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1.
Methods Mol Biol ; 2564: 99-119, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36107339

RESUMO

Fluorescent proteins have revolutionized cell biology and cell imaging through their use as genetically encoded tags. Structural biology has been pivotal in understanding how their unique fluorescent properties manifest through the formation of the chromophore and how the spectral properties are tuned through interaction networks. This knowledge has in turn led to the construction of novel variants with new and improved properties. Here we describe the process by which fluorescent protein structures are determined, starting from recombinant protein production to structure determination by molecular replacement. We also describe how to incorporate and determine the structures of proteins containing non-natural amino acids. Recent advances in protein engineering have led to reprogramming of the genetic code to allow incorporation of new chemistry at designed residue positions, with fluorescent proteins being at the forefront of structural studies in this area. The impact of such new chemistry on protein structure is still limited; the accumulation of more protein structures will undoubtedly improve our understanding and ability to engineer proteins with new chemical functionality.


Assuntos
Aminoácidos , Código Genético , Aminoácidos/química , Corantes , Cristalização , Engenharia de Proteínas/métodos , Proteínas Recombinantes/genética
2.
Methods Mol Biol ; 2564: 223-246, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36107345

RESUMO

DNA binding fluorescent proteins are a powerful tool for single-molecule visualization. In this chapter, we discuss a protocol for the synthesis of DNA binding fluorescent proteins and visualization of single DNA molecules. This chapter includes stepwise methods for molecular cloning, reversible staining, two-color staining, sequence-specific staining, and microscopic visualization of single DNA molecules in a microfluidic device. This content will be useful for DNA characterization using DNA binding fluorescent proteins and its visualization at the single-molecule level.


Assuntos
Proteínas de Ligação a DNA , DNA , DNA/química , Proteínas de Ligação a DNA/metabolismo , Corantes Fluorescentes , Microscopia de Fluorescência/métodos , Coloração e Rotulagem
3.
Methods Mol Biol ; 2564: 259-268, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36107347

RESUMO

To date, fluorescent protein biosensors are widely used in research. In vivo, they can be applied to dynamically monitor several physiological parameters in various subcellular compartments. Redox-sensitive green fluorescent protein 2 (roGFP2) senses the glutathione redox potential via a disulfide bridge formed between neighboring beta-strands of its beta-barrel structure. As changes in redox state affect both excitation maxima of roGFP2 oppositely, sensor responses are ratiometric. The reaction mechanism of roGFP2 is well characterized and involves an intermediate S-glutathionylation step. Thus, roGFP2 is also used in enzymatic in vitro assays, e.g., assessing glutaredoxin kinetics. In addition to the fluorescent read-out, the roGFP2 redox state can also be determined by differential migration on a non-reducing SDS-PAGE. This read-out mode may be beneficial in some applications, e.g., if mass-spectrometric analysis of posttranslational cysteine modifications is desired. Here, we describe a protocol for gel-based fluorescent read-out of the roGFP2 redox state, as well as modification of free cysteines by maleimide-based reagents.


Assuntos
Cisteína , Glutarredoxinas , Cisteína/metabolismo , Dissulfetos , Glutarredoxinas/metabolismo , Glutationa/metabolismo , Proteínas de Fluorescência Verde/química , Maleimidas , Oxirredução
4.
Med Gas Res ; 13(1): 29-32, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35946220

RESUMO

Calcium ion-releasing ability of different calcium hydroxide-based pulp capping materials was comparatively evaluated in this study. Different brands of cements were taken from different manufacturers and categorized into three groups. Three different brands of Ca(OH)2 cements (Dycal, TheraCal, and Cal LC) were taken prepared by mixing and curing the cements as per the manufacturer's instructions. Consequently, ion release was measured after 7, 14, and 21 days by argon-based induction coupled plasma mass spectroscopy test. Within the limitations of this study, light-cured Ca(OH)2 cements released a higher amount of calcium ions compared with self-cured Ca(OH)2 cements. Theracal was found to be the highest light-cured calcium ion releasing materials throughout the period of 21 days. In conclusion, further clinical studies are warranted to substantiate the findings of this study.


