Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 58
Filtrar
1.
Food Sci Biotechnol ; 33(5): 1207-1219, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38440689

RESUMO

Microbial treatment can reduce the antinutritional factors and allergenic proteins in corn-soybean meal mixture (CSMM), but the role of the microbial community in hypoallergenicity and digestibility during the fermentation process remains unclear. Therefore, the fermentation strains of Bacillus and LAB were determined, and the compatibility and fermentation process of two-stage solid fermentation composite bacteria were optimized, and the dynamic changes in physicochemical property and microbial community during two-stage fermentation were investigated. Results showed that Bacillus subtilis NCUBSL003 and Lactobacillus acidophilus NCUA065016 were the best fermentation combinations. The optimal fermentation conditions were inoculum 7.14%, solid-liquid ratio of 1:0.88 and fermentation time of 74.30 h. The contents of TI, ß-conglycinin and glycinin decreased significantly after fermentation. Besides, TCA-SP, small peptides and FAA increased. Bacillus and Lactobacillus were the main genera. Pathogenic bacteria genera were inhibited effectively. This study suggests the feasibility of two-stage fermentation in improving the nutrient values and safety of the CSMM. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-023-01426-7.

2.
Int J Biol Macromol ; 259(Pt 2): 129285, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38211907

RESUMO

Phenolic acids are promising inhibitors of polyphenol oxidase (PPO), but the effects of carboxyl group and pH on their inhibition effects are still unclear. In this study, methyl cinnamate, cinnamic acid and 4-carboxycinnamic acid were investigated by their inhibitory effects with pH varied from 6.8 to 5.0. Results showed that 4-carboxycinnamic acid had the strongest inhibitory effect on PPO, followed by cinnamic acid and methyl cinnamate. Acidic pH enhanced the inhibitory effects of cinnamic acid and its derivatives on PPO, and the enhancement degree, IC50 and Ki declining degree were followed as 4-carboxycinnamic acid > cinnamic acid > methyl cinnamate. Methyl cinnamate exhibited competitive inhibition on PPO, while cinnamic acid and 4-carboxycinnamic acid exhibited mixed-type inhibition. Inhibitors induced slight changes in the secondary and tertiary structures of PPO, which were enhanced by acidic pH. Molecular docking results showed that 4-carboxycinnamic acid exhibited the strongest binding ability, and the main interaction forces were around carboxyl groups, and acidic pH enhanced the binding effect through more interactions and lower binding energy. This study could provide new insights into industrial application of cinnamic acid and its derivatives for the control of enzymatic browning of fruits and vegetables.


Assuntos
Catecol Oxidase , Cinamatos , Catecol Oxidase/química , Simulação de Acoplamento Molecular , Concentração de Íons de Hidrogênio
3.
Sci Rep ; 13(1): 17385, 2023 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-37833363

