RESUMEN
Dipeptidyl peptidase-IV (DPPIV) inhibitory peptides are a class of antihyperglycemic drugs used in the treatment of type 2 diabetes mellitus, a metabolic disorder resulting from reduced levels of the incretin hormone GLP-1. Given that DPPIV degrades incretin, a key regulator of blood sugar levels, various antidiabetic medications that inhibit DPPIV, such as vildagliptin, sitagliptin, and linagliptin, are employed. However, the potential side effects of these drugs remain a matter of debate. Therefore, we aimed to investigate food-derived peptides from Cannabis sativa (hemp) seeds. Our developed bioinformatics pipeline was used to identify the putative hydrolyzed peptidome of three highly abundant proteins: albumin, edestin, and vicilin. These proteins were subjected to in silico digestion by different proteases (trypsin, chymotrypsin, and pepsin) and then screened for DPPIV inhibitory peptides using IDPPIV-SCM. To assess potential adverse effects, several prediction tools, namely, TOXINpred, AllerCatPro, and HemoPred, were employed to evaluate toxicity, allergenicity, and hemolytic effects, respectively. COPID was used to determine the amino acid composition. Molecular docking was performed using GalaxyPepDock and HPEPDOCK, 3D visualizations were conducted using the UCSF Chimera program, and MD simulations were carried out with AMBER20 MD software. Based on the predictive outcomes, FNVDTE from edestin and EAQPST from vicilin emerged as promising candidates for DPPIV inhibitors. We anticipate that our findings may pave the way for the development of alternative DPPIV inhibitors.
Asunto(s)
Cannabis , Dipeptidil Peptidasa 4 , Inhibidores de la Dipeptidil-Peptidasa IV , Hipoglucemiantes , Péptidos , Semillas , Humanos , Cannabis/química , Biología Computacional/métodos , Dipeptidil Peptidasa 4/metabolismo , Dipeptidil Peptidasa 4/química , Inhibidores de la Dipeptidil-Peptidasa IV/química , Inhibidores de la Dipeptidil-Peptidasa IV/farmacología , Hidrólisis , Hipoglucemiantes/farmacología , Hipoglucemiantes/química , Simulación del Acoplamiento Molecular , Péptidos/química , Proteínas de Plantas/química , Proteínas de Almacenamiento de Semillas/química , Semillas/químicaRESUMEN
Understanding the transport mechanism is crucial for developing inhibitors that block allergen absorption and transport and prevent allergic reactions. However, the process of how beta-conglycinin, the primary allergen in soybeans, crosses the intestinal mucosal barrier remains unclear. The present study indicated that the transport of beta-conglycinin hydrolysates by IPEC-J2 monolayers occurred in a time- and quantity-dependent manner. The beta-conglycinin hydrolysates were absorbed into the cytoplasm of IPEC-J2 monolayers, while none were detected in the intercellular spaces. Furthermore, inhibitors such as methyl-beta-cyclodextrin (MßCD) and chlorpromazine (CPZ) significantly suppressed the absorption and transport of beta-conglycinin hydrolysates. Of particular interest, sodium cromoglycate (SCG) exhibited a quantity-dependent nonlinear suppression model on the absorption and transport of beta-conglycinin hydrolysates. In conclusion, beta-conglycinin crossed the IPEC-J2 monolayers through a transcellular pathway, involving both clathrin-mediated and caveolae-dependent endocytosis mechanisms. SCG suppressed the absorption and transport of beta-conglycinin hydrolysates by the IPEC-J2 monolayers by a quantity-dependent nonlinear model via clathrin-mediated and caveolae-dependent endocytosis. These findings provide promising targets for both the prevention and treatment of soybean allergies.