Assuntos
Agentes de Capeamento da Polpa Dentária e Pulpectomia , Compostos de Alumínio/química , Argônio , Cálcio/química , Hidróxido de Cálcio/química , Íons , Espectrometria de Massas , Óxidos/química
5.
Med Gas Res ; 13(1): 33-38, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-35946221

RESUMO

In a previous study, in silico screening of the binding of almost all proteins in the Protein Data Bank to each of the five noble gases xenon, krypton, argon, neon, and helium was reported. This massive and rich data set requires analysis to identify the gas-protein interactions that have the best binding strengths, those where the binding of the noble gas occurs at a site that can modulate the function of the protein, and where this modulation might generate clinically relevant effects. Here, we report a preliminary analysis of this data set using a rational, heuristic score based on binding strength and location. We report a partial prioritized list of xenon protein targets and describe how these data can be analyzed, using arginase and carbonic anhydrase as examples. Our aim is to make the scientific community aware of this massive, rich data set and how it can be analyzed to accelerate future discoveries of xenon-induced biological activity and, ultimately, the development of new "atomic" drugs.


Assuntos
Proteoma , Xenônio , Criptônio/química , Criptônio/farmacologia , Neônio/farmacologia , Gases Nobres/química , Gases Nobres/metabolismo , Xenônio/química , Xenônio/farmacologia
6.
Food Chem ; 400: 134087, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36084599

RESUMO

Apergillus carbonarius and Aspergillus niger are the principal fungi that attack table grapes, and they are responsible for producing and contaminating these fruits with ochratoxin A. Packaging containing essential oils from Ocimum gratissimum L. and Ocimum basilicum L. encapsulated in poly(lactic acid) (PLA) nanofibers were produced, the antifungal and antiocratoxigenic activities against A. carbonarius and A. niger were evaluated in vitro and in vivo, and the effect of these packages on the quality of table grapes was determined. The nanofibers were produced by the Solution Blow Spinning technique and characterized by Scanning Electron Microscopy and Thermogravimetric Analysis. Fungal contamination and ochratoxin A production were significantly controlled by PLA nanofibers containing the essential oils and the physicochemical parameters of the grapes were preserved, preserving the quality and the shelf life of the fruit. Therefore, the active packaging developed herein has potential and may be suitable for application in fruits.


Assuntos
Nanofibras , Ocratoxinas , Ocimum basilicum , Ocimum , Óleos Voláteis , Vitis , Antifúngicos , Aspergillus , Aspergillus niger , Ocimum/química , Óleos Voláteis/química , Óleos Voláteis/farmacologia , Poliésteres , Vitis/química
7.
Food Chem ; 400: 134092, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36084600

RESUMO

Chiral analysis of food components can provide important information for food quality, bioactivity and safety. Determination of enantiomeric ratios in food is a tedious task, due to the poor resolution and insufficient sensitivity for simultaneous discrimination and quantification of trace amounts of d-form metabolites. Herein, a high-throughput, high-sensitive and high-resolution method was developed for simultaneously determining enantiomeric ratios of multiple chiral α-hydroxy/amino acids (HA/AAs) from fermented milks in one-run by [d0]/[d5]-estradiol-3-benzoate-17ß-chloroformate labeling-assisted ion mobility - mass spectrometry. Results revealed extensive variation in chiral HA/AA profiles among 15 fermented milks. A total of 14 D-HA/AAs were identified. d-Lactic acid and d-alanine appeared as the most discriminatory in fermented milks with live lactic acid bacteria (LAB). Results suggested that glycolysis, casein hydrolysis and enantioisomerization of HA/AAs were most likely affected by various starter culture LAB. It may contribute to entail a valuable step forward in food quality control and discovering functional-related chiral biomarkers.