RESUMO

To investigate the potential mechanism of Er-Xian decoction (EXD) in treating aplastic anemia (AA), the active components of EXD were screened by the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP), and the targets of the components were predicted by the Swiss Target Prediction database. AA targets were collected from the GeneCards, OMIM, DisGeNET, PharmGKB, DrugBank, and TTD databases, the intersection of AA targets and EXD targets was calculated, and an herb-component-target network was constructed by Cytoscape 3.7.2 software. The STRING database was used for protein‒protein interaction (PPI) analysis, and Cytoscape 3.7.2 software was used to construct a PPI network and perform topology analysis. The core targets were imported into the DAVID database for gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses. The molecular docking software AutoDock was used to measure the affinity between active components and key targets. Finally, we established a mouse model of AA and verified the key targets and signaling pathways of EXD by RT‒PCR, ELISA and Western blot analysis. A total of 53 active components were screened from EXD, 2516 AA-related targets were collected, and 195 common targets were obtained. An herb-component-target network and a PPI network were successfully constructed, and 36 core targets were selected from the PPI network. The main active components of EXD include luteolin, kaempferol, berberine, etc., and key targets include PIK3CA, AKT1, STAT3, etc. GO functional enrichment analysis showed that cell components, molecular functions and biological processes with significant correlations were macromolecular complexes, protein serine/threonine/tyrosine kinase activity and protein phosphorylation, respectively. KEGG pathway analysis showed that the pathways with significant correlations included the PI3K-Akt signaling pathway and JAK-STAT signaling pathway. Molecular docking results showed that the tested key targets had good affinity for the corresponding active components. In AA mice, we found that EXD significantly increased white blood cell count, red blood cell count, platelet count and hemoglobin levels, increased mRNA levels of PIK3CA, PIK3CD, AKT1, JAK2, STAT3 and MAPK1, and promoted phosphorylation of PI3K, AKT, ERK1/2 and STAT3. In summary, EXD acts on PI3K, AKT, STAT3 and other targets through berberine, luteolin, quercetin and other components to regulate the PI3K-Akt pathway, JAK-STAT pathway and other pathways, thus exerting its therapeutic effect on AA. This study explained the Chinese medicine theory of treating AA with EXD by tonifying kidney-yang and provides a scientific basis for the use of EXD in treating AA.


Assuntos
Anemia Aplástica , Berberina , Medicamentos de Ervas Chinesas , Animais , Camundongos , Anemia Aplástica/tratamento farmacológico , Farmacologia em Rede , Janus Quinases , Luteolina/farmacologia , Simulação de Acoplamento Molecular , Fosfatidilinositol 3-Quinases , Proteínas Proto-Oncogênicas c-akt , Fatores de Transcrição STAT , Transdução de Sinais , Classe I de Fosfatidilinositol 3-Quinases , Medicamentos de Ervas Chinesas/farmacologia
4.
J Sci Food Agric ; 103(11): 5588-5599, 2023 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-37066671

RESUMO

BACKGROUND: Solid-state fermentation (SSF) is a general approach for preparing food and feed, which not only improves nutrition but also provides prebiotics and metabolites. Although many studies have been conducted on the effects of fermentation on feed substrate, the dynamics of microbiota and metabolites in SSF remain unclear. Here, high-throughput sequencing combined with gas chromatography-quadrupole time-of-flight mass spectrometry was used to evaluate the dynamic changes of solid fermented soybean meal and corn mixed matrix inoculated with Bacillus pumilus and Limosilactobacillus fermentum. RESULTS: Generally, inoculated bacteria rapidly proliferated, accompanied by the degradation of macromolecular proteins and an increase in the content of small peptides, trichloroacetic acid-soluble protein, free amino acids and organic acids. Bacillus, Lactobacillus and Enterococcus dominated the whole fermentation process. 389 non-volatile metabolites and 182 volatile metabolites were identified, including amino acids, organic acids, ketones, aldehydes, furans and pyrazine. Typical non-volatile metabolites such as lactic acid, 4-aminobutanoic acid, l-glutamic acid, d-arabinose and volatile metabolites such as 4-ethyl-2-methoxyphenol, 4-penten-2-ol, 2-pentanone, 2-ethylfuran, 2-methylhexanoic acid and butanoic acid-ethyl ester were significantly increased in two-stage solid fermentation. However, some adverse metabolites were also produced, such as oxalic acid, acetic acid, tyramine and n-butylamine, which may affect the quality of fermented feed. Sixteen genera were significantly correlated with differential non-volatile metabolites, while 11 genera were significantly correlated with differential volatile metabolites. CONCLUSION: These results characterized the dynamic changes in the process of two-stage solid-state fermentation with Bacillus pumilus and Limosilactobacillus fermentum and provided a potential reference for additional intervention on improving the effectiveness and efficiency of solid-state fermentation of feed in the future. © 2023 Society of Chemical Industry.