Asunto(s)
Antígenos de Plantas , Clorpromazina , Cromolin Sódico , Globulinas , Proteínas de Almacenamiento de Semillas , Proteínas de Soja , Globulinas/metabolismo , Globulinas/farmacología , Globulinas/química , Proteínas de Almacenamiento de Semillas/metabolismo , Proteínas de Almacenamiento de Semillas/farmacología , Proteínas de Almacenamiento de Semillas/química , Antígenos de Plantas/metabolismo , Proteínas de Soja/metabolismo , Proteínas de Soja/química , Animales , Cromolin Sódico/farmacología , Clorpromazina/farmacología , Endocitosis/efectos de los fármacos , beta-Ciclodextrinas/farmacología , beta-Ciclodextrinas/química , Línea Celular , Transporte Biológico/efectos de los fármacos , Glycine max/metabolismo , Glycine max/química , Mucosa Intestinal/metabolismo , Mucosa Intestinal/efectos de los fármacos , PorcinosRESUMEN
Soybean ß-conglycinin is a major allergen that adversely affects the nutritional properties of soybean. Soybean deficient in ß-conglycinin is associated with low allergenicity and high nutritional value. Long intergenic noncoding RNAs (lincRNAs) regulate gene expression and are considered important regulators of essential biological processes. Despite increasing knowledge of the functions of lincRNAs, relatively little is known about the effects of lincRNAs on the accumulation of soybean ß-conglycinin. The current study presents the identification of a lincRNA lincCG1 that was mapped to the intergenic noncoding region of the ß-conglycinin α-subunit locus. The full-length lincCG1 sequence was cloned and found to regulate the expression of soybean seed storage protein (SSP) genes via both cis- and trans-acting regulatory mechanisms. Loss-of-function lincCG1 mutations generated using the clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9) system led to the deficiency of the allergenic α'-, α-, and ß-subunits of soybean ß-conglycinin as well as higher content of proteins, sulfur-containing amino acids, and free arginine. The dominant null allele LincCG1, and consequently, the ß-conglycinin-deficient phenotype associated with the lincCG1-gene-edited line was stably inherited by the progenies in a Mendelian fashion. The dominant null allele LincCG1 may therefore be exploited for engineering/developing novel hypoallergenic soybean varieties. Furthermore, Cas9-free and ß-conglycinin-deficient homozygous mutant lines were obtained in the T1 generation. This study is the first to employ the CRISPR/Cas9 technology for editing a lincRNA gene associated with the soybean allergenic protein ß-conglycinin. Moreover, this study reveals that lincCG1 plays a crucial role in regulating the expression of the ß-conglycinin subunit gene cluster, besides highlighting the efficiency of employing the CRISPR/Cas9 system for modulating lincRNAs, and thereby regulating soybean seed components.
Asunto(s)
Antígenos de Plantas , Sistemas CRISPR-Cas , Edición Génica , Globulinas , Glycine max , ARN Largo no Codificante , Proteínas de Almacenamiento de Semillas , Proteínas de Soja , Proteínas de Almacenamiento de Semillas/genética , Proteínas de Almacenamiento de Semillas/química , Globulinas/genética , Globulinas/metabolismo , Globulinas/química , Glycine max/genética , Glycine max/metabolismo , Antígenos de Plantas/genética , Antígenos de Plantas/química , Proteínas de Soja/genética , Proteínas de Soja/metabolismo , Proteínas de Soja/química , ARN Largo no Codificante/genética , Regulación de la Expresión Génica de las Plantas , Semillas/genética , Semillas/metabolismo , Semillas/químicaRESUMEN
As a natural low-calorie sweetener, Mogroside V (Mog-V) has gradually become one of the alternatives to sucrose with superior health attributes. However, Mog-V will bring unpleasant aftertastes when exceeding a threshold concentration. To investigate the possibility of soy protein isolates (SPIs), namely ß-conglycinin (7S), and glycinin (11S) as flavor-improving agents of Mog-V, the binding mechanism between Mog-V and SPIs was explored through multi-spectroscopy, particle size, zeta potential, and computational simulation. The results of the multi-spectroscopic experiments indicated that Mog-V enhanced the fluorescence of 7S/11S protein in a static mode. The binding affinity of 7S-Mog-V was greater compared with 11S-Mog-V. Particle size and zeta potential analysis revealed that the interaction could promote aggregation of 7S/11S protein with different stability. Furthermore, computational simulations further confirmed that Mog-V could interact with the 7S/11S protein in different ways. This research provides a theoretical foundation for the development and application of SPI to improve the flavor of Mog-V, opening a new avenue for further expanding the market demand for Mog-V.