Assuntos
Aminoácidos , Caseínas , Alanina/análise , Aminoácidos/análise , Animais , Benzoatos/análise , Caseínas/análise , Estradiol/análise , Hidroxiácidos/análise , Ácido Láctico/análise , Espectrometria de Massas/métodos , Leite/química , Estereoisomerismo
8.
Food Chem ; 400: 133873, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36087477

RESUMO

To overcome the low production efficiency of Pickering emulsion stabilizers prepared from starch, alcohol precipitation and surface modification were applied in this study. Spherical starch nanoparticles (StNPs) (247.90 ± 1.96 nm) were prepared through nanoprecipitation. The StNPs were surface-esterified to produce starch nanoparticle acetate (StNPAc), and the physicochemical changes of the products were investigated. The contact angle (>89.56° ± 0.56°) of StNPAc (degree of substitution, 0.53) was maintained for over 30 min. The results showed that the hydrophobicity of the StNPs was improved by shielding the surface hydroxyl groups via acetylation. StNPAc was also used to produce emulsions for further evaluation of their feasibility as Pickering emulsifiers. Oil-in-water (3:7, v/v) emulsions containing 1.5 wt% StNPAc were stabilized for over 35 days without creaming. Thus, StNPAc exhibited better emulsifying capacity and storage stability than StNPs. Therefore, hydrophobic starch nanoparticles obtained by acetylation are promising stabilizers for surfactant-free Pickering emulsions.


Assuntos
Nanopartículas , Amido , Acetatos , Emulsões/química , Excipientes , Nanopartículas/química , Tamanho da Partícula , Amido/química , Água/química
9.
Food Chem ; 400: 133965, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36087478

RESUMO

In the present study, in order to establish a triggerable system of core-shell structure, oregano essential oil (OEO) loaded microcapsules by chitosan-decorated titanium dioxide (TiO2) were prepared and characterized to explore their immediate triggered release abilities by UV-mediated triggers. The surface modification of chitosan composite shells could improve encapsulation yield and loose bulk density. Microcapsules loaded TiO2 were more conducive to release after UV irradiation and the mechanism involved in the release process was followed a classical Fickian diffusion. The microcapsules had higher thermal stability compared to free OEO but UV irradiation reduced the thermal stability of microcapsules with TiO2. Furthermore, the analysis of FTIR and XPS showed that the damaged shell structures were observed, especially glycosidic bonds, and were advantageous to the overflow of OEO. Therefore, loading TiO2 in core-shell system was a promising strategy for controlling the release by UV irradiation according to the needs.


Assuntos
Quitosana , Óleos Voláteis , Origanum , Cápsulas/química , Quitosana/química , Óleos Voláteis/química , Titânio
10.
Food Chem ; 400: 134036, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36087479

RESUMO

Multi-class antibiotic analysis in aquatic products is still challenging owing to the complex matrix and low co-extraction efficiency of various antibiotics. A facile and sensitive sample pretreatment method based on magnetic dispersive solid-phase extraction was thus developed via systematic optimization of extraction and purification procedure. The multi-class antibiotics can simultaneously be extracted by acetonitrile-2 % acetic acid. Amphiphilic magnetic particles and C18 were used as adsorbents to remove matrix interferences, affording significantly reduced matrix effects of analytes. Under the optimum conditions, satisfactory linearity, recovery, precision, and sensitivity were achieved. The method limits of quantification were 0.25-0.5 µg kg-1. Besides, it displayed obvious advantages in operation convenience and efficiency due to the usage of magnetic particles. The developed method was successfully used to analyze antibiotic residues in both freshwater and seafood products, manifesting its suitability for antibiotic residues analysis in aquatic products.