Assuntos
Bacillus pumilus , Limosilactobacillus fermentum , Fermentação , Bacillus pumilus/metabolismo , Zea mays/metabolismo , Farinha , Bactérias/metabolismo , Aminoácidos/metabolismo
5.
J Sci Food Agric ; 103(8): 3830-3839, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36303537

RESUMO

BACKGROUND: Ultrasound-assisted glycation is a promising method for decreasing the allergenicity of α-lactalbumin (ALA). However, there is a lack of in vivo studies on the allergenicity of ultrasound-assisted glycated ALA. In this study, the effects of the ultrasound-assisted glycation of ALA on the allergenicity and intestinal microflora were characterized using a BALB/c mouse model. RESULTS: Increased immunoglobulin -G/ immunoglobulin-E (IgG/IgE) and interleukin-4/6 (IL-4/6) secretions, and reduced interferon-γ (IFN-γ) secretions were found in the serum of ALA sensitized and challenged, mice in comparison with a control group. However, there was no significant difference between the mice fed with ultrasound-assisted glycated ALA and the control group. Mice that were sensitized and challenged with ALA showed disrupted intestinal microflora, manifesting in significantly decreased Firmicutes and significantly increased Proteobacteria. It was found that 100ALA-gal could maintain the intestinal microflora of mice in a normal state. Pearson's rank correlation showed that Proteobacteria and Spirochaetota were correlated positively with the IL-4/IL-6 level and were correlated negatively with the expression of IFN-γ. Proteobacteria were also significantly positively correlated with IL-6 and negatively correlated with IFN-γ (P < 0.05). CONCLUSION: These results suggested that ultrasound-assisted glycation on ALA can maintain the intestinal microflora in a normal state thus balancing the proportion of Th1/Th2 to decrease allergic reaction. © 2022 Society of Chemical Industry.


Assuntos
Alérgenos , Lactalbumina , Animais , Camundongos , Alérgenos/química , Lactalbumina/química , Reação de Maillard , Interleucina-4 , Interleucina-6 , Imunoglobulina E , Interferon gama , Camundongos Endogâmicos BALB C
6.
Food Chem ; 399: 134013, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36037695

RESUMO

Ovalbumin (OVA)-glucose mixture was treated with Co-60 irradiation at 0-25 kGy, and effects of irradiation on the glycation and allergenicity of OVA were investigated. Irradiation induced glycation between OVA and glucose, reflected in the significant increase of glycation sites from 3 to 14. Interestingly, OVA irradiated at 25 kGy had three new glycated peptides (568.782+, 739.382+ and 509.752+). The degree of substitution per peptide molecule (DSP) of glycated peptides exhibited different trends with increasing irradiation dose. Particularly, glycated peptides 17-26, 55-60, 263-267 and 368-375 showed markedly decreased DSP values after irradiation at 20 and 25 kGy, which could be caused by the generation of Maillard reaction products (MRPs). MS/MS spectra suggested that neutral loss occurred in glycated arginine, whose structure was similar to MRPs. The IgG- and IgE-binding abilities of OVA significantly decreased with increasing irradiation dose, indicating that the protein allergenicity was reduced.


Assuntos
Alérgenos , Radioisótopos de Cobalto , Alérgenos/química , Ensaio de Imunoadsorção Enzimática , Glucose , Ovalbumina/química , Peptídeos/química , Espectrometria de Massas em Tandem
7.
J Agric Food Chem ; 70(30): 9477-9488, 2022 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-35881501

RESUMO

60Co gamma-ray irradiation-induced antigenicity changes in ovalbumin (OVA) were investigated, and the molecular mechanism was analyzed. Irradiation treatment at 0-100 kGy could significantly enhance the IgG/IgE binding ability of OVA in a dose-dependent paradigm by concomitant oxidative modification, which exhibited color browning and an increase in carbonyl content caused by high-penetrable rays. More allergenic epitopes of OVA were exposed after irradiation treatment reflected by structural changes including the unfolding of tertiary structure, the conversion of α-helix structures to ß-sheet and random coil structures, and the cleavage of several peptide bonds. Meanwhile, three oxidation sites of K46, T49, and N260 located in key linear epitopes were observed, which might increase the allergenic ability of OVA via the disaggregation of noncovalent bonds and the unwinding of α-helix structures. Conclusively, irradiation may enhance the potential allergenicity of OVA by oxidative modification, which provides theoretical guidance for effectively controlling the oxidation of proteins in the irradiation process.