Asunto(s)
Proteínas de Soja , Edulcorantes , Proteínas de Soja/química , Proteínas de Soja/metabolismo , Edulcorantes/química , Edulcorantes/metabolismo , Globulinas/química , Globulinas/metabolismo , Unión Proteica , Antígenos de Plantas/química , Antígenos de Plantas/metabolismo , Simulación por Computador , Proteínas de Almacenamiento de Semillas/química , Proteínas de Almacenamiento de Semillas/metabolismo , Simulación del Acoplamiento Molecular , TriterpenosRESUMEN
Allergenicity of soybean 7S protein (7S) troubles many people around the world. However, many processing methods for lowering allergenicity is invalid. Interaction of 7S with phenolic acids, such as chlorogenic acid (CHA), to structurally modify 7S may lower the allergenicity. Hence, the effects of covalent (C-I, periodate oxidation method) and noncovalent interactions (NC-I) of 7S with CHA in different concentrations (0.3, 0.5, and 1.0 mM) on lowering 7S allergenicity were investigated in this study. The results demonstrated that C-I led to higher binding efficiency (C-0.3:28.51 ± 2.13%) than NC-I (N-0.3:22.66 ± 1.75%). The C-I decreased the α-helix content (C-1:21.06%), while the NC-I increased the random coil content (N-1:24.39%). The covalent 7S-CHA complexes of different concentrations had lower IgE binding capacity (C-0.3:37.38 ± 0.61; C-0.5:34.89 ± 0.80; C-1:35.69 ± 0.61%) compared with that of natural 7S (100%), while the noncovalent 7S-CHA complexes showed concentration-dependent inhibition of IgE binding capacity (N-0.3:57.89 ± 1.23; N-0.5:46.91 ± 1.57; N-1:40.79 ± 0.22%). Both interactions produced binding to known linear epitopes. This study provides the theoretical basis for the CHA application in soybean products to lower soybean allergenicity.
Asunto(s)
Antígenos de Plantas , Ácido Clorogénico , Glycine max , Inmunoglobulina E , Proteínas de Soja , Ácido Clorogénico/química , Ácido Clorogénico/farmacología , Glycine max/química , Glycine max/inmunología , Inmunoglobulina E/inmunología , Proteínas de Soja/química , Proteínas de Soja/inmunología , Antígenos de Plantas/química , Antígenos de Plantas/inmunología , Humanos , Hipersensibilidad a los Alimentos/inmunología , Alérgenos/química , Alérgenos/inmunología , Unión Proteica , Proteínas de Almacenamiento de Semillas/química , Proteínas de Almacenamiento de Semillas/inmunologíaRESUMEN
Edible plant seeds provide a relatively inexpensive source of protein and make up a large part of nutrients for humans. Plant seeds accumulate storage proteins during seed development. Seed storage proteins act as a reserve of nutrition for seed germination and seedling growth. However, seed storage proteins may be allergenic, and the prevalence of food allergy has increased rapidly in recent years. The 11S globulins account for a significant number of known major food allergens. They are of interest to the public and the agricultural industry because of food safety concerns and the need for crop enhancement. We sought to determine the crystal structure of Cor a 9, the 11 S storage protein of hazelnut and a food allergen. The structure was refined to 1.92 Å, and the R and Rfree for the refined structure are 17.6% and 22.5%, respectively. The structure of Cor a 9 showed a hetero hexamer of an 11S seed storage protein for the first time. The hexamer was two trimers associated back-to-back. Two long alpha helixes at the C-terminal end of the acidic domain of one of the Cor a 9 isoforms lay at the trimer-trimer interface's groove. These data provided much-needed information about the allergenicity of the 11S seed proteins. The information may also facilitate a better understanding of the folding and transportation of 11S seed storage proteins.
Asunto(s)
Corylus , Proteínas de Almacenamiento de Semillas , Corylus/química , Corylus/metabolismo , Proteínas de Almacenamiento de Semillas/química , Proteínas de Almacenamiento de Semillas/metabolismo , Cristalografía por Rayos X , Semillas/metabolismo , Semillas/química , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Globulinas/química , Globulinas/metabolismo , Secuencia de Aminoácidos , Multimerización de Proteína , Modelos MolecularesRESUMEN
Liposomes were modified with different proportions of ß-conglycinin (7S) and glycinin (11S) to form Lip-7S and Lip-11S. The morphology, interaction and in vitro simulated digestion of liposomes were studied. The particle size of Lip-7S was smaller than that of Lip-11S. When the values of Lip-7S and Lip-11S were 1:1 and 1:0.75, respectively, the ζ-potential had the maximum absolute value and the dispersion of the system was good. The results of multispectral analysis showed that hydrogen-bond and hydrophobic interaction dominated protein-modified liposomes, the protein structure adsorbed on the surface of liposomes changed, the content of α-helix decreased, and the structure of protein-modified liposomes became denser. The surface hydrophobicity and micropolarity of liposomes decreased with the increase of protein ratio, and tended to be stable after Lip-7S (1:1) and Lip-11S (1:0.75). Differential scanning calorimetry showed that Lip-7S had higher phase transition temperature (≥170.5 °C) and better rigid structure. During simulated digestion, Lip-7S (22.5 %) released less Morin than Lip (40.6 %) and Lip-11S (26.2 %), and effectively delayed the release of FFAs. The environmental stability of liposomes was effectively improved by protein modification, and 7S had better modification effect than 11S. This provides a theoretical basis for 7S and 11S modified liposomes, and also provides a data reference for searching for new materials for stabilization of liposomes.
Asunto(s)
Antígenos de Plantas , Globulinas , Liposomas , Proteínas de Almacenamiento de Semillas , Proteínas de Soja , Globulinas/química , Proteínas de Almacenamiento de Semillas/química , Proteínas de Soja/química , Liposomas/química , Antígenos de Plantas/química , Interacciones Hidrofóbicas e Hidrofílicas , Digestión , Tamaño de la Partícula , Enlace de HidrógenoRESUMEN
BACKGROUND: With the increasing popularity of plant protein-based diets, soy proteins are favored as the most important source of plant protein worldwide. However, potential food allergy risks limit their use in the food industry. This work aims to reveal the mechanism of ß-conglycinin-induced food allergy, and to explore the regulatory mechanism of heat treatment and high hydrostatic pressure (HHP) treatment in a BALB/c mouse model. RESULTS: Our results showed that oral administration of ß-conglycinin induced severe allergic symptoms in BALB/c mice, but these symptoms were effectively alleviated through heat treatment and HHP treatment. Moreover, ß-conglycinin stimulated lymphocyte proliferation and differentiation; a large number of cytokines interleukin (IL)-4, IL-5, IL-10, IL-12 and IL-13 were released and interferon γ secretion was inhibited, which disrupted the Th1/Th2 immune balance and promoted the differentiation and proliferation of naive T cells into Th2-type cells. CONCLUSION: Heat/non-heat treatment altered the conformation of soybean protein, which significantly reduced allergic reactions in mice. This regulatory mechanism may be associated with Th1/Th2 immune balance. Our results provide data support for understanding the changes in allergenicity of soybean protein within the food industry. © 2024 Society of Chemical Industry.