Assuntos
Resíduos de Praguicidas , Polímeros , Acetonitrilas/química , Antibacterianos/análise , Fenômenos Magnéticos , Resíduos de Praguicidas/análise , Polímeros/análise
11.
Food Chem ; 400: 133988, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36088888

RESUMO

The present study was designed to study the effect of green solvent processing in two folds, (i) to extract valuable protein from dairy and non-dairy expired milk products and (ii) to compare extraction efficiency and quality of extracted protein using conventional (CS) and green solvents (GS). Ethyl acetate, ethanol, isopropanol, n-heptane and cyclopentyl methyl ether (CPME) were selected as the GS for the possible substitution of hexane and ethyl ether. For each respective solvent, protein recovery, structural and functional modifications were studied. Protein yield was extracted most effectively by GS n-heptane in dairy milk (5.33 ± 0.01%) with a protein purity of 39.73 ± 0.90%. Non-dairy milk and product had similar protein yield when treated with CS and GS. Total mean of extraction efficiency, structural and functional modifications across all samples showed GS solvents were statistically more effective than CS.


Assuntos
Éteres Metílicos , Leite , 2-Propanol , Animais , Etanol , Etil-Éteres , Heptanos , Hexanos/química , Éteres Metílicos/química , Solventes/química
12.
Food Chem ; 400: 134118, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36088890

RESUMO

Carbohydrates and their implications for human health have been the subject to a rapidly growing interest. Substantial advances in analytical methods have enabled a more effective assessment of carbohydrates and their pharmacological effects. Developing a carbohydrate profile technology would surely aid the understanding of carbohydrate dietary impacts. With the advances in technology for characterization, as well as exploration of complex structure, it is becoming more feasible to synthesize such compounds, rather than isolation. Several technological developments, including improved analytical tools, glycomics, and automation technology, have opened up new opportunities to globally assess most carbohydrates in envisaged samples. The main analytical methods applied to carbohydrates are described. And then the development of automation technology in glycan synthesis are introduced. This review concludes by considering the limitations of the existing technologies and required future developments for overcoming these limitations and improving identification score and/or yield.


Assuntos
Carboidratos , Hexoses , Carboidratos/química , Humanos , Polissacarídeos/química
13.
Food Chem ; 400: 134110, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36096051

RESUMO

Soluble polysaccharides from white (PSW) and red (PSR) grape skins were obtained to be evaluated as potential modulators of the unbalanced astringency of a Tempranillo red wine. The modulation of astringency was evaluated by a sensory panel and it seemed to be related to the changes in the polyphenolic profile. Isothermal Titration Calorimetry (ITC) studies, employed to characterize flavan-3-ol-polysaccharide interactions, showed that PSR decreased noticeably wine astringency causing a great flavan-3-ol loss (ca. 40 %), since they interacted more spontaneously with the flavan-3-ols (ca. ΔGtotal = -2.14 × 104 cal/mol) than PSW (ca. ΔGtotal = -1.32 × 104 cal/mol). The strength of these interactions seems to be related to the polysaccharide molecular size and to the presence of arabinogalactans in the structure. On the contrary, PSW showed no relevant effects on wine astringency. Furthermore, potential variations of color were also assessed and no deleterious effect was observed after the addition of any polysaccharide.


Assuntos
Vitis , Vinho , Adstringentes , Polifenóis/química , Polissacarídeos/química , Vitis/química , Vinho/análise
14.
Braz. j. biol ; 83: e248931, 2023. tab
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1345525

RESUMO

Abstract Among several fruits, mangaba (Hancornia speciosa Gomes), it aroused the interest of producers and consumers due to its attractive sensory characteristics and health beneficial properties (high nutritional value and presence of bioactive substances), thus, this work evaluates the nutritional factors of the flour residue of mangaba processing that is despised by the food industry, and the influence of temperature on its production. The mangaba processing residue was splited in two main groups: in natura sample (control), and other for preparation of flour that was dried at 50 °C and divided into two other groups: treatment A (flour with roasts at 110 °C and 130 °C) and treatment B (flour from drying at 50 °C). The nutritional characteristics of flours were analyzed considering the chemical parameters: pH, titratable total acidity and soluble solids, in addition to the determination of moisture content, total lipids, total dietary fiber and ash, total energy value, antioxidant activity, phytochemical screening, quantification of phenolic compounds and flavonoids, as well as technological functional properties (water absorption index (WAI), water solubility index (WSI), milk absorption index (MAI) and milk solubility index (MSI) and oil absorption index (OAI). The results showed that the bioactive compounds present in the extracts do not have significant properties of acting as free radical kidnappers. The heat treatment, performed in the flour of mangaba processing residues, influenced the nutritional factors and properties of absorption and solubility, which showed statistical differences. These results show that the flour is a viable alternative for the energy enrichment of diets, contributing to the development of new products, the reduction of the disposal of these residues and consequently to the minimization of the environmental impact.