Assuntos
Imunoglobulina E , Imunoglobulina G , Alérgenos/química , Epitopos , Imunoglobulina E/metabolismo , Imunoglobulina G/metabolismo , Espectrometria de Massas , Ovalbumina/química
8.
Food Chem ; 390: 133185, 2022 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-35567971

RESUMO

This study aimed to isolate and evaluate the allergenicity of glycated α-lactalbumin (ALA) digestive products and identify its allergenic peptides. The digestive products of native-, alone glycated- and ultrasound-assisted glycated ALA (ALA-D, ALA-gal-D, 100ALA-gal-D) were isolated into three fractions (F1, F2 and F3). High-resolution mass spectrometry showed that the digestion-resistant peptides of F2 and F3 mainly distributed in amino acid sequence (AA) 25-31, AA32-53, AA40-53, AA54-60, AA80-90, AA94-104. The allergenicity of the three fractions of glycated ALA was lower than that in ALA-D, indicating glycation of ALA could indeed reduce its allergenicity after digestion. Furthermore, most fractions isolated from high glycation-degree ALA had the lowest allergenicity. The IgG/IgE binding abilities of synthesized peptides indicated that AA94-104 firstly identified by us embodied the strongest allergenicity and might be the potential allergenic peptide. This will provide a theory for preparing hypoallergenic products based on the identified allergenic peptides.


Assuntos
Alérgenos , Lactalbumina , Alérgenos/química , Glicosilação , Lactalbumina/química , Espectrometria de Massas , Peptídeos
9.
Food Chem ; 374: 131616, 2022 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-34815116

RESUMO

The mechanism of d-allose in reducing the allergenicity and digestibility of ultrasound-pretreated α-lactalbumin (α-LA) was studied. The intensity reduction and peak red shift occurred in fluorescence spectra of glycated samples. Enzyme-linked immunosorbent assay and basophil degranulation analysis showed that d-allose significantly reduced the allergenicity of α-LA, and ultrasound-pretreated α-LA showed the lowest allergenicity after glycation. Compared with α-LA, the degree of hydrolysis decreased in glycated samples. Size-exclusion high-performance liquid chromatography showed that the glycated α-LA was resistant to digestive enzymes. The glycated sites and average degree of substitution per peptide molecule were determined using LC Orbitrap MS/MS. These results suggested that the masking of linear allergenic epitopes by glycation could reduce the allergenicity. Therefore, the combination of ultrasound pretreatment and glycation is a potential method to reduce protein allergenicity in food processing and provides a useful approach for the application of rare sugars in food processing.


Assuntos
Alérgenos , Lactalbumina , Glucose , Espectrometria de Massas em Tandem
10.
Foods ; 10(11)2021 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-34829039

RESUMO

Our previous studies indicated that ultrasound treatment can increase the anaphylaxis of protein. However, investigation on the anaphylaxis changes of ultrasound-treated α-lactalbumin (ALA) during digestion is lacking. The anaphylaxis of ultrasound-treated ALA and its digesta was investigated. The anti-digestive stable peptides were identified by high-resolution mass spectrometry. Ultrasound induced the tertiary structure of ALA to unfold and increased its anaphylaxis. During digestion, the anaphylaxis of both gastric and gastroduodenal digesta was further increased. There are two reasons for this phenomenon. On the one hand, linear epitopes played an important role in affecting anaphylaxis compared with the conformational epitope, and some linear epitopes were still retained on the anti-digestive stable peptides produced after gastroduodenal digestion, resulting in increased anaphylaxis after digestion. On the other hand, the presence of intact ALA molecules after digestion still remained strong anaphylaxis. Compared with the digesta of untreated ALA, the digesta of ultrasound-treated ALA possessed higher anaphylaxis. The results indicated that ultrasound increased the anaphylaxis of ALA during digestion.

