Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
Plant Sci ; 336: 111817, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37562731

RESUMO

Carotenoid cleavage dioxygenase (CCD) gene family is organized in two subfamilies: (i) 9-cis epoxycarotenoid dioxygenase (NCED) genes and (ii) CCD genes. NCED genes are essential for catalyzing the first step of the abscisic-acid (ABA) biosynthesis, while CCD genes produce precursors of the strigolactones hormone. The functional characterization of these gene subfamilies has not been yet performed in chickpea and lentil. Herein, were identified and systematically characterized two NCED and five CCD genes in the chickpea and two NCED and six CCD genes in lentil. After in silico sequence analysis and phylogeny, the expression profile of the NCED/CCD genes was determined by meta-analysis and real-time PCR in plants under different stress conditions. Sequence data revealed that NCED/CCD genes are highly conserved between chickpea and lentil. This conservation was observed both at gene and protein sequence levels and phylogenetic relationships. Analysis of the promoter sequences revealed that all NCED/CCD genes have a considerable number of cis-regulatory elements responsive to biotic and abiotic stress. Protein sequence analysis evidenced that NCED/CCD genes share several conserved motifs and that they have a highly interconnected interaction network. Furthermore, the three-dimensional structure of these proteins was determined and indicated that some proteins have structures with considerable similarity. The meta-analysis revealed that NCED/CCD genes are dynamically modulated in different organs and under different stress conditions, but they have a positive correlation with plant tolerance. In accordance, real-time PCR data showed that both NCED and CCD genes are differentially modulated in plants under drought stress. In particular, CaNCED2, CaCCD5, LcNCED2, LcCCD1, and LcCCD2 genes have a positive correlation with improved plant tolerance to drought stress. Therefore, this study presented a detailed characterization of the chickpea and lentil NCED/CCD genes and provided new insights to improve abiotic stress tolerance in these two important crops.


Assuntos
Cicer , Dioxigenases , Lens (Planta) , Cicer/genética , Lens (Planta)/genética , Lens (Planta)/metabolismo , Filogenia , Dioxigenases/genética , Dioxigenases/metabolismo , Plantas/metabolismo , Proteínas de Plantas/metabolismo , Carotenoides/metabolismo , Estresse Fisiológico/genética , Regulação da Expressão Gênica de Plantas , Ácido Abscísico/metabolismo
2.
Carbohydr Polym ; 291: 119622, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-35698349

RESUMO

The comprehension of the mechanism entailing efficient solvation of cyclodextrins (CD) by green solvents is of great relevance to boost environmentally sustainable usages of smart supramolecular systems. Here, 1-ethyl-3-methylimidazolium acetate, an ecofriendly ionic liquid (IL), is considered as an excellent solvent for native CDs. This IL efficiently dissolves up to 40 wt.% ß- and γ-CD already at ambient temperature and X-ray scattering indicates that CDs do not tend to detrimental flocculation under these drastic concentration conditions. Simulation techniques reveal the intimate mechanism of CD solvation by the ionic species: while the strong hydrogen bonding acceptor acetate anion interacts with CD's hydroxyl groups, the imidazolium cation efficiently solvates the hydrophobic CD walls via dispersive interactions, thus hampering CD's hydrophobic driven flocking. Overall the amphiphilic nature of the proposed IL provides an excellent solvation environment for CDs, through the synergic action of its components.


Assuntos
Ciclodextrinas , Líquidos Iônicos , Imidazóis/química , Líquidos Iônicos/química , Solubilidade , Solventes/química
3.
Int J Biol Macromol ; 163: 817-823, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32653377

RESUMO

Biomimetic design represents an emerging field for improving knowledge of natural molecules, as well as to project novel artificial tools with specific functions for biosensing. Effective strategies have been exploited to design artificial bioreceptors, taking inspiration from complex supramolecular assemblies. Among them, size-minimization strategy sounds promising to provide bioreceptors with tuned sensitivity, stability, and selectivity, through the ad hoc manipulation of chemical species at the molecular scale. Herein, a novel biomimetic peptide enabling herbicide binding was designed bioinspired to the D1 protein of the Photosystem II of the green alga Chlamydomonas reinhardtii. The D1 protein portion corresponding to the QB plastoquinone binding niche is capable of interacting with photosynthetic herbicides. A 50-mer peptide in the region of D1 protein from the residue 211 to 280 was designed in silico, and molecular dynamic simulations were performed alone and in complex with atrazine. An equilibrated structure was obtained with a stable pocked for atrazine binding by three H-bonds with SER222, ASN247, and HIS272 residues. Computational data were confirmed by fluorescence spectroscopy and circular dichroism on the peptide obtained by automated synthesis. Atrazine binding at nanomolar concentrations was followed by fluorescence spectroscopy, highlighting peptide suitability for optical sensing of herbicides at safety limits.