Asunto(s)
Antígenos de Plantas , Modelos Animales de Enfermedad , Hipersensibilidad a los Alimentos , Globulinas , Calor , Ratones Endogámicos BALB C , Proteínas de Almacenamiento de Semillas , Proteínas de Soja , Células TH1 , Células Th2 , Animales , Hipersensibilidad a los Alimentos/inmunología , Globulinas/química , Globulinas/inmunología , Globulinas/administración & dosificación , Proteínas de Soja/química , Proteínas de Soja/inmunología , Proteínas de Almacenamiento de Semillas/química , Proteínas de Almacenamiento de Semillas/inmunología , Proteínas de Almacenamiento de Semillas/administración & dosificación , Ratones , Antígenos de Plantas/inmunología , Antígenos de Plantas/química , Células TH1/inmunología , Células TH1/efectos de los fármacos , Células Th2/inmunología , Femenino , Humanos , Balance Th1 - Th2/efectos de los fármacos , Citocinas/inmunología , Citocinas/metabolismo , Glycine max/químicaRESUMEN
The pH-shifting process is an effective encapsulation method, and it is typically performed at extreme alkaline pH, which severely limits the application. In this study, we found that there were critical pH for the unfolding proteins during pH-shifting from 7 to 12, and upon the critical pH, physiochemical characteristics of protein greatly changed, leading to a sharp increase of encapsulation of hydrophobic actives. Firstly, the critical pH for ß-conglycinin (7S) or Glycinin (11S) unfolding was determined by multispectral technology. The critical pH for 7S and 11S were 10.5 and 10.3, respectively. The encapsulation efficiency (EE) obtained by ß-conglycinin-curcumin nanocomposite (7S-Cur) (88.80 %) and Glycinin-curcumin nanocomposite (11S-Cur) (88.38 %) at critical pH was significantly higher than that obtained by pH 7 (7S-Cur = 16.66 % and 11S-Cur = 15.78 %), and both values were close to EE obtained by at 12 (7S-Cur = 95.16 % and 11S-Cur = 94.63 %). The large-scale application of hydrophobic functional compounds will be enhanced by the experimental results.
Asunto(s)
Curcumina , Globulinas , Proteínas de Soja/química , Antígenos de Plantas/química , Proteínas de Almacenamiento de Semillas/química , Globulinas/química , Interacciones Hidrofóbicas e Hidrofílicas , Concentración de Iones de HidrógenoRESUMEN
The interaction mechanism between nanoliposomes (NL) and a soybean protein isolate (SPI) was investigated via the complexation between NL and two major components of SPI, i.e., ß-conglycinin (7S) and glycinin (11S). The endogenous fluorescence emissions of 7S and 11S were statically quenched after complexation with NL, and the polarity of the SPI fluorophore increased. The interaction between NL and SPI was exothermic and spontaneous, 7S/11S secondary structures were altered, and more hydrophobic groups were exposed on protein surfaces. Moreover, the NL-SPI complex had a large zeta potential to attain system stability. Hydrophobic forces and hydrogen bonds played vital roles in the interaction between NL and 7S/11S, and a salt bridge was also involved in the NL-11S interaction. The binding characteristics between NL and 7S/11S were chiefly governed by the protein characteristics, such as amino acid composition, surface hydrophobicity, and advanced structure. These findings could deepen the understanding of the interaction mechanism between NL and SPI.
Asunto(s)
Globulinas , Proteínas de Soja , Proteínas de Soja/química , Globulinas/química , Antígenos de Plantas/química , Proteínas de Almacenamiento de Semillas/química , Glycine max/químicaRESUMEN
The overall objective of this work is the evaluation of different competitive aptamer assays based on inductively coupled plasma mass spectrometry (ICP-MS) detection for the determination of ß-conglutin (food protein allergen from lupin) in flour samples. To this end, two competitive aptamer assay schemes were developed using either thiolated aptamers chemisorbed onto gold nanoparticles (AuNPs) or biotinylated aptamers linked to streptavidin-AuNPs. The influence of ICP-MS detection mode (i.e., conventional vs single particle) on assay performance was explored. In the case of the thiolated aptamer, the limit of detection (LoD) obtained using the single particle mode was improved 2-fold as compared to the LoD provided by the conventional mode. With regards to the biotinylated aptamer, the use of the conventional mode provided a 5-fold improvement of LoD as compared to that obtained for the single particle one. Using the optimized conditions, the best LoD of 2 pM was obtained with the biotinylated aptamer operating with conventional ICP-MS detection. When compared to previous reports using the same aptamer in a competitive assay, the developed method significantly improved the LoD by at least an order of magnitude. Different flour samples containing lupin were successfully analyzed according to European Conformity guidelines for the analysis of food contaminants.