Resumo Dentre as diversas frutas a mangaba (Hancornia speciosa Gomes), despertou interesse de produtores e consumidores devido às suas características sensoriais atrativas e propriedades benéficas à saúde (elevado valor nutricional e presença de substâncias bioativas), assim, o trabalho avaliar os fatores nutricionais do resíduo da farinha de processamento de mangaba que é desprezado pela indústria alimentícia e, a influência da temperatura na sua produção. O resíduo de processamento da mangaba foi dividido em dois lotes, sendo um deles utilizado para as análises in natura (amostra controle) e o outro para a confecção da farinha que foi seca a 50 °C, e dividida em dois lotes: tratamento A (farinha com torras a 110 °C e 130 °C) e no tratamento B (farinha oriunda da secagem a 50 °C). Analisou-se as características nutricionais de farinhas considerando os parâmetros químicos: pH, acidez total titulável e sólidos solúveis, além da determinação do teor de umidade, lipídios totais, fibra alimentar total e cinzas, valor energético total, atividade antioxidante, triagem fitoquímica, quantificação de compostos fenólicos e flavonoides, bem como as propriedades funcionais tecnológicas (índice de absorção de água (IAA), índice de solubilidade em água (ISA), índice de absorção de leite (IAL) e índice de solubilidade em leite (ISL) e índice de absorção de óleo (IAO). Na análise foi inferido que os compostos bioativos presentes nos extratos não possuem propriedades significativas de agir como sequestradores de radicais livres. O tratamento térmico, realizado na farinha de resíduos de processamento de mangaba, influenciou nos dados dos fatores nutricionais e das propriedades de absorção e solubilidade, os quais apresentaram diferenças estatísticas. Estes resultados credenciam a farinha como uma alternativa viável para o enriquecimento energético de dietas, contribuindo para o desenvolvimento de novos produtos, a redução do descarte desses resíduos e consequentemente para a minimização do impacto ambiental.


Assuntos
Fibras na Dieta/análise , Farinha/análise , Frutas/química , Antioxidantes/análise , Valor Nutritivo
15.
Braz. j. biol ; 83: e242676, 2023. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1278552

RESUMO

Abstract Trees occurring on the margins of agricultural areas can mitigate damage from residual herbicides. Rhizospheric microbial activity associated with trees is one of the main remedial capacity indicators. The objective of this study was to evaluate the rhizospheric microbiological activity in tree species subjected to the herbicides atrazine and sulfentrazone via the rhizosphere. The experiment was designed in four blocks and a 6 × 3 factorial scheme. The first factor consisted of six tree species from Brazil and the second of atrazine, sulfentrazone, and water solutions. Four herbicide applications were performed via irrigation. The total dry mass of the plants, mycorrhizal colonization, number of spores, basal respiration of the rhizospheric soil, and survival rate of bioindicator plants after phytoremediation were determined. Trichilia hirta had higher biomass when treated with atrazine and sulfentrazone. Herbicides decreased the microbial activity in Triplaris americana and did not affect the microbiological indicators of Myrsine gardneriana, Schizolobium parahyba, and Toona ciliata. Fewer bioindicator plants survived in soil with Triplaris americana and sulfentrazone. Microbiological indicators were influenced in different ways between species by the presence of herbicides in the rhizosphere.