Assuntos
Atrazina/farmacologia , Chlamydomonas reinhardtii/efeitos dos fármacos , Chlamydomonas reinhardtii/fisiologia , Fotossíntese , Complexo de Proteína do Fotossistema II/metabolismo , Sequência de Aminoácidos , Biomimética/métodos , Simulação de Dinâmica Molecular , Peptídeos/química , Fotossíntese/efeitos dos fármacos , Complexo de Proteína do Fotossistema II/química , Conformação Proteica , Espectrometria de Fluorescência , Termodinâmica
4.
Toxicol In Vitro ; 61: 104624, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31419504

RESUMO

Phosphatase PTP1B has become a therapeutic target for the treatment of type 2-diabetes, whereas recent studies have revealed that PTP1B plays a pivotal role in pathophysiology and development of breast cancer. Oleuropein is a natural, phenolic compound with anticancer activity. The aim of this study was to address the question whether PTP1B constitutes a target for oleuropein in breast cancer MCF-7 cells. The cellular MCF-7 breast cancer model was used in the study. The experiments were performed using cellular viability tests, Elisa assays, immunoprecipitation, flow cytometry analyses and computer modelling. Herein, we evidenced that the reduced activity of phosphatase PTP1B after treatment with oleuropein is strictly correlated with decreased MCF-7 cellular viability and cell cycle arrest. These results provide new insight into further research on oleuropein and possible role of the compound in adjuvant treatment of breast cancer.


Assuntos
Adenocarcinoma/tratamento farmacológico , Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Iridoides/farmacologia , Proteína Tirosina Fosfatase não Receptora Tipo 1/metabolismo , Adenocarcinoma/enzimologia , Antineoplásicos/química , Neoplasias da Mama/enzimologia , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Humanos , Glucosídeos Iridoides , Iridoides/química , Células MCF-7 , Simulação de Dinâmica Molecular , Proteína Tirosina Fosfatase não Receptora Tipo 1/química , Proteína Tirosina Fosfatase não Receptora Tipo 1/genética
5.
J Phys Chem B ; 113(27): 9235-40, 2009 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-19527015

RESUMO

We report on an experimental and simulation study done on a representative room temperature ionic liquid, namely tetradecyltrihexylphosphonium chloride, at ambient conditions. The study was conducted using small and wide angle X-ray scattering and molecular dynamics simulations. Both approaches converge in indicating that this material is characterized by the existence of strong P-Cl interactions (with characteristic distances between 3.5 and 5.0 A) and by the occurrence of nanoscale segregation, despite the symmetric nature of the cation and similarly to other room temperature ionic liquids. A good agreement is found between the structure factor and pair correlation functions obtained from MD simulations and the corresponding experimental observables, thus strongly validating the interaction potential used in the simulations.

6.
J Phys Chem B ; 111(9): 2166-73, 2007 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-17295534

RESUMO

The structure of poly(vinyl alcohol) (PVA) hydrogels formed as a result of freeze/thaw treatments of aqueous solutions of the polymer (11 wt % PVA) in the freshly prepared state is analyzed through the combined use of small (SANS) and ultrasmall (USANS) angle neutron scattering techniques. The structure of these hydrogels may be described in terms of polymer rich regions, with dimensions of the order of 1-2 microm, dispersed in a water rich phase, forming two bicontinuous phases. The PVA chains in the polymer rich phase form a network where the cross-linking points are mainly crystalline aggregates of PVA having average dimensions of approximately 45 A. The structural organization of freeze/thaw PVA hydrogel membranes does not change either after rehydration of dried gels or in the presence of a tensile force. Finally, addition of surfactant micelles inside the gel provides a formulation with both hydrophobic and hydrophilic regions, which demonstrates the potential of the system for drug delivery. Both SANS and EPR measurements show that sodium decylsulfate (C10OS) micelles do not significantly interact with the PVA gel. Variation of the gel structure by the number of freeze/thaw cycles should modulate the rate of release of an active constituent, for example, in a dermal patch.


Assuntos
Físico-Química/métodos , Hidrogéis/química , Álcool de Polivinil/química , Ácidos Sulfônicos/química , Biofísica/métodos , Sistemas de Liberação de Medicamentos , Espectroscopia de Ressonância de Spin Eletrônica , Teste de Materiais , Modelos Estatísticos , Nêutrons , Espalhamento de Radiação , Estresse Mecânico , Tensoativos/química , Resistência à Tração
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA