-penthiopyrad (median effective concentration (EC50), 0.035 mg/L) against Rhizoctonia solani was 988 times higher than R-(-)-penthiopyrad (EC50, 34.6 mg/L), which would reduce 75% usage of rac-penthiopyrad under the same efficacy. Furthermore, their antagonistic interaction (toxic unit (TUrac), 2.07) indicated the existence of R-(-)-penthiopyrad would reduce the fungicidal activity of S-(+)-penthiopyrad. AlphaFold2 modeling and molecular docking illustrated that S-(+)-penthiopyrad had the higher binding ability with the target protein than R-(-)-penthiopyrad, showing higher bioactivity. For model organism Danio rerio, S-(+)-penthiopyrad (median lethal concentrations (LC50), 3.02 mg/L) and R-(-)-penthiopyrad (LC50, 4.89 mg/L) were both less toxic than rac-penthiopyrad (LC50, 2.73 mg/L), and the existence of R-(-)-penthiopyrad could synergistically enhance the toxicity of S-(+)-penthiopyrad (TUrac, 0.73), using S-(+)-penthiopyrad would reduce at least 23% toxicity to fish. The enantioselective dissipation and residues of rac-penthiopyrad were tested in three kinds of fruits, and their dissipation half-lives ranged from 1.91 to 23.7 d. S-(+)-penthiopyrad was dissipated preferentially in grapes, which was R-(-)-penthiopyrad in pears. On the 60th d, the residue concentrations of rac-penthiopyrad in grapes were still higher than its maximum residue limit (MRL), but the initial concentrations were lower than their MRL values in watermelons and pears. Thus, more tests in different cultivars of grapes and planting environments should be encouraged. Based on the acute and chronic dietary intake risk assessments, the risks in the three fruits were all acceptable. In conclusion, S-(+)-penthiopyrad is a high-efficiency and low-risk alternative to rac-penthiopyrad.


Assuntos
Fungicidas Industriais , Praguicidas , Animais , Estereoisomerismo , Simulação de Acoplamento Molecular , Fungicidas Industriais/toxicidade , Fungicidas Industriais/química , Comportamento de Redução do Risco
9.
Int J Mol Sci ; 13(5): 6138-6155, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22754355

RESUMO

Androgen receptor antagonists have been proved to be effective anti-prostate cancer agents. 3D-QSAR and Molecular docking methods were performed on curcumin derivatives as androgen receptor antagonists. The bioactive conformation was explored by docking the potent compound 29 into the binding site of AR. The constructed Comparative Molecular Field Analysis (CoMFA) and Comparative Similarity Indices Analysis (CoMSIA) models produced statistically significant results with the cross-validated correlation coefficients q(2) of 0.658 and 0.567, non-cross-validated correlation coefficients r(2) of 0.988 and 0.978, and predicted correction coefficients r(2) (pred) of 0.715 and 0.793, respectively. These results ensure the CoMFA and CoMSIA models as a tool to guide the design of novel potent AR antagonists. A set of 30 new analogs were proposed by utilizing the results revealed in the present study, and were predicted with potential activities in the developed models.


Assuntos
Antagonistas de Receptores de Andrógenos/química , Antagonistas de Receptores de Andrógenos/farmacologia , Antineoplásicos/química , Antineoplásicos/farmacologia , Curcumina/análogos & derivados , Curcumina/farmacologia , Sítios de Ligação , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Desenho de Fármacos , Humanos , Masculino , Simulação de Acoplamento Molecular , Neoplasias da Próstata/patologia , Relação Quantitativa Estrutura-Atividade
10.
Toxins (Basel) ; 14(11)2022 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-36422985

RESUMO

Peptide toxins generally have extreme pharmacological activities and provide a rich source for the discovery of drug leads. However, determining the optimal activity of a new peptide can be a long and expensive process. In this study, peptide toxins were retrieved from Uniprot; three positive-unlabeled (PU) learning schemes, adaptive basis classifier, two-step method, and PU bagging were adopted to develop models for predicting the biological function of new peptide toxins. All three schemes were embedded with 14 machine learning classifiers. The prediction results of the adaptive base classifier and the two-step method were highly consistent. The models with top comprehensive performances were further optimized by feature selection and hyperparameter tuning, and the models were validated by making predictions for 61 three-finger toxins or the external HemoPI dataset. Biological functions that can be identified by these models include cardiotoxicity, vasoactivity, lipid binding, hemolysis, neurotoxicity, postsynaptic neurotoxicity, hypotension, and cytolysis, with relatively weak predictions for hemostasis and presynaptic neurotoxicity. These models are discovery-prediction tools for active peptide toxins and are expected to accelerate the development of peptide toxins as drugs.


Assuntos
Toxinas Biológicas , Humanos , Peptídeos/toxicidade , Hemólise , Cardiotoxicidade , Morte Celular
11.
J Geriatr Cardiol ; 19(6): 435-444, 2022 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-35845162

RESUMO

BACKGROUND: Remote ischemic conditioning (RIC) is used to protect against myocardial injury. However, there is no adequate evidence for comprehensive RIC in elderly patients with ST-segment elevation myocardial infarction (STEMI). This study aimed to test whether comprehensive RIC, started pre-primary percutaneous coronary intervention (PPCI) and repeated daily on 1-30 days post-PPCI, can improve myocardial salvage index (SI), left ventricular ejection fraction (LVEF), Kansas City Cardiomyopathy Questionnaire Clinical Summary Score (KCCQ-CSS) and 6-min walk test distance (6MWD) in elderly patients with acute STEMI during 12 months follow-up. METHODS: 328 consenting elderly patients were randomized to receive standard PPCI plus comprehensive RIC (the treatment group) or standard PPCI (the control group). SI at 5-7 days after PPCI, LVEF, left ventricular end-diastolic volume index (LVEDVI), left ventricular end-systolic volume index (LVESVI), KCCQ-CSS, 6MWD and adverse events rates were measured and assessed. RESULTS: SI was significantly higher in the treatment group [interquartile range (IQR): 0.38-0.66, P = 0.037]. There were no significant differences in major adverse events at 12 months. Although the differences of LVEDVI, LVESVI and LVEF between the treatment group and the control group did not reach statistical significance at 6 months and 12 months, LVEF tended to be higher, LVEDVI tended to be lower in the treatment group. The KCCQ-CSS was significantly higher in the treatment group at 1 month (IQR: 46.5-87, P = 0.001) and 12 months (IQR: 55-93, P = 0.008). There was significant difference in 6MWD between the treatment group and the control group (IQR: 258-360 vs. IQR: 250-345, P = 0.002) at 1 month and (IQR: 360-445 vs. IQR: 345-432, P = 0.035) at 12 months. A modest correlation was found between SI and LVEF (r = 0.452, P < 0.01), KCCQ-CSS ( r = 0.440, P < 0.01) and 6MWD ( r = 0.384, P < 0.01) respectively at 12 months. CONCLUSIONS: The comprehensive RIC can improve SI, KCCQ-CSS and 6MWD. It may be an adjunctive therapy to PPCI in elderly patients with STEMI.

12.
Bioorg Med Chem Lett ; 21(4): 1118-21, 2011 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-21269829

RESUMO

Ero1p, using molecular oxygen as its preferred terminal electron acceptor, promotes disulfide bond formation by interaction with protein disulfide isomerase. Dysfunction of Ero1p leads to strong activation of the unfolded protein response and marked loss of cell viability. However, modest attenuation of Ero1p improves the fitness of yeast challenged with high levels of protein misfolding in their endoplasmic reticulum stress. Partial inhibition of Ero1p is hence of great significance. In the present paper, a docking-based virtual screening method was performed to identify inhibitors of Ero1p and 12 hits were successfully obtained from 81 purchased compounds with micromolar inhibition against Ero1p. Particularly, six of the hits demonstrated remarkable potency with IC(50)<30µM and held the prospect of becoming lead compounds. Then the interaction modes were analyzed for further lead optimization.


Assuntos
Glicoproteínas/antagonistas & inibidores , Oxirredutases atuantes sobre Doadores de Grupo Enxofre/antagonistas & inibidores , Proteínas de Saccharomyces cerevisiae/antagonistas & inibidores , Bibliotecas de Moléculas Pequenas/química , Sítios de Ligação , Simulação por Computador , Bases de Dados de Proteínas , Flavina-Adenina Dinucleotídeo/química , Glicoproteínas/metabolismo , Humanos , Glicoproteínas de Membrana/antagonistas & inibidores , Glicoproteínas de Membrana/metabolismo , Oxirredutases/antagonistas & inibidores , Oxirredutases/metabolismo , Oxirredutases atuantes sobre Doadores de Grupo Enxofre/metabolismo , Saccharomyces cerevisiae/enzimologia , Proteínas de Saccharomyces cerevisiae/metabolismo , Bibliotecas de Moléculas Pequenas/farmacologia
13.
ACS Chem Neurosci ; 12(24): 4535-4545, 2021 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-34738810

RESUMO

Nicotinic acetylcholine receptors (nAChRs) are pentameric ligand-gated ion channels that are abundantly expressed in the central and peripheral nervous systems, playing an important role in mediating neurotransmitter release and inter-synaptic signaling. Dysfunctional nAChRs are associated with neurological disorders, and studying the structure and function of nAChRs is essential for development of drugs or strategies for treatment of related diseases. α-Conotoxins are selective antagonists of the nAChR and are an important class of drug leads. So far, the antagonistic mechanism of α-conotoxins toward the nAChRs is still unclear. In this study, we built an α3ß2 nAChR homology model and investigated its conformational transition mechanism upon binding with a highly potent inhibitor, α-conotoxin BuIA, through µs molecular dynamic simulations and site-directed mutagenesis studies. The results suggested that the α3ß2 nAChR underwent global conformational transitions and was stabilized into a closed state with three hydrophobic gates present in the transmembrane domain by BuIA. Finally, the probable antagonistic mechanism of BuIA was proposed. Overall, the closed-state model of the α3ß2 nAChR bound with BuIA is not only essential for understanding the antagonistic mechanism of α-conotoxins but also particularly valuable for development of therapeutic inhibitors in future.


Assuntos
Conotoxinas , Receptores Nicotínicos , Acetilcolina , Conotoxinas/farmacologia , Humanos , Conformação Molecular , Mutagênese Sítio-Dirigida , Antagonistas Nicotínicos/farmacologia , Receptores Nicotínicos/metabolismo
14.
Pharmacol Ther ; 222: 107792, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33309557

RESUMO

α-Conotoxins are disulfide-rich and well-structured peptides, most of which can block nicotinic acetylcholine receptors (nAChRs) with exquisite selectivity and potency. There are various nAChR subtypes, of which the α9α10 nAChR functions as a heteromeric ionotropic receptor in the mammalian cochlea and mediates postsynaptic transmission from the medial olivocochlear. The α9α10 nAChR subtype has also been proposed as a target for the treatment of neuropathic pain and the suppression of breast cancer cell proliferation. Therefore, α-conotoxins targeting the α9α10 nAChR are potentially useful in the development of specific therapeutic drugs and pharmacological tools. Despite dissimilarities in their amino acid sequence and structures, these conopeptides are potent antagonists of the α9α10 nAChR subtype. Consequently, the activity and stability of these peptides have been subjected to chemical modifications. The resulting synthetic analogues have not only functioned as molecular probes to explore ligand binding sites of the α9α10 nAChR, but also have the potential to become candidates for drug development. From the perspectives of medicinal chemistry and pharmacology, we highlight the structure and function of the α9α10 nAChR and review studies of α-conotoxins targeting it, including their three-dimensional structures, structure optimization strategies, and binding modes at the α9α10 nAChR, as well as their therapeutic potential.


Assuntos
Conotoxinas , Antagonistas Nicotínicos , Receptores Nicotínicos , Animais , Química Farmacêutica , Conotoxinas/farmacologia , Antagonistas Nicotínicos/farmacologia , Receptores Nicotínicos/efeitos dos fármacos
15.
Toxins (Basel) ; 12(4)2020 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-32260499

RESUMO

Centipedes are among the oldest venomous arthropods that use their venom to subdue the prey. The major components of centipede venom are a variety of low-molecular-weight peptide toxins that have evolved to target voltage-gated ion channels to interfere with the central system of prey and produce pain or paralysis for efficient hunting. Peptide toxins usually contain several intramolecular disulfide bonds, which confer chemical, thermal and biological stability. In addition, centipede peptides generally have novel structures and high potency and specificity and therefore hold great promise both as diagnostic tools and in the treatment of human disease. Here, we review the centipede peptide toxins with reported effects on ion channels, including Nav, Kv, Cav and the nonselective cation channel polymodal transient receptor potential vanilloid 1 (TRPV1).


Assuntos
Proteínas de Artrópodes/farmacologia , Venenos de Artrópodes/farmacologia , Mordeduras e Picadas/metabolismo , Quilópodes/metabolismo , Descoberta de Drogas , Canais Iônicos/efeitos dos fármacos , Moduladores de Transporte de Membrana/farmacologia , Animais , Proteínas de Artrópodes/metabolismo , Venenos de Artrópodes/metabolismo , Humanos , Canais Iônicos/metabolismo , Moduladores de Transporte de Membrana/metabolismo , Conformação Proteica , Transdução de Sinais , Relação Estrutura-Atividade
16.
RSC Adv ; 10(4): 2141-2145, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-35494567

RESUMO

TRPV1 is a ligand-gated ion channel and plays an important role in detecting noxious heat and pain with an unknown mechanism. RhTx from Chinese red-headed centipede activates the TRPV1 channel through the heat activation pathway by binding to the outer pore region, and causes extreme pain. Here, we synthesized RhTx and its retro-isomer RL-RhTx. Their structures were investigated by their circular dichroic spectra and NMR spectra. The effect of RhTx and RL-RhTx on the currents of wild-type and mutants of TRPV1 indicated that RL-RhTx have comparable TRPV1 activation responses to RhTx. A mutagenesis study showed that four TRPV1 residues, including Leu461, Asp602, Tyr632 and Thr634, significantly contributed to the activation effects of RL-RhTx and RhTx, and both peptides probably bind with TRPV1 in similar binding modes. As a novel TRPV1 activator, RL-RhTx provides an essential powerful tool for the investigation of activation mechanisms of TRPV1.

17.
Polymers (Basel) ; 12(4)2020 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-32268559

RESUMO

Waterproof-breathable (WB) materials with outstanding waterproofness, breathability, and mechanical performance are critical in diverse consumer applications. Electrospun nanofibrous membranes with thin fiber diameters, small pore sizes, and high porosity have attracted significant attention in the WB fabric field. Hot-press treatment technology can induce the formation of inter-fiber fusion structures and hence improve the waterproofness and mechanical performance. By combining electrospinning and hot-press treatment technology, polyurethane/fluorinated polyurethane/thermoplastic polyurethane/alkylsilane-functionalized graphene (PU/FPU/TPU/FG) nanofiber WB fabric was fabricated. Subsequently, the morphologies, porous structure, hydrostatic pressure, water vapor transmission rate (WVTR), and stress-strain behavior of the nanofiber WB fabric were systematically investigated. The introduction of the hydrophobic FG sheet structure and the formation of the inter-fiber fusion structure greatly improved not only the waterproofness but also the mechanical performance of the nanofiber WB fabric. The optimized PU/FPU/TPU-50/FG-1.5 WB fabric exhibited an excellent comprehensive performance: a high hydrostatic pressure of 80.4 kPa, a modest WVTR of 7.6 kg m-2 d-1, and a robust tensile stress of 127.59 MPa, which could be used to achieve various applications. This work not only highlights the preparation of materials, but also provides a high-performance nanofiber WB fabric with huge potential application prospects in various fields.

18.
J Food Sci ; 85(7): 2198-2206, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32614078

RESUMO

The hemolytic property discourages the development of sea cucumber saponins on alleviating lipids metabolism disturbance. The hemolytic activity of saponins has been reported to be highly correlative to their chemical structures. The aim of this study was to reduce the hemolytic activity of sea cucumber-derived saponins echinoside A (EA) and simultaneously remain its effect on alleviating non-alcoholic fatty liver disease (NAFLD) by structural modifications. Administration with EA and its derivatives for 8 weeks remarkably mitigated orotic acid-induced NAFLD via inhibiting the activities and mRNA expressions of enzymes involved in lipogenesis, enhancing the activities and expressions of enzymes related to hepatic lipolysis in a rat model. Importantly, aglycone exhibited a distinct advantage in stimulating hepatic lipolysis compared with EA and dsEA, meanwhile possessed lowest hemolytic activity. This study may provide the theoretical basis to strengthen the application of sea cucumber saponins as food supplements and/or functional ingredients.


Assuntos
Holoturina/análogos & derivados , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Pepinos-do-Mar/química , Animais , Holoturina/administração & dosagem , Holoturina/química , Humanos , Metabolismo dos Lipídeos/efeitos dos fármacos , Lipogênese/efeitos dos fármacos , Lipólise/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/fisiopatologia , Ratos , Ratos Wistar , Saponinas/administração & dosagem , Saponinas/química
19.
Biochem Biophys Res Commun ; 389(4): 645-50, 2009 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-19766098

RESUMO

Human Ero1-Lalpha catalyzes the formation of disulfide bond and hence plays an essential role in protein folding. Understanding the mechanism of disulfide bond formation in mammals is important because of the involvement of protein misfolding in conditions such as diabetes, arthritis, cancer, and aging. However, the crystal structure of the enzyme is not available yet, which seriously hinders the understanding of biological function of Ero1-Lalpha. Based on the crystal structure of yeast Ero1p, a rational three-dimensional structural model of Ero1-Lalpha was built and the characteristics of the enzyme were hence investigated. The characteristic similarities and differences between Ero1-Lalpha and Ero1p were compared on the basis of computational and experimental results, providing the first insight into the structure-function relationships of the enzymes. Both calculation and experiment got the concordant conclusion that FAD binds more tightly with Ero1-Lalpha than Ero1p. In addition, the probable electron transfer pathway was proposed on the basis of the structural models.


Assuntos
Glicoproteínas de Membrana/química , Glicoproteínas de Membrana/metabolismo , Modelos Moleculares , Oxirredutases/química , Oxirredutases/metabolismo , Sequência de Aminoácidos , Transporte de Elétrons , Flavina-Adenina Dinucleotídeo/química , Flavina-Adenina Dinucleotídeo/metabolismo , Humanos , Glicoproteínas de Membrana/genética , Dados de Sequência Molecular , Oxirredutases/genética , Conformação Proteica , Alinhamento de Sequência , Relação Estrutura-Atividade
20.
Polymers (Basel) ; 11(2)2019 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-30960182

RESUMO

This paper studied the ballistic performance of 3D woven angle-interlock fabric reinforced composites with different types of panel construction. Two types of composites P10B and P17C were designed to have the same areal density of around 12 kg/m² although they both had different ply areal densities and consisted of different numbers of plies. Non-perforated ballistic impacts were conducted on the two types of panels under the same level of impact energy. Post-mortem examination on the non-perforated panels was conducted through the cross-sectional images, planar projected delamination and 3D damage volume extracted from the non-destructive tests. Three distinctive sections of damage were segmented from the non-perforated panels, each indicating different material failure modes upon impact. Under the same areal density, the coarser composite panel P10B with a larger ply areal density and fewer reinforcement plies would result in less damage. The damage volume of P10B is nearly one-third that of the P17C. The findings are instructive for the design of 3D woven fabric continuously reinforced composites with doubly-curved shapes.

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