Asunto(s)
Aptámeros de Nucleótidos , Lupinus , Nanopartículas del Metal , Oro/química , Aptámeros de Nucleótidos/química , Nanopartículas del Metal/química , Proteínas de Almacenamiento de Semillas/análisis , Proteínas de Almacenamiento de Semillas/química , Alérgenos/análisis , Lupinus/química , Espectrometría de MasasRESUMEN
Tyrosinase-catalyzed synthesis of soy 7S/11S-phlorizin conjugates was performed, and the reaction sites, conformation alterations and functional properties of complexes were evaluated using proteomic, in combination with multispectral technologies. Phlorizin was conjugated to 7S/11S primarily via residues of Lys, Cys, His and Arg residues. The phlorizin binding equivalents and decreased contents of free and total sulfhydryl groups and free amino groups confirmed the covalent interaction in the 7S/11S-phlorizin complexes. Conjugation with phlorizin promoted the conversion of α-helix to ß-sheet and ß-turn, with simultaneous transformation of the microenvironments around Trp and Tyr residues to hydrophilic and hydrophobic microenvironments, respectively, and lowering of the surface hydrophobicity of 7S/11S. The DPPH and ABTS radical scavenging abilities and α-glucosidase inhibitory activities of 7S/11S were increased by three-, two- and three-fold after the covalent binding of phlorizin. The study provided an ideal tyrosinase-catalyzed approach to fabricate custom-tailored nutritional soy protein-polyphenol products.
Asunto(s)
Globulinas , Proteínas de Soja , Proteínas de Soja/química , Globulinas/química , Proteínas de Almacenamiento de Semillas/química , Monofenol Monooxigenasa/metabolismo , Florizina , Antígenos de Plantas/química , Proteómica , Sitios de Unión , CatálisisRESUMEN
To reveal the nature of thermal aggregation of soybean protein at subunit level, structure and physicochemical properties of αα'- and ß-subunits isolated from ß-conglycinin, acidic polypeptide, and basic polypeptide from glycinin, as well as ß-conglycinin and glycinin, were characterized before and after heat treatment. The transmission electron microscopy (TEM) images showed that ß-conglycinin, αα'-subunits and acidic polypeptide formed regular thermal aggregates, which exhibited high solubility, high ζ-potential value, and small particle size. While glycinin, ß-subunit, and basic polypeptide aggregated to insoluble clusters with large particle size distribution. The results of size exclusion chromatography and non-reducing electrophoresis showed that the disulfide bond was the important force in stabilizing the protein conformation of thermal aggregates in ß-conglycinin, glycinin, and their isolated subunits/polypeptides but ß-subunit. The results of surface hydrophobicity and intrinsic fluorescence spectra showed that the thermal aggregations of ß-subunit and basic polypeptide were mainly driven by hydrophobic interactions.
Asunto(s)
Globulinas , Proteínas de Soja , Proteínas de Soja/química , Calor , Globulinas/química , Proteínas de Almacenamiento de Semillas/química , Antígenos de Plantas/química , Péptidos , Interacciones Hidrofóbicas e Hidrofílicas , Conformación Proteica , Glycine max/químicaRESUMEN
Sodium alginate (SA), α1 â 4 linked copolymer of ß-d-mannuronic acid (M) and α-L guluronic acid (G) forms two homopolymeric fractions (MM and GG) and a heteropolymeric fraction (MG). The main components of soybean protein isolate are ß-conglycinin (7S) and glycinin (11S). However, accurate structural analyses of the 7S/11S and MM/MG/GG complexes are lacking. The complexation mechanism, structure, and functional properties of the complexes of 7S/11S with SA blocks was investigated at pH 4. The number of intermolecular hydrogen bonds exceeded that of the intramolecular hydrogen bonds. Secondary and tertiary structures and molecular weights of the complexes were significantly different from those of 7S/11S. The crystalline structure transformed to an amorphous structure, and the complexes underwent fluorescence quenching. Complexes 11S-MM and 11S-MG exhibited good emulsifying properties of 37.88 % and 38.13 %, respectively; 7S-GG and 7S-MM exhibited excellent surface hydrophobicity and emulsifying properties; and 11S-MM, 11S-GG, and 11S-MG exhibited excellent thermal stability.
Asunto(s)
Globulinas , Proteínas de Soja , Proteínas de Soja/química , Alginatos , Globulinas/química , Proteínas de Almacenamiento de Semillas/química , Antígenos de Plantas/química , Glycine max/químicaRESUMEN
Lipid binding has been proposed to represent a functional property of many allergenic proteins. This study investigated the formation, characterization, and antigenicity of lecithin-ß-conglycinin complexes. The results indicate that lecithin was combined with ß-conglycinin via static quenching and primarily driven by hydrogen bonds and van der Waals forces. In addition, heat treatment reduced the antigenicity of complexes, as evidenced by changes in molecular weight and secondary and tertiary structures. It revealed that large aggregates developed and more hydrophobic regions were exposed for complexes after heat treatment, as well as a decrease in the ß-sheet contents and an increase in the ß-turn and random coil contents. Furthermore, the average particle size of the complexes increased with increased temperature treatment, and the morphology of the complexes exhibited an amorphous polymer. These findings shedlight on the interaction between lecithin and ß-conglycinin and help us understand the role of lecithin in allergic reactions.
Asunto(s)
Globulinas , Lecitinas , Proteínas de Soja/química , Antígenos de Plantas/química , Proteínas de Almacenamiento de Semillas/química , Globulinas/químicaRESUMEN
This study investigated the effect of lactic-acid-bacteria fermentation on the microstructure and gastrointestinal digestibility of soy proteins using a digestomics approach. Fermented soy protein isolates (FSPIs) under varied fermentation-terminal pH demonstrated a colloidal solution (FSPI-7.0/6.0) or yogurt-like curd (FSPI-5.0/4.0) state. Cryo-electron microscopy figures demonstrated the loosely stacked layer of FSPI-7.0/6.0 samples, whereas a denser gel network was observed for FSPI-5.0/4.0 samples. Molecular interactions shifted from dominant ionic bonds to hydrophobic forces and disulfide bonds. The gastric/intestinal digestion demonstrated that the curd samples afforded a significantly low particle size and high-soluble protein and peptide contents in the medium and late digestive phases. A peptidomics study showed that the FSPI-6.0 digestate at early intestinal digestion had a high peptidome abundance, whereas FSPI curd digestates (FSPI-5.0/4.0) elicited a postponed but more extensive promotion during medium and late digestion. Glycinin G2/G4 and ß-conglycinin α/α' subunits were the major subunits promoted by FSPI-curds. The spatial structures of glycinin G2 and ß-conglycinin α subunits demonstrated variations located in seven regions. Glycinin G2 region 6 (A349-K356) and ß-conglycinin α subunit region 7 (E556-E575), which were located at the interior of the 3D structure, were the key regions contributing to discrepancies at the late stage.
Asunto(s)
Globulinas , Lactobacillales , Proteínas de Soja/química , Lactobacillales/metabolismo , Microscopía por Crioelectrón , Globulinas/química , Proteínas de Almacenamiento de Semillas/química , Antígenos de Plantas/química , Suplementos Dietéticos , Tracto Gastrointestinal/metabolismo , Glycine max/metabolismoRESUMEN
This present work underlines the effect of pH-shifting at pH 2 and pH 12 individually or combined with ultrasound treatment to modify the molecular structure of ß-conglycinin (7S) on its emulsifying properties and stability. Fourier transform infrared (FTIR) spectroscopy and intrinsic fluorescence spectroscopy showed that pH-shifting improves the molecular structure of 7S, while ultrasound further promotes structural changes. In particular, the pH-shifting at pH 12 combined with ultrasound treatment (U-7S-12) resulted in more significant changes than the pH-shifting at pH 2 combined with ultrasound (U-7S-2). U-7S-12 showed a significant reduction in protein particle size from 152 to 34.77 nm and a relatively smooth protein surface compared to 7S. The protein had the highest surface hydrophobicity and flexibility at 81,560.0 and 0.45, respectively, and the free sulfhydryl content from 1.57 to 2.02 µmol/g. In addition, we characterized the emulsions prepared after 7S treatment. The single or combined treatment increased the interfacial protein adsorption of the samples, which showed lower viscosity and shear stress compared to 7S. The U-7S-12 emulsion exhibited the highest emulsifying properties and was more stable than other emulsions under creaming, heating, and freeze-thaw conditions. In summary, the concerted action of pH-shifting and ultrasound can modify the structure, and combined alkaline pH-shifting and ultrasound treatment can further improve the emulsifying properties and stability of 7S.