11.
J Agric Food Chem ; 69(24): 6850-6859, 2021 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-34114451

RESUMO

Physical-assisted chemical modification is effective to reduce the allergenicity of α-lactalbumin (ALA). However, there are few in-depth studies on the allergenicity changes of physical-assisted chemical-modified ALA during digestion. The effect of gastroduodenal digestion on the allergenicity changes of ALA treated by sonication-assisted glycation was assessed. Digestion of both ALA and its glycated forms generated peptide fractions, and intact undigested glycated ALA in the hydrolysates still covalently bound to d-galactose. High-resolution mass spectrometry revealed that a higher glycation degree was discovered in sonication-preprocessed ALA compared to native ALA. Enzyme-linked immunosorbent assay and basophil degranulation showed that sonication-assisted glycation could significantly reduce ALA allergenicity. The allergenicity of both gastric and gastroduodenal hydrolysates was further increased, and the hydrolysates of sonication-assisted glycated ALA showed the lowest allergenicity. The reason could be the shielding effect of the linear epitope found to be caused by a higher glycation degree; although linear epitopes were exposed, d-galactose covalently bound to intact undigested glycated ALA in the hydrolysates retained its masking role. These results indicated that sonication-assisted glycation could be a promising method to prepare immunotherapeutic agents for allergen immunotherapy to achieve the purpose of allergy desensitization.


Assuntos
Alérgenos , Lactalbumina , Digestão , Imunoglobulina E , Sonicação
12.
Anal Bioanal Chem ; 413(1): 83-102, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33164151

RESUMO

Exosomes are a type of extracellular vesicle actively secreted by almost all eukaryotic cells. They are ideal candidates for reliable next-generation biomarkers in the early diagnosis and therapeutic response evaluation of cancer. Thus, the quantification of exosomes is crucial in facilitating clinical research and application. Compared with traditional materials, nanomaterials have better optical, magnetic, electrical, and catalytic properties due to their small size, high specific surface area, and variable structure. The incorporation of nanomaterials into sensing systems is an attractive approach towards improving sensitivity and can provide improved sensor selectivity and stability. In this paper, we summarize the progress in nanomaterial-based exosome detection methods, including electrochemical biosensors, photoelectrochemical biosensors, colorimetric biosensors, fluorescence biosensors, chemiluminescence biosensors, electrochemiluminescence biosensors, surface plasmon resonance biosensors, and surface-enhanced Raman spectroscopy biosensors. Moreover, future research directions and challenges in exosome detection methods are discussed. We hope that this article will offer an overview of nanomaterial-based exosome detection techniques and open new avenues in disease research.Graphical abstract.


Assuntos
Técnicas Biossensoriais , Exossomos/metabolismo , Nanoestruturas , Técnicas Eletroquímicas/métodos , Humanos , Biópsia Líquida/métodos , Neoplasias/diagnóstico , Análise Espectral/métodos
13.
Spectrochim Acta A Mol Biomol Spectrosc ; 239: 118544, 2020 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-32502816

RESUMO

In this paper, the composites of Fe3O4 modified by sodium lignosulfonate and copper peroxide (Fe3O4@CP) were produced by a simple two-step method, and their morphology and composition were featured in Field emission scanning electron microscopy, X-ray powder diffraction, X-ray diffraction and Fourier transform infrared. Then, Fe3O4@CP catalyzed the oxidation of colorless 3,3',5,5'-tetramethylbenzidine to blue oxide in the presence of H2O2, indicating that it had good catalytic performance. Further, the experimental conditions were optimized, including time, pH, temperature and material concentration. The kinetic analysis results showed that Fe3O4@CP exhibited excellent catalytic performance and its catalytic kinetic plot conformed to the Michaelis-Menten equation and the catalytic mechanism was consistent with the ping-pong mechanism. Finally, a H2O2 colorimetric assay with a linear range of 0.2-300 µM and a detection limit of 0.11 µM was constructed. In addition, due to the decolorization reaction of ox-TMB with glutathione and the scavenging effect of GSH on hydroxyl radicals (·OH), a glutathione colorimetric assay was further constructed with a linear range of 0.2-40 µM and a detection limit of 0.05 µM. It also verified that the assay had excellent selectivity and stability and could be utilized to detect actual samples.


Assuntos
Colorimetria , Peroxidase , Catálise , Cobre , Glutationa , Peróxido de Hidrogênio , Cinética , Lignina/análogos & derivados , Peroxidase/metabolismo , Peroxidases , Sódio
14.
J Agric Food Chem ; 68(22): 6065-6075, 2020 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-32396375

RESUMO

Ovalbumin (OVA) is one of the major food allergens in hen eggs. In this work, it was demonstrated that glycation with d-glucose and its epimers, including d-mannose, d-allose, d-galactose, and l-idose, could effectively attenuate the IgG/IgE binding of OVA, which was attributed to the covalent masking by sugars and to its structural changes. The glycation sites were determined, and their average degree of substitution was found using liquid chromatography coupled with high-resolution mass spectrometry. Fluctuations in OVA conformation were monitored by conventional spectrometry. Compared to those of OVA-Man and OVA-Glu, OVA-All, OVA-Gal, and OVA-Ido showed a higher glycation extent, and the alterations on their steric layouts were more drastic, suggesting that the configuration of hydroxyl groups at positions C-3, C-4, and C-5 in sugars might be important for the glycation reactivity; as such, their capabilities in binding with IgG/IgE decreased more significantly. Attempts were made to provide valuable information for in-depth understanding of the differences in biochemical functionality among epimeric sugars. These insights would be helpful for designing sweetened food products with a desirable level of safety.


Assuntos
Hipersensibilidade a Ovo/imunologia , Imunoglobulina E/imunologia , Imunoglobulina G/imunologia , Ovalbumina/imunologia , Animais , Galinhas , Ovos/análise , Galactose/química , Galactose/imunologia , Glucose/química , Glucose/imunologia , Glicosilação , Hexoses/química , Hexoses/imunologia , Humanos , Manose/química , Manose/imunologia , Espectrometria de Massas , Ovalbumina/química
15.
Transl Cancer Res ; 9(1): 42-48, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35117156

RESUMO

BACKGROUND: As a standard treatment modality, radiotherapy (RT) has been widely employed for cancer treatment. In addition to directly killing tumor cells, RT is known for its immunomodulatory effects. Nevertheless, the effects of ionizing radiation on immune reactions, as well as their underpinning mechanisms, are complex and remain unclear. METHODS: The immunomodulatory effects of ionizing irradiation were dynamically monitored by concomitant assessment of peripheral blood lymphocytes, and Th1 (CD3+CD4+IFN-r+), Th2 (CD3+CD4+IL-4+), Tc1 (CD3+CD8+IFN-r+) and Tc2 (CD3+CD8+IL-4+) cells, along with CD25, CD28, CTLA-4, PD-1, Foxp3, TGF-ß, and IL-10 gene expression levels in 30 lung cancer patients who underwent RT. RESULTS: Local cancer RT activated cellular immune reactions, which was reflected by an obvious reduction of B cells and increased CD8 and NK cell amounts, and consequent increase of suppressor T cells (Ts). Further investigation showed that Th2 and Tc2 responses were significantly increased while Th1 and Tc1 were decreased. CONCLUSIONS: The immunomodulatory effects mediated by RT are characterized by a shift from humoral to cellular immunity, significant augmentation of CD8 and Ts subpopulation, and Th2 and Tc2 responses, indicating an immuno-activating response, which might be beneficial for initial antitumor immune reactions, but may not affect the later ones. Immunomodulatory therapy should be performed upon RT to restore the immune balance for maintaining a Th1/Tc1 dominant immunity to achieve long-term anticancer immunity.

16.
J Agric Food Chem ; 67(11): 3096-3105, 2019 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-30821964

RESUMO

Glycation between ovalbumin (OVA) and different monoses under mild dry heating at 37 °C was studied. The content of free amino groups decreased dramatically, and the conformational changes based on fluorescence and circular dichroism spectra were evident in glycated OVA. The glycated sites and the average degree of substitution per peptide molecule per site were determined using liquid chromatography high-resolution mass spectrometry. Lysine and arginine were the predominant glyaction sites, in which Lys207 was a relatively reactive site for glycation in all of the conjugates. In general, the extent of glycation of aldose was higher, and its alterations on the steric layouts of protein were more drastic than those of ketose. The configuration of hydroxyl groups at C-4 in sugar epimers might be important for the glycation reactivity and conformational modification in the glycated proteins. These insights would have important implications for the creation of sweetened food products with desirable structures and excellent quality control.


Assuntos
Ovalbumina/química , Carboidratos/química , Glicosilação , Peptídeos/química , Conformação Proteica , Análise Espectral
17.
Fish Physiol Biochem ; 45(1): 231-243, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30387032

RESUMO

Cadmium (Cd) is known to be a potentially toxic heavy metals to the fish health and growth. Carassius auratus gibelio (C. a. gibelio) specimens were exposed to waterborne Cd (0, 0.05, 0.10, 0.15, and 0.20 mg/L CdCl2) for 14 days. Cd accumulation, liver and intestine histopathology, and intestinal microorganism were investigated in the present study. The results indicated that Cd accumulation in the gill, liver, intestine, and muscle gradually decreased as Cd concentration increased. The gill accumulated higher amounts of Cd than other tissues. The histopathology of liver and intestine underwent changes with different Cd concentrations, including hepatocyte hypertrophy, aggregation of blood cells, sinusoids, lipidosis, necrosis of hepatic tissues, the erosion of villi, necrosis in the mucosal layer, the appearance of vacuoles in the lamina propria, hyperplasia, and swelling of goblet cells. Moreover, the core gut microbiota existed in the intestinal microorganism and did not change as Cd concentration increased. However, the diversity of intestinal microorganism was significantly reduced compared with that of the control sample. The present results indicated that C. a. gibelio exposed to Cd suffered toxicity, and Cd could affect the biodiversity of the intestinal microbiota of C. a. gibelio.


Assuntos
Cádmio/metabolismo , Cádmio/toxicidade , Carpa Dourada , Intestinos/microbiologia , Poluentes Químicos da Água/toxicidade , Animais , Brânquias , Intestinos/efeitos dos fármacos
18.
Food Chem ; 268: 171-178, 2018 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-30064745

RESUMO

In general, the reducing sugars were extensively utilized as additives to prevent denaturation and inactivation during the freeze-drying process. However, different additives have unequal protective effects on the protein conformation. To evaluate the mechanism of protection the protein structure using different additives in the freeze-drying process, the glycated sites and degree of substitution per peptide (DSP) of each site were investigated by LC-Orbitrap MS. We found that the ovalbumin that was supplemented with ribose and then lyophilized (R-oval) have the highest extent of glycation modification. K227 was the most reactive glycated site in R-Oval, with a DSP of 0.83. The ovalbumin that was supplemented with lactose and then lyophilized (L-Oval) have the lowest degree of glycation, and K227 did not undergo the glycation reaction. It was hypothesized that the order impact of different additives on protection of the protein conformation were lactose > galactose > ribose during the freeze-drying process.


Assuntos
Liofilização/métodos , Ovalbumina/química , Açúcares/química , Cromatografia Líquida , Glicosilação , Espectrometria de Massas em Tandem
19.
Onco Targets Ther ; 11: 2131-2139, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29899663

RESUMO

BACKGROUND: Previous studies have demonstrated the prognostic value of globulin (GLB), albumin (ALB), the ALB/GLB ratio (AGR), body mass index (BMI), hemoglobin (Hb), and prognostic nutritional index (PNI) in breast cancer. The underlying mechanism has been investigated by examining the impact of nutritional parameters on T cells, natural killer cells, and dendritic cells, but little is known about their effect on checkpoint molecules. METHODS: Here, we investigated the correlation of mRNA expression of programmed cell death protein 1 (PD-1), cluster of differentiation 28 (CD28), cytotoxic T-lymphocyte antigen-4 (CTLA-4), and cluster of differentiation 25 (CD25) with AGR, ALB, GLB, total protein, pre-ALB, Hb, BMI, and PNI in the peripheral blood of breast cancer patients. One hundred and three patients and 21 age- and sex-matched healthy controls were enrolled. Quantitative real-time PCR was used to test relative mRNA expression. RESULTS: The results indicated that the mRNA levels of PD-1 and CD25 were 5.2- and 3.3-fold higher in patients with low AGR than in those with high AGR (P < 0.05). The mRNA levels of PD-1 were 3.5-fold higher in patients with high GLB than in those with low GLB (P < 0.05). In addition, breast cancer patients had higher expression levels of PD-1, CD28, CTLA-4, and CD25 mRNA in their peripheral blood compared with healthy volunteers (P < 0.05). CONCLUSION: These results suggest that AGR is negatively correlated with PD-1 and CD25 mRNA levels, while GLB is positively associated with PD-1 mRNA levels. Nutritional status in breast cancer patients may influence the PD-1 pathway and have implications for the optimization of cancer therapy.

20.
J Agric Food Chem ; 66(22): 5691-5698, 2018 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-29758985

RESUMO

Bovine α-lactalbumin (α-LA) is one of major food allergens in cow's milk. The present work sought to research the effects of ultrasonic pretreatment combined with dry heating-induced glycation between α-LA and galactose on the immunoglobulin E (IgE)/immunoglobulin G (IgG)-binding ability and glycation extent of α-LA, determined by inhibition enzyme-linked immunosorbent assay and high-resolution mass spectrometry, respectively. The IgE/IgG-binding ability of glycated α-LA was significantly decreased as a result of ultrasonic pretreatment, while the average molecular weight, incorporation ratio (IR) value, location and number of glycation sites, and degree of substitution per peptide (DSP) value were elevated. When the mixtures of α-LA and galactose were pretreated by ultrasonication at 150 W/cm2, glycated α-LA possesses seven glycation sites, the highest IR and DSP values, and the lowest IgE/IgG-binding ability. Therefore, the decrease in the IgE/IgG-binding ability of α-LA depends upon not only the shielding effect of the linear epitope found to be caused by the glycation of K13, K16, K58, K93, and K98 sites but also the intensified glycation extent, which reflected in the increase of the IR value, the number of glycation sites, and the DSP value. Moreover, allergenic proteins and monosaccharides pretreated by ultrasonication and then followed by dry-state glycation were revealed as a promising way of achieving lower allergenicity of proteins in food processing.


Assuntos
Imunoglobulina E/química , Imunoglobulina G/química , Lactalbumina/química , Animais , Glicosilação , Imunoglobulina E/imunologia , Imunoglobulina G/imunologia , Lactalbumina/imunologia , Espectrometria de Massas , Leite/química , Leite/imunologia , Ultrassom
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA