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Arabinogalactan exhibits many biological activities, which is the candidate for functional food ingredients. However, there is limited research on the arabinogalactan from Moringa Oleifera leaf, and its structure needs to be more accurately characterized. This study investigated structural characteristics and immunomodulatory activity of a high-purity polysaccharide from Moringa oleifera leaf (i.e. MOLP-PE) to further explore arabinogalactan from Moringa Oleifera Lam. leaf and its potential application area. The results showed that MOLP-PE was a unique type II arabinogalactan: the main chain consisted of â 3, 4)-α-D-Galp-(1â, â3)-ß-D-Galp-(1â and â2, 4)-ß-D-Rhap-(1â, with branches at the C-4 position of â3, 4)-α-D-Galp-(1â and â2, 4)-ß-D-Rhap-(1â, consisting of â5)-α-L-Araf-(1â, â3)-α-L-Araf-(1â, â6)-ß-D-Galp-(1â and â4)-ß-D-GalpA-(1â. Compared with arabinogalactan from larch, galactan and arabinan, MOLP-PE exhibited stronger ability in stimulating proliferation, phagocytosis and cytokines release of macrophages and bound with Toll-like receptor 4 closer via more binding sites, which might be due to its higher contents of 1,3-linked-Galp and 1,5-linked-Araf. These findings elucidated that MOLP-PE, as type II arabinogalactan with a unique structure, could be exploited as an immunomodulatory food ingredient.
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Milk casein is regarded as source to release potential sleep-enhancing peptides. Although various casein hydrolysates exhibited sleep-enhancing activity, the underlying reason remains unclear. This study firstly revealed the structural features of potential sleep-enhancing peptides from casein hydrolysates analyzed through peptidomics and multivariate analysis. Additionally, a random forest model and a potential Tyr-based peptide library were established, and then those peptides were quantified to facilitate rapidly-screening. Our findings indicated that YP-, YI/L, and YQ-type peptides with 4-10 amino acids contributed more to higher sleep-enhancing activity of casein hydrolysates, due to their crucial structural features and abundant numbers. Furthermore, three novel strong sleep-enhancing peptides, YQKFPQY, YPFPGPIPN, and YIPIQY were screened, and their activities were validated in vivo. Molecular docking results elucidated the importance of the YP/I/L/Q- structure at the N-terminus of casein peptides in forming crucial hydrogen bond and π-alkyl interactions with His-102 and Asn-60, respectively in the GABAA receptor for activation.
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Our previous study identified round scad neuroprotective peptides with different characteristics. However, the intrinsic relationship between their structure and bioactivity, as well as their bioavailability, remains unclear. The aim of this study is to elucidate the bioavailability of these peptides and their structure-activity relationship against neuroinflammation. Results showed that the SR and WCP peptides were resistant to gastrointestinal digestion. Additionally, peptides SR, WCP, and WCPF could transport Caco-2 monolayers as intact peptides. The permeability coefficients (Papp) of SR, WCP, and WCPF in Caco-2 monolayer were (1.53 ± 0.01) × 10-5, (2.12 ± 0.01) × 10-5, and (8.86 ± 0.03) × 10-7 cm/s, respectively. Peptides SR, WCP, and WCPF, as promising inhibitors of JAK2 and STAT3, could attenuate the levels of pro-inflammatory cytokines and regulate the NFκB and JAK2/STAT3 signaling pathway in LPS-treated BV-2 cells. WCPF exerted the highest anti-inflammatory activity. Moreover, bioinformatics, molecular docking, and quantum chemistry studies indicated that the bioactivity of SR was attributed to Arg, whereas those of WCP and WCPF were attributed to Trp. This study supports the application of round-scad peptides and deepens the understanding of the structure-activity relationship of neuroprotective peptides.
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Antiinflamatorios , Janus Quinasa 2 , Péptidos , Humanos , Relación Estructura-Actividad , Péptidos/química , Péptidos/farmacología , Células CACO-2 , Janus Quinasa 2/metabolismo , Janus Quinasa 2/química , Antiinflamatorios/química , Antiinflamatorios/farmacología , Fármacos Neuroprotectores/química , Fármacos Neuroprotectores/farmacología , Animales , Ratones , Proteínas de Peces/química , Proteínas de Peces/farmacología , Factor de Transcripción STAT3/metabolismo , Factor de Transcripción STAT3/química , Factor de Transcripción STAT3/genética , Simulación del Acoplamiento Molecular , FN-kappa B/metabolismo , FN-kappa B/genética , FN-kappa B/químicaRESUMEN
In this study, an acidic polysaccharide (FVP-7 A) was isolated from Fucus vesiculosus by DEAE-Sepharose™ fast flow. The chemical composition, glycosidic bonds and in vitro fecal fermentation characteristics of FVP-7 A were studied. Results shown that FVP-7 A was a homogenous polysaccharide with average molecular weight of 30.94 kDa. Combined with FT-IR, monosaccharide composition, methylation and NMR analysis, the glycosidic bonds of FVP-7 A mainly composed of â4)-ß-D-Manp-(1â, â3)-α-L-Fucp-(1â, α-D-Manp-(1â, â3)-ß-D-Manp-(1 â and â4,6)-α-D-Manp-(1â. The zeta potential and atomic force microscopy images indicated that FVP-7 A could exist stably as a single chain-like structure in dilute solution. After gut fermentation, FVP-7 A was utilized and promoted multiple short-chain fatty acids production, especially acetic acid, butyric acid and valeric acid. For prebiotics, FVP-7 A significantly increased the relative abundance of short-chain fatty acids producing bacteria such as Bacteroides, Lachnospira, Faecalibacterium, Ruminococcus, Oscillospira and Dialister, and inhiited the growth of the harmful bacteria Shigella. These results indicated that FVP-7 A could be used as a potential dietary supplement to improve intestinal health.
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Fermentación , Fucus , Microbioma Gastrointestinal , Polisacáridos , Polisacáridos/química , Polisacáridos/farmacología , Humanos , Fucus/química , Ácidos Grasos Volátiles/metabolismo , Peso Molecular , Prebióticos , Heces/microbiología , Monosacáridos/análisis , MetilaciónRESUMEN
Poor stability during gastrointestinal digestion is a major challenge for the applications of protein-based nanoparticles as oral delivery systems. In this work, genipin was used to crosslink the partially enzymatic hydrolyzed soy protein nanoparticles, aiming to improve their performance in gastrointestinal tract as delivery carrier. Results showed that the obtained genipin-crosslinked soy protein nanoparticles (GSPNPs) were still spherically monodisperse with a diameter around 60 nm. Encapsulation with GSPNPs significantly improved the solubility of curcumin (Cur) and its stability against UV light as well as long-term storage. Compared to those un-crosslinked nanoparticles, particles crosslinked by genipin had a more compact structure less sensitive to ionic effect and digestive enzymes, showing enhanced digestion stability. The well-maintained nanoparticulate structure of GSPNPs further contributed to the enhanced bioaccessibility and facilitated absorption by epithelial cells. Furthermore, in vivo experiment on rats showed that Cur encapsulated in GSPNPs exhibited a slowed down and sustained absorption manner with an 8.11-fold improvement in its bioavailability. These suggested that GSPNPs could be a promising nanocarrier to enhance the bioavailability of functional factors.
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Disponibilidad Biológica , Curcumina , Iridoides , Nanopartículas , Proteínas de Soja , Curcumina/química , Curcumina/farmacocinética , Curcumina/farmacología , Nanopartículas/química , Iridoides/química , Animales , Ratas , Proteínas de Soja/química , Tracto Gastrointestinal/metabolismo , Tracto Gastrointestinal/efectos de los fármacos , Humanos , Estabilidad de Medicamentos , Digestión/efectos de los fármacos , Portadores de Fármacos/química , Tamaño de la Partícula , Solubilidad , Reactivos de Enlaces Cruzados/química , Ratas Sprague-Dawley , Masculino , Células CACO-2RESUMEN
Alcoholic liver injury has become a leading threat to human health, with complicated pathogenesis and limited therapeutic options. Our previous study showed that Musculus senhousei peptides (MSPs) exhibit protective potential against early-stage alcoholic liver injury, although the underlying mechanism is not yet clear. In this study, histopathological analysis, mRNA abundance of injury-associated biomarkers, the gut microbiota, and faecal metabolome were evaluated using a mouse model subjected to acute alcohol exposure, aiming to identify the mechanism by which MSP can alleviate alcoholic hepatotoxicity. The results showed that MSP intervention significantly ameliorated symptoms of liver injury (suppressed serum ALT increment, hepatic lipid accumulation, and neutrophil infiltration in liver tissue), and reversed the abnormal mRNA abundance of biomarkers associated with oxidative stress (iNOS), inflammation (TNF-α, IL-1ß, MCP-1, TNF-R1, and TLR4), and apoptosis (Bax and Casp. 3) in the liver. Moreover, MSP improved intestinal barrier function by increasing the expression of tight junction proteins (Claudin-1 and Claudin-3). Further analysis of faecal microbiota and metabolome revealed that MSP promoted the growth of tryptophan-metabolizing bacteria (Clostridiales, Alistipes, and Odoribacter), leading to increased production of indole derivatives (indole-3-lactic acid and N-acetyltryptophan). These results suggested that MSPs may alleviate alcohol-induced liver injury targeting the gut-liver axis, and could be an effective option for the prevention of alcoholic liver injury.
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Microbioma Gastrointestinal , Hepatopatías Alcohólicas , Hígado , Ratones Endogámicos C57BL , Animales , Ratones , Microbioma Gastrointestinal/efectos de los fármacos , Masculino , Hepatopatías Alcohólicas/tratamiento farmacológico , Hepatopatías Alcohólicas/metabolismo , Hígado/metabolismo , Hígado/efectos de los fármacos , Péptidos/farmacología , Estrés Oxidativo/efectos de los fármacos , Modelos Animales de EnfermedadRESUMEN
Alcohol intake has become one of the leading risks to human health and wellness, among which acute and/or chronic alcohol-induced liver injury is a leading threaten, with few therapeutic options other than abstinence. In recent years, studies suggested that certain bioactive peptides from food sources could represent natural and safe alternatives for the prevention of alcoholic liver injury. Hence, this chapter focus on the advanced research on bioactive peptides exerting hepatoprotective activity against alcoholic liver injury. The main sources of protein, strategies for the preparation of hepatoprotective hydrolysates and peptides, underlying mechanisms of peptides on hepatoprotection, and possible structure-activity relationship between peptides and hepatoprotective activity were summarized and discussed, aiming to give a systematic insight into the research progress of hepatoprotective peptides. However, more efforts would be needed to give a clearer insight into the underlying mechanisms and structure-activity relationship before using hepatoprotective peptides as functional food ingredients or dietary supplements.
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Hepatopatías Alcohólicas , Péptidos , Humanos , Hepatopatías Alcohólicas/prevención & control , Péptidos/farmacología , Péptidos/química , Sustancias Protectoras/farmacología , Animales , Relación Estructura-Actividad , Hígado/efectos de los fármacosRESUMEN
Due to the difficulty in obtaining highly branched rhamnogalacturonan-I (RG-I) type pectin, the relationship between the extent of RG-I branching (EB) of pectin and prebiotic/immunomodulatory activity has not been systematically investigated. Moreover, it is only possible to establish a structure-activity relationship using pectin that is highly purified and accurately characterized. In this study, a homogeneous highly branched RG-I type pectin (LBP-P4, a final product) with dual proliferative effects on Bifidobacterium and macrophage was effectively purified for the first time using enzyme hydrolysis combined with ultrafiltration. The RG-I content and EB of LBP-P4 reached 97.32 and 77.12, respectively. Its two branches were composed of arabinan and arabinogalactan-II, containing â 5)-Araf-(1â, â3)-Araf-(1â, â3,6)-Galp-(1â and â6)-Galp-(1â residues). The structure-activity relationship analysis indicated that strong prebiotic/immunomodulatory activity of LBP-P4 was depended on its high EB, which was further confirmed by the molecular docking simulation between low/high branched pectin with ß-1,6-galactosidase, α-l-arabinanase, and Toll-like receptor 4 (TLR4).
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In this paper, effects of preheating-induced denaturation of proteins and oleosomes on protein structure and soymilk quality were studied. The protein in soybeans baked at 55 °C (B-55) and 85 °C (B-85) showed an increase of ß-sheet content by 3.2 % and a decrease of α-helix content by 3.3 %, indicating that proteins were gradually unfolded while oleosomes remained intact. The protein resisted thermal denaturation during secondary heating, and soymilks were stable as reflected by a small d3,2 (0.4 µm). However, raw soymilk from soybeans baked at 115 °C (B-115), steamed for 1 min (ST-1) and 5 min (ST-5) presented oleosomes destruction and lipids aggregates. The proteins were coated around the oil aggregates. The ß-turn content from soybeans steamed for 10 min (ST-10) increased by 9.5 %, with a dense network where the OBs were tightly wrapped, indicating the serious protein denaturation. As a result, the soymilks B-115 or steamed ones were unstable as evidenced by the serious protein aggregation and larger d3,2 (5.65-12.48 µm). Furthermore, the soymilks were graininess and the protein digestion was delayed due to the formation of insoluble protein aggregates. The flavor and early-stage lipid digestion of soymilk from steamed soybeans was improved owing to lipid release.
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Calor , Desnaturalización Proteica , Leche de Soja , Proteínas de Soja , Leche de Soja/química , Proteínas de Soja/química , Gotas Lipídicas/química , CulinariaRESUMEN
Recently, amino acid derivatives gradually gained attention, but studies on N-lactoyl-leucine (Lac-Leu) and N-lactoyl-isoleucine (Lac-Ile) are limited. This study aims to explore the contributions of Lac-Leu and Lac-Ile to soy sauce. Lac-Leu and Lac-Ile were synthesized via enzymatic synthesis method catalyzed by Tgase. The mixed solutions containing Lac-Leu were found to have greater taste improvement than those containing Lac-Ile. Sensory evaluation indicated the sour, bitter, and astringent taste of Lac-Leu in water as well as its kokumi, astringent, and umami-enhancing taste in MSG solution. The taste threshold and umami-enhancing threshold of Lac-Leu measured by TDA and cTDA, respectively, were 0.08 mg/mL and 0.16 mg/mL. Molecular docking of Lac-Leu and Lac-Ile with the kokumi receptor CaSR and the umami receptors T1R1 and T1R3 indicated that Lac-Leu had higher affinities with receptors than Lac-Ile. These findings demonstrated the underlying contribution Lac-Leu made to soy sauce, indicating its potential to improve the flavor quality of soy sauce.
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Aromatizantes , Leucina , Alimentos de Soja , Espectrometría de Masas en Tándem , Gusto , Alimentos de Soja/análisis , Humanos , Leucina/química , Leucina/análisis , Aromatizantes/química , Cromatografía Líquida de Alta Presión , Simulación del Acoplamiento Molecular , Adulto , Masculino , Femenino , Receptores Acoplados a Proteínas G/química , Receptores Acoplados a Proteínas G/metabolismo , Cromatografía Líquida con Espectrometría de MasasRESUMEN
Chronic stress is a major inducer of anxiety and insomnia. Milk casein has been studied for its stress-relieving effects. We previously prepared a casein hydrolysate (CP) rich in the sleep-enhancing peptide YPVEPF, and this study aims to systemically investigate the different protective effects of CP and casein on dysfunction and anxiety/insomnia behavior and its underlying mechanisms in chronically stressed mice. Behavioral results showed that CP ameliorated stress-induced insomnia and anxiety more effectively than milk casein, and this difference in amelioration was highly correlated with an increase in GABA, 5-HT, GABAA, 5-HT1A receptors, and BDNF and a decrease in IL-6 and NMDA receptors in stressed mice. Furthermore, CP restored these dysfunctions in the brain and colon by activating the HPA response, modulating the ERK/CREB-BDNF-TrκB signaling pathway, and alleviating inflammation. The abundant YPVEPF (1.20 ± 0.04%) and Tyr-based/Trp-containing peptides of CP may be the key reasons for its different effects compared to casein. Thus, this work revealed the main active structures of CP and provided a novel dietary intervention strategy for the prevention and treatment of chronic-stress-induced dysfunction and anxiety/insomnia behaviors.
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Ansiedad , Encéfalo , Caseínas , Trastornos del Inicio y del Mantenimiento del Sueño , Animales , Masculino , Ratones , Ansiedad/prevención & control , Conducta Animal/efectos de los fármacos , Encéfalo/metabolismo , Encéfalo/efectos de los fármacos , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Factor Neurotrófico Derivado del Encéfalo/genética , Caseínas/química , Caseínas/administración & dosificación , Sustancias Protectoras/administración & dosificación , Sustancias Protectoras/farmacología , Sustancias Protectoras/química , Trastornos del Inicio y del Mantenimiento del Sueño/tratamiento farmacológico , Trastornos del Inicio y del Mantenimiento del Sueño/metabolismo , Trastornos del Inicio y del Mantenimiento del Sueño/fisiopatología , Trastornos del Inicio y del Mantenimiento del Sueño/prevención & control , Estrés PsicológicoRESUMEN
In this study, we examined the possibility of using industrial microwave processing to enhance the gelling properties and reduce the starch digestibility of mung bean flour (MBF). MBF (12.6â¯% moisture) was microwaved at a power of 6â¯W/g to different final temperatures (100-130⯰C), and then its structural and functional properties were characterized. The microwave treatment had little impact on the crystalline structure or amylose content of the starch, but it roughened the starch granule surfaces and decreased the short-range ordered structure and degree of branching. In addition, the extent of mung bean protein denaturation caused by the microwave treatment depended on the final temperature. Slightly denaturing the proteins (100⯰C) did not affect the nature of the gels (protein phase dispersed in a starch phase) but the gel network became more compact. Moderately denaturing the proteins (110-120⯰C) led to more compact and homogeneous starch-protein double network gels. Excessive protein denaturation (130⯰C) caused the gel structure to become more heterogeneous. As a result, the facilitated tangles between starch chains by more linear starch molecules after debranching, and the protein network produced by moderate protein denaturation led to the formation of stronger gel and the improvement of plasticity during large deformation (large amplitude oscillatory shear-LAOS). Starch recrystallization, lipid complexion, and protein network retard starch digestion in the MBF gels. In conclusion, an industrial microwave treatment improved the gelling and digestive properties of MBF, and Lissajous curve has good adaptability in characterizing the viscoelasticity of gels under large deformations.
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Harina , Geles , Microondas , Desnaturalización Proteica , Reología , Almidón , Vigna , Almidón/química , Vigna/química , Geles/química , Proteínas de Plantas/química , Temperatura , Amilosa/químicaRESUMEN
Dipeptidyl peptidase-IV (DPP-IV) inhibiting peptides have attracted increased attention because of their possible beneficial effects on glycemic homeostasis. However, the structural basis underpinning their activities has not been well understood. This study combined computational and in vitro investigations to explore the structural basis of DPP-IV inhibitory peptides. We first superimposed the Xaa-Pro-type peptide-like structures from several crystal structures of DPP-IV ligand-protein complexes to analyze the recognition interactions of DPP-IV to peptides. Thereafter, a small set of Xaa-Pro-type peptides was designed to explore the effect of key interactions on inhibitory activity. The intramolecular interaction of Xaa-Pro-type peptides at the first and third positions from the N-terminus was pivotal to their inhibitory activities. Residue interactions between DPP-IV and residues of the peptides at the fourth and fifth positions of the N-terminus contributed significantly to the inhibitory effect of Xaa-Pro-type tetrapeptides and pentapeptides. Based on the interaction descriptors, quantitative structure-activity relationship (QSAR) studies with the DPP-IV inhibitory peptides resulted in valid models with high R2 values (0.90 for tripeptides; 0.91 for tetrapeptides and pentapeptides) and Q2 values (0.33 for tripeptides; 0.68 for tetrapeptides and pentapeptides). Taken together, the structural information on DPP-IV and peptides in this study facilitated the development of novel DPP-IV inhibitory peptides.
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Dipeptidil Peptidasa 4 , Inhibidores de la Dipeptidil-Peptidasa IV , Péptidos , Relación Estructura-Actividad Cuantitativa , Inhibidores de la Dipeptidil-Peptidasa IV/química , Dipeptidil Peptidasa 4/química , Dipeptidil Peptidasa 4/metabolismo , Péptidos/química , Péptidos/farmacología , Humanos , Secuencia de AminoácidosRESUMEN
Our previous study indicated that whey protein hydrolysate (WPH) showed effective anti-fatigue properties, but its regulatory mechanism on recovery from exercise in mice is unclear. In the present study, we divided the mice into control, WP, and WPH groups and allowed them to rest for 1 h and 24 h after exercise, respectively. The changes in muscle metabolites of mice in the recovery period were investigated using metabolomics techniques. The results showed that the WPH group significantly up-regulated 94 muscle metabolites within 1 h of rest, which was 1.96 and 2.61 times more than the control and WP groups, respectively. In detail, significant decreases in TCA cycle intermediates, lipid metabolites, and carbohydrate metabolites were observed in the control group during exercise recovery. In contrast, administration with WP and WPH enriched more amino acid metabolites within 1 h of rest, which might provide a more comprehensive metabolic environment for muscle repair. Moreover, the WPH group remarkably stimulated the enhancement of lipid, carbohydrate, and vitamin metabolites in the recovery period which might provide raw materials and energy for anabolic reactions. The result of the western blot further demonstrated that WPH could promote muscle repair via activating the Sestrin2/Akt/mTOR/S6K signaling pathway within 1 h of rest. These findings deepen our understanding of the regulatory mechanisms by WPH to promote muscle recovery and may serve as a reference for comprehensive assessments of protein supplements on exercise.
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Hidrolisados de Proteína , Suero Lácteo , Animales , Ratones , Proteína de Suero de Leche , Músculos , Carbohidratos , LípidosRESUMEN
Modernization of the traditional fermentation industry has been a major trend recently, such as the upgrading of fermentation containers. This study investigated the taste differences and their material basis of soy sauce fermented in tank and pond (SSFT and SSFP), and further explore the key influencing factors of taste. The intensities of umami, kokumi and sour taste in SSFT were weaker than SSFP, which were associated with 9 basic taste-active compounds, including acetic acid, lactic acid, propanedioic acid, citric acid, glutamic acid, alanine, tyrosine, d-galactose and erythritol. Moreover, 270 peptides and amino acid derivatives were potential compounds for taste difference, of which 78 % were more abundant in SSFP. Five bacterial genera (Kocuria, Tetragenococcus, Pediococcus, Staphylococcus, Weissella) and 4 fungal genera (Wickerhamiella, Millerozyma, Candida, Zygosaccharomyces) may be the functional core microbe for flavor differences in SSFT and SSFP. This study will provide theoretical value for quality improvement in the modern large-scale production of soy sauce.
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Lycium barbarum polysaccharide (LBP) is beneficial for elderly people, but its use is limited in geriatric foods due to the lack of comprehensive information on its preparation strategy and physical property. In this study, the low-ester rhamnogalacturonan-I (RG-I) type pectic polysaccharide-protein complexes with varying physicochemical properties, structural characteristics, proliferative activities on Bacteroides, and immune-enhancing activities on RAW 264.7 cells, were obtained by moderate-temperature acid extraction within adjustment of enzymatic and physical pretreatments. LBP prepared by moderate-temperature acid extraction, namely S1-A, showed the strongest immune-enhancing activity via increasing the phagocytosis capacity and NO release of RAW 264.7 cells by 23 % and 76 %, respectively. S1-A exhibited relatively high viscosity and calcium ion response characteristic with the application potential for thickened liquid foods for the elderly with dysphagia. LBP prepared by composite cellulase and pectinase pretreatment combined with moderate-temperature acid extraction, namely S1-M1, showed the strongest Bacteroides proliferative activity that was equivalent to 0.60-0.97 times of that of inulin. S1-M1 exhibited extremely low viscosity and strong tolerance to food nutrients with high processing applicability for fluid foods. This study provided crucial data for the preparation and application of LBP targeting gut microbiota disorders and immunosenescence for the development of geriatric foods.
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Bacteroides , Proliferación Celular , Ratones , Animales , Células RAW 264.7 , Bacteroides/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Medicamentos Herbarios Chinos/farmacología , Medicamentos Herbarios Chinos/química , Fagocitosis/efectos de los fármacos , Viscosidad , Factores Inmunológicos/farmacología , Factores Inmunológicos/química , Lycium/química , HumanosRESUMEN
Pectic polysaccharide is a bioactive ingredient in Chrysanthemum morifolium Ramat. 'Hangbaiju' (CMH), but the high proportion of HG domain limited its use as a prebiotic. In this study, hot water, cellulase-assisted, medium-temperature alkali, and deep eutectic solvent extraction strategies were firstly used to extract pectin from CMH (CMHP). CMHP obtained by cellulase-assisted extraction had high purity and strong ability to promote the proliferation of Bacteroides and mixed probiotics. However, 4 extraction strategies led to general high proportion of HG domain in CMHPs. To further enhance the dissolution and prebiotic potential of CMHP, pectinase was used alone and combined with cellulase. The key factor for the optimal extraction was enzymolysis by cellulase and pectinase in a mass ratio of 3:1 at 1 % (w/w) dosage. The optimal CMHP had high yield (15.15 %), high content of total sugar, and Bacteroides proliferative activity superior to inulin, which was probably due to the cooperation of complex enzyme on the destruction of cell wall and pectin structural modification for raised RG-I domain (80.30 %) with relatively high degree of branching and moderate HG domain. This study provided a green strategy for extraction of RG-I enriched prebiotic pectin from plants.
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Bacteroides , Chrysanthemum , Pectinas , Pectinas/química , Chrysanthemum/química , Proliferación Celular/efectos de los fármacos , Celulasa/química , Celulasa/metabolismo , Solubilidad , Poligalacturonasa/química , Poligalacturonasa/metabolismoRESUMEN
Genetic elements are foundational in synthetic biology serving as vital building blocks. They enable programming host cells for efficient production of valuable chemicals and recombinant proteins. The unfolded protein response (UPR) is a stress pathway in which the transcription factor Hac1 interacts with the upstream unfolded protein response element (UPRE) of the promoter to restore endoplasmic reticulum (ER) homeostasis. Here, we created a UPRE2 mutant (UPRE2m) library. Several rounds of screening identified many elements with enhanced responsiveness and a wider dynamic range. The most active element m84 displayed a response activity 3.72 times higher than the native UPRE2. These potent elements are versatile and compatible with various promoters. Overexpression of HAC1 enhanced stress signal transduction, expanding the signal output range of UPRE2m. Through molecular modeling and site-directed mutagenesis, we pinpointed the DNA-binding residue Lys60 in Hac1(Hac1-K60). We also confirmed that UPRE2m exhibited a higher binding affinity to Hac1. This shed light on the mechanism underlying the Hac1-UPRE2m interaction. Importantly, applying UPRE2m for target gene regulation effectively increased both recombinant protein production and natural product synthesis. These genetic elements provide valuable tools for dynamically regulating gene expression in yeast cell factories.
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Factores de Transcripción con Cremalleras de Leucina de Carácter Básico , Regulación Fúngica de la Expresión Génica , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Respuesta de Proteína Desplegada , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Respuesta de Proteína Desplegada/genética , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/genética , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismo , Regiones Promotoras Genéticas , Proteínas Represoras/genética , Proteínas Represoras/metabolismo , Retículo Endoplásmico/metabolismo , Transducción de Señal/genéticaRESUMEN
Short peptides have become the focus of recent research due to their variable bioactivities, good digestibility and wide existences in food-derived protein hydrolysates. However, due to the high complexity of the samples, identifying short peptides still remains a challenge. In this work, a tool, named PeposX-Exhaust, was developed for short peptide identification. Through validation with known peptides, PeposX-Exhaust identified all the submitted spectra and the accuracy rate reached 75.36%, and the adjusted accuracy rate further reached 98.55% when with top 5 candidates considered. Compared with other tools, the accuracy rate by PeposX-Exhaust was at least 70% higher than two database-search tools and 15% higher than the other two de novo-sequencing tools, respectively. For further application, the numbers of short peptides identified from soybean, walnut, collagen and bonito protein hydrolysates reached 1145, 628, 746 and 681, respectively. This fully demonstrated the superiority of the tool in short peptide identification.
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Curcumin (Cur) as a natural pigment and biological component, can be widely used in food and beverages. However, the water insolubility of Cur significantly limits its applications. In this study, we prepared a series of nanocrystals via ultrasound-assisted method to improve the solubility and availability of Cur. The results showed artemisia sphaerocephala krasch polysaccharide (ASKP), gum arabic (GA) and wheat protein (WP) were outstanding stabilizers for nanocryatals except traditional agent, poloxamer 188 (F68). The obtained curcumin nanocrystals (Cur-NC) displayed a rod-shaped, crystal- and nanosized structure, and extremely high loading capacity (more over 80 %, w/w). Compared with raw powder, Cur-NC greatly improved the water solubility and dispersibility, and the slow and complete release of Cur of Cur-NC also endowed them excellent antioxidant capacities even at 10 µg/mL. Importantly, as functional factor additive in beverages (e.g. water and emulsion), Cur-NC could increase the content of Cur to at least 600 µg/mL and retain a good stability. Overall, we provided an effective improvement method for the liposoluble active molecules (e.g. Cur) based on the nanocrystals, which not only tremendously enhanced its water solubility, but also strengthened its bioactivity. Notably, our findings broadened the application of water-insoluble compounds.