Asunto(s)
Globulinas , Globulinas/química , Proteínas de Almacenamiento de Semillas/química , Proteínas de Soja/química , Emulsiones/química , Concentración de Iones de HidrógenoRESUMEN
Previous studies have found that soybean protein, especially soybean 7S protein (ß-conglycinin), exhibits digestion resistance, but the mechanism of digestion resistance and its implications for human health are still unclear. Here, we show that the extracted soybean 7S protein contains both oligomer globulins and amyloid aggregates, while the gastric digested soybean 7S protein only contains amyloid aggregates and thus exhibits digestion resistance. An animal experiment shows that un-digestible soybean 7S protein effectively prevents aspirin-induced acute gastric mucosa damage. The impacts of un-digestible soybean 7S protein on gastric mucus barrier properties are investigated using quartz crystal microbalance with dissipation (QCM-D), Langmuir monolayer, and multiple particle tracking (MPT). Results show that these un-digestible protein aggregates can penetrate into gastric mucus, increase the viscosity and compactness of the mucin layer, and reinforce the gastric mucus barrier properties. The findings are helpful to understand that high consumption of non-fermented soybean foods is associated with a decreased risk of gastric cancer.
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Mucosa Gástrica , Globulinas , Proteínas de Almacenamiento de Semillas , Proteínas de Soja , Animales , Antígenos de Plantas/química , Aspirina/efectos adversos , Digestión , Mucosa Gástrica/efectos de los fármacos , Mucosa Gástrica/patología , Globulinas/química , Moco/química , Tecnicas de Microbalanza del Cristal de Cuarzo , Proteínas de Almacenamiento de Semillas/química , Proteínas de Soja/química , Glycine max/químicaRESUMEN
The structural properties, interfacial behavior, and emulsifying ability of ultrasound-treated pea protein isolate (PPI) and the legumin (11S) and vicilin (7S) globulin fractions prepared with a salt-solubilization procedure were investigated. Of the three protein groups, PPI was strongly responsive to ultrasound perturbation (20 kHz, 57-60 W·cm-2) showing the greatest solubility increase, particle size reduction, structure destabilization, and conformational change. Similar but less remarkable effects were observed on 11S globulins; 7S proteins, already highly soluble (>99%), were generally less sensitive to ultrasound. The ultrasound treatment significantly improved emulsifying activity, which resulted in greater emulsifying capacity and stronger interfacial adsorption for all protein samples. PPI exhibited the higher activity increase (70.8%) compared to approximately 30% for 11S and 7S. For both control and ultrasound treated proteins, the emulsifying capacity was in the order of 7S > 11S > PPI, inversely related to the trend of protein loading at the interface, indicating efficiency differences. The latter was attributed to emulsion clusters formed through protein-protein interaction in PPI and 11S emulsions which were visibly absent in 7S emulsions.
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Fabaceae , Globulinas , Proteínas de Guisantes , Emulsiones , Fabaceae/química , Globulinas/química , Pisum sativum/química , Proteínas de Almacenamiento de Semillas/química , VerdurasRESUMEN
The binding mechanisms between soy ß-conglycinin/glycinin and (-)-epigallocatechin-3-gallate (EGCG) were evaluated using multi-spectral techniques and molecular modeling. Additionally, the emulsifying properties of ß-conglycinin/glycinin were investigated in their interactions with EGCG. Fluorescence analysis revealed that the quenching of ß-conglycinin/glycinin by EGCG was static quenching. Specifically, EGCG to ß-conglycinin/glycinin resulted in the conformation changes of the Trp and Tyr residues, around which the polarity toward more hydrophilic. The dominated binding between ß-conglycinin and EGCG was hydrogen bonding, whereas was mainly hydrophobic force between glycinin and EGCG. Such affinity induced a more organized protein confirmation with decreased random coil and increased α-helix and ß-structures. The docking data indicated the better affinity between glycinin and EGCG, compared to ß-conglycinin. The emulsifying ability and capacity of ß-conglycinin were enhanced with involvement EGCG, however no effect was found for glycinin. Our findings deliver insights in understanding of the interaction mechanisms between ß-conglycinin/glycinin and EGCG.