Resumo As árvores que ocorrem nas margens das áreas agrícolas podem mitigar os danos dos herbicidas residuais. A atividade microbiana rizosférica associada às árvores é um dos principais indicadores de capacidade corretiva. O objetivo deste trabalho foi avaliar a atividade microbiológica rizosférica em espécies arbóreas submetidas aos herbicidas atrazina e sulfentrazone via rizosfera. O experimento foi estruturado em quatro blocos e esquema fatorial 6 × 3. O primeiro fator consistiu em seis espécies de árvores do Brasil e o segundo em soluções de atrazine, sulfentrazone e água. Quatro aplicações de herbicidas foram realizadas via irrigação. Foram determinados a massa seca total das plantas, colonização micorrízica, número de esporos, respiração basal do solo rizosférico e taxa de sobrevivência de plantas bioindicadoras após fitorremediação. Trichilia hirta apresentou maior biomassa quando tratada com atrazina e sulfentrazone. Os herbicidas diminuíram a atividade microbiana em Triplaris americana e não afetaram os indicadores microbiológicos de Myrsine gardneriana, Schizolobium parahyba e Toona ciliata. Menos plantas bioindicadoras sobreviveram no solo com Triplaris americana e sulfentrazone. Os indicadores microbiológicos foram influenciados de formas distintas entre as espécies pela presença dos herbicidas na rizosfera.


Assuntos
Poluentes do Solo , Micorrizas/química , Herbicidas , Solo , Microbiologia do Solo , Árvores , Brasil , Raízes de Plantas/química , Plântula , Rizosfera
16.
Food Chem ; 398: 133832, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-35961170

RESUMO

The thermal-induced interaction between ß-conglycinin (7S) and cyanidin-3-O-glucoside (C3G) on the bioaccessibility and antioxidant capacity of C3G was investigated. High ratio of 7S to C3G (1:100) led to a more ordered secondary structure of 7S. Thermal treatment promoted the formation of 7S-C3G complexes via hydrophobic and hydrogen bonds but did not induce the formation of 7S-C3G covalent products. Thermal treatment at 65 °C and 121 °C enhanced the binding affinity of 7S-C3G complexes by 46.19 % and 1203 % compared with 25 °C. The 7S-C3G interaction decreased C3G bioaccessibility by 4.37 %, 8.74 %, and 46.37 % at 25 °C, 65 °C, and 121 °C. Diphenylpicrylhydrazyl (DPPH) and ABTS antioxidant capacity assay indicated an antagonistic effect between 7S and C3G. The increased binding affinity of C3G to 7S limited the bioaccessibility of C3G and promoted the antagonism of antioxidant capacity between 7S and C3G. 7S addition was detrimental to the antioxidant capacity and bioaccessibility of C3G in vitro after thermal processing.


Assuntos
Antioxidantes , Globulinas , Antocianinas/química , Antígenos de Plantas , Antioxidantes/metabolismo , Globulinas/metabolismo , Glucosídeos/química , Proteínas de Armazenamento de Sementes , Proteínas de Soja
17.
Food Chem ; 398: 133846, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-35961172

RESUMO

The unregulated usage of Cephalexin (CFX) in animal source food products has led to antimicrobial resistance (AMR) in humans. Graphene quantum dots (GQD) are zero-dimensional nanomaterials possessing both unique optical and electrical propertiesbased on their tuneable size that serves as an excellent signal enhancer. The fluorescence quenching and conductive properties of GQD were exploited for the detection of CFX. In this study, a zero-length conjugation approach was utilized to develop Cephalexin-Bovine Serum Albumin (CFX-BSA) conjugate and used to develop antibodies (Ab). Conjugated CFX-BSA Abs with GQD enhanced the electrochemical response of the sensor for sensitive detection of CFX. The fabricated electrode was optimised by Electrochemical Impedance Spectroscopy (EIS). The limit of detection for CFX was found to be 0.53 fM in standard buffer with negligible cross-reactivity against other ß-lactam antibiotics. The biofunctionalized electrode based on GQD-antibody may potentially be miniaturised for on-site detection of other antibiotics in food samples.


Assuntos
Técnicas Biossensoriais , Grafite , Pontos Quânticos , Antibacterianos , Anticorpos , Técnicas Biossensoriais/métodos , Cefalexina , Técnicas Eletroquímicas/métodos , Grafite/química , Humanos , Imunoensaio/métodos , Limite de Detecção , Pontos Quânticos/química
18.
Food Chem ; 398: 133834, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-35961174

RESUMO

Insoluble dietary fibre from citrus peels (CIDF) was found to have adsorption and inhibitory effect on the activity of pancreatic lipase (PL). CIDF-400 exhibited the greatest adsorption and activity inhibition effect on PL. The fluorescence quenching spectra indicated that CIDF could quench PL through a dynamic quenching process induced by the electrostatic interactions with only one binding site between them. The synchronous fluorescence and three-dimensional fluorescence spectra showed that CIDF might combine with PL to induce the increase in hydrophobicity and the reduction in polarity of tyrosine (Tyr) and tryptophan (Try) residues, which further led to the conformational alternations of PL. Moreover, circular dichroism (CD) showed that CIDF altered the secondary structure of PL, decreased α-helical structure content, and increased ß-sheet structure content, potentially resulting in PL structure opening and its active site exposure. This study provides new perspectives for the application of CIDFs produced from agricultural waste in regulating lipid metabolism.


Assuntos
Citrus , Lipase , Adsorção , Dicroísmo Circular , Citrus/química , Fibras na Dieta , Lipase/metabolismo , Pâncreas/metabolismo
19.
Food Chem ; 398: 133870, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-35963216

RESUMO

Food safety and quality assessment mechanisms are unmet needs that industries and countries have been continuously facing in recent years. Our study aimed at developing a platform using Machine Learning algorithms to analyze Mass Spectrometry data for classification of tomatoes on organic and non-organic. Tomato samples were analyzed using silica gel plates and direct-infusion electrospray-ionization mass spectrometry technique. Decision Tree algorithm was tailored for data analysis. This model achieved 92% accuracy, 94% sensitivity and 90% precision in determining to which group each fruit belonged. Potential biomarkers evidenced differences in treatment and production for each group.


Assuntos
Lycopersicon esculentum , Algoritmos , Inocuidade dos Alimentos , Lycopersicon esculentum/química , Aprendizado de Máquina , Espectrometria de Massas por Ionização por Electrospray
20.
Food Chem ; 398: 133851, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-35963217

RESUMO

Modulating the size and surface charge of nanocarriers provides an efficacious strategy to enhance bioavailability of encapsulated cargos through increased mucus penetration. In this study, mucus-permHeable soy protein nanoparticles (SPNPs) were successfully fabricated via gastrointestinal proteolysis coupled with heating and pH-shifting treatment. Results showed that treatment at 65 °C and 75 °C after proteolysis induced the assembly of α, ά, and ß subunits, forming a relatively loose structure. This facilitated further assembly upon pH-shifting, forming smaller-sized and less electronegative nanoparticles, which showed enhanced mucus permeability. However, treatment at 85 °C and 95 °C promoted stronger hydrophobic interactions and induced disulfide bond cross-linking between B and ß subunits, forming compact macro-aggregates with high ß-sheet structure. These larger-sized aggregates were less influenced by pH-shifting treatment, demonstrating limited mucus diffusion. This study provides a potential alternative to fabricate mucus-permeable nanoparticles, and established a relationship between protein subunit assembly behavior and its mucus permeability.


Assuntos
Nanopartículas , Proteínas de Soja , Portadores de Fármacos/química , Concentração de Íons de Hidrogênio , Hidrólise , Muco/metabolismo , Nanopartículas/química , Proteínas de Soja/química
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