Egg White Peptides Research Articles

Potential Application of Egg White Peptides for Antioxidant Properties: Perspectives from Batch Stability and Network Pharmacology.

This study investigated the batch stability of egg white peptides (EWPs) during the enzymatic hydrolysis process, and confirmed the potential application of four crucial four peptides inoxidative damage repair. The results revealed that different batches of EWPs had good stability relating to antioxidant activity. With a similar sequence to confirmed antioxidant peptides, four EWPs (QMDDFE, WDDDPTD, DEPDPL, and FKDEDTQ) were identified withhigh repetition rates, and their potential to repair oxidative damage was investigated. Network pharmacology results showed that these four peptides could regulate the targets related to oxidative damage. Enrichment results demonstrated that these four peptides could influence the targets and pathways related to glutathione transferase activity (enrichment score: 148.0) and glutathione metabolism (p value: 9.22 × 10-10). This study could provide evidence for the batch stability of hydrolyzed prepared EWPs, and offer theoretical support for the development of antioxidant damage ingredients derived from foods.

Casein-quaternary chitosan complexes induced the soft assembly of egg white peptide and curcumin for ulcerative colitis alleviation

Soft assembly of peptide and curcumin (Cur) molecules enables functional integration by finding dynamic equilibrium states through non-covalent interactions. Herein, we developed two soft assembly systems, curcumin-egg white peptides (Cur-EWP) aggregations (AGs) and Cur-EWP-casein-quaternary chitosan (Cur-EWP-CA-QC) nanoparticles (NPs) to comparatively investigate their therapeutic effects on ulcerative colitis in mice and elucidate their underlying mechanism. Results revealed that Cur-EWP AGs, despite gastrointestinal tract instability, exhibited a propensity for swift accumulation within the colorectal region, enriching mucus-associated and short-chain fatty acid (SCAF)-producing bacteria, restoring the intestinal barrier damage. Whereas, Cur-EWP-CA-QC NPs, benefiting from their remarkable stability and exceptional mucosal adsorption properties, not only enhanced permeability of Cur and EWP in the small intestine to activate the immune response and boost tight junction protein expression but also, in their unabsorbed state, regulated the intestinal flora, exerting potent anti-inflammatory activity. Soft assembly of peptides and hydrophobic nutraceuticals could synergize biological activities to modulate chronic diseases.

Molecular Interactions Between Egg White Peptides and Giant Unilamellar Vesicle Membranes: Effect of Peptide Localization on Membrane Fluidity.

Bioactive peptides have been shown to affect cell membrane fluidity, which is an important indicator of the cell membrane structure and function. However, the underlying mechanism of egg white-derived bioactive peptide regulation of cell membrane fluidity has not been elucidated yet. The cell membrane fluidity was investigated by giant unilamellar vesicles in the present study. The results showed that peptides TCNW, ADWAK, ESIINF, VPIEGII, LVEEY, and WKLC connect to membranes through intermolecular interactions, such as hydrogen bonding and regulated membrane fluidity, in a concentration-dependent way. In addition, peptides prefer to localize in the hydrophobic core of the bilayers. This study provides a theoretical basis for analyzing the localization of egg white bioactive peptides in specific cell membrane regions and their influence on the cell membrane fluidity.

Egg White Peptides Accelerating the Wound Healing Process Through Modulating the PI3K-AKT Pathway: A Joint Analysis of Transcriptomic and Proteomic.

Wound healing is a multiphase process with a complex repair mechanism; trauma-repairing products with safety and high efficiency have a great market demand. Egg white peptides (EWP) have various physiological regulatory functions and have been proven efficient in ameliorating skin damage. However, their underlying regulation mechanism has not been revealed. This study further evaluated the EWP ameliorating mechanism by conducting a full-thickness skin wound model. Results demonstrated that EWP administration significantly inhibited the expression of pro-inflammatory and shortened the inflammatory phase. Besides, EWP can accelerate the secretion of growth factors (PDGF, VEGF, and TGF-β1) in skin tissue, significantly increasing the regeneration of granulation tissue and endothelium in the proliferation phase, thereby promoting wound healing. After 400 mg/kg EWP interventions for 13 days postoperation, the wound healing rate reached 90%. The combination of transcriptomic and proteomic analyses demonstrated the ameliorating efficiency effects of EWP on wound healing. EWP mainly participates in the functional network with the PI3K-AKT signaling pathway as the core to accelerate wound healing. These findings suggest a promising EWP-based strategy for accelerating wound healing.

Polysaccharide-addition order regulates sonicated egg white peptide stabilized nanoemulsions and β-carotene digestion in vitro

In this paper, the effects of the polysaccharide-addition order (before and after homogenisation) on the stability of nanoemulsion stabilised by sonicated egg white peptides and the in vitro digestive behaviour of loaded β-carotene were investigated. The pyrene fluorescence results showed that the concentration of micelles formed by flaxseed gum (FG) in complex with peptides was significantly higher than that of peach gum (PG). The order of polysaccharide-addition affected the emulsion properties and stability; adding polysaccharides before homogenisation led to protein bridging flocculation, low polysaccharide coverage and a higher interfacial adsorbed protein content of the emulsion. PG enhanced potential spatial resistance and electrostatic repulsion, effectively prevented emulsion flocculation and improved electrostatic stability. After homogenisation, FG was added to emulsions to improve environmental stability, including ionic, temperature and storage stability. Due to the viscosity of polysaccharides and the formed polysaccharide-protein-lipid aggregates, the increasing degree of bridging flocculation promoted the prominent of apparent viscosity, and the Gʹ and Gʹʹ exhibited a frequency-dependent increase. The polysaccharide type and mode changed the surface loading charge and droplet interface thickness, delayed the destruction of the droplet structure by protease, and slowed the release of β-carotene to form micelles. In this study, a stable emulsion system and an efficient emulsion transport system for bioactive substances were obtained by regulating polysaccharides adding order, which is significant for constructing an efficient food emulsion delivery system.

Egg white peptides administration in enhancing pathological immune response and regulating intestinal bacteria abundance: A new strategy for relieving young mice colitis

AbstractUlcerative colitis (UC) threatens teenagers’ health as it can damage the immune system and intestinal flora. The impact of egg white peptides (EWPs) on dextran sulfate sodium‐induced young colitis mice models was investigated. Findings suggested that EWPs improved colitis symptoms and modulated inflammatory factors in mice. EWPs treatment could enhance the abundance ratio of Firmicutes to Bacteroidetes, the relative abundances of Lactobacillus, and the concentrations of short‐chain fatty acids (SCFAs). According to Pearson correlation analysis, Bacteroides was favorably connected with IL‐6 and negatively correlated with acetic acid and total SCFAs. In conclusion, EWPs relieved young mice's UC symptoms by inhibiting the progression of colitis, regulating the inflammation response, and improving the imbalance of intestinal flora. The current study also supports using EWPs as a practical dietary resource for ameliorating UC.

Physicochemical and functional properties of egg white peptide powders under different storage conditions.

This study aims to evaluate the effects of different storage conditions (temperature and relative humidity) on the physicochemical and functional properties of egg white peptide powders (EWPPs). The samples (EWPPs) were stored for 28 d under four conditions (4°C, 50% RH; 4°C, 75% RH; 25°C, 50% RH; 25°C, 75% RH). Results showed that storage temperature and relative humidity had a significant effect on the physicochemical and functional properties of EWPPs. The contents of antioxidant amino acids such as histidine, tyrosine, tryptophan, and lysine were reduced significantly under different storage conditions, which resulted in the decrease of the antioxidant activity of EWPPs. Circular dichroism spectroscopy analysis indicated that the secondary structure of EWPPs changed from the regular structure to the irregular coiled structure during the storage. Additionally, the hydrophobic groups of the EWPPs originally embedded inside the molecules were exposed to the surface of the molecules during the storage, which led to an aggregation of EWPPs molecule and a decrease in solubility of EWPPs. The aggregation of EWPPs molecules resulted in a decrease in emulsification, emulsification stability, foaming ability and foaming stability of the EWPPs. Therefore, different storage conditions do have an impact on the physicochemical and functional properties of EWPPs. Lower temperature and humidity storing conditions were beneficial to retain the functional property of the EWPPs.

Immunomodulatory Function of Egg White Peptides in RAW264.7 Macrophage Cells and Immunosuppressive Mice Induced by Cyclophosphamide

Immunomodulatory Function of Egg White Peptides in RAW264.7 Macrophage Cells and Immunosuppressive Mice Induced by Cyclophosphamide

Diet supplementation with commercial enzymatically-hydrolyzed egg white peptides ameliorates the severity of allergy in a mouse model of egg white allergy.

Commercial spray-dried egg white (S-EW) is often used for oral immunotherapy (OIT). Peptifine® (PF), a commercial preparation of enzymatically-hydrolyzed egg white (EW) peptides, is considered safe OIT food. Here, we examined the therapeutic effect of PF or S-EW in a mouse model of EW allergy. Sensitized female BALB/c mice underwent 4-week OIT by supplementation of 19% casein diet with 1% PF (PF group) or S-EW (S-EW group), and non-supplementation of 20% casein diet (non-OIT group). Non-sensitized mice acted as the non-allergy group. Oral and intraperitoneal EW challenges were performed and allergic biomarkers were determined. Changes in rectal temperature after oral challenge were comparable in the allergy groups. However, after intraperitoneal challenge, rectal temperature decrease in the PF and S-EW groups was lower than in the non-OIT group. After 4 weeks, plasma levels of ovalbumin- and ovomucoid-specific antibodies were assessed; IgE levels in the PF and S-EW groups were lower than those in the non-OIT group. Interleukin-4 secretion after EW challenge was significantly lower in splenocyte cultures derived from PF and S-EW groups than in the non-OIT group. Furthermore, the percentage of CD4+ Foxp3+ splenocytes in the PF group was significantly higher than that in the non-OIT and S-EW groups. Oral gavage of 40 mg PF did not induce an allergic response in sensitized mice with EW. Diet supplementation with 1% PF mildly ameliorated the severity of allergy in mouse with EW allergy, indicating that PF is a safe OIT food.

Identification and Immunomodulatory Effect on Immunosuppressed Mice of Selenium-Enriched Peptides of Egg White

Selenium-enriched egg white peptides (Se-EWP) were prepared by pre-heat treatment and enzymatic hydrolysis in this study. In addition, their selenopeptide sequence identification and immunomodulatory effect were investigated. Results showed that the yield of Se-EWP obtained from alkaline-neutral protease treatment reached 76.90%, and peptides with a molecular weight of 200-1000 Da accounted for 98.33%. Four characteristic selenopeptides, including SeCys-Trp-Leu-Glu, Trp-Ser-SeCys, SeMet-Ala-Pro, and SeMet-Leu, were identified by HPLC-ESI-MS/MS, which were rich in hydrophobic and branched-chain amino acids. Se-EWP (750 mg/kg/d) could effectively retard the decrease of immune organ index in immunosuppressed mice induced by cyclophosphamide. Moreover, supplementation of Se-EWP could promote a higher content of Se in liver, the number of white blood cells, and the levels of serum cytokines (IL-6, IL-2, and TNF-α) as compared with EWP groups, indicating that Se-EWP could effectively alleviate immunosuppression induced by cyclophosphamide. These findings suggested that Se-EWP exhibited great potential as functional foods for immunomodulatory effect.

Aggregation of egg white peptides (EWP) induced by proanthocyanidins: A promising fabrication strategy for EWP emulsion

Egg-white peptides (EWP, <1 kDa) have been shown to possess various bioactive properties. However, poor emulsification of EWP limits its application in functional foods. In this study, EWP aggregation induced by proanthocyanidins (PC) contributed to the improvement of emulsion properties. The two-step binding process of PC-EWP-EWP was confirmed by isothermal titration calorimetry, fluorescence spectroscopy, surface hydrophobicity, and Fourier transform infrared spectroscopy. We found that first EWP combines with PC via hydrogen bonding and hydrophobic interactions. Next, more EWPs bind to the EWP in PC-EWP via hydrogen bonding, thereby forming PC-EWP-EWP aggregates. The aggregates (PC to EWP ratio of 1:4) reduced the surface tension (6 %) and improved the contact angle (53 %). The co-adsorption of EWP and aggregates at the O/W interface improved the contact angle, protein adsorption rate, and emulsion stability. This study establishes EWP aggregates induced by PC as an effective emulsifier, thereby expanding the application fields of EWP.

Immunomodulatory effects of egg white peptides on immunosuppressed mice and sequence identification of immunomodulatory peptides

In this study, egg white peptides (EWP) were prepared using preheat treatment combined with a bienzymatic hydrolysis. Results on peptide yield and molecular weight distribution showed that preheat treatment could obviously promote egg white hydrolysis. The yield of EWP obtained from neutral-alkaline protease treatment was 74.62% ± 0.23% and 92.69% of EWP was between 200 Da and 500 Da. Supplementation with 750 mg/kg/d EWP significantly alleviated the decrease of immune organ index in immunosuppressed male BLAB/c mice caused by cyclophosphamide. The pathological changes of spleen showed that EWP could also alleviate the damage of spleen tissue. The number of white blood cells in peripheral blood and the levels of serum cytokines (IL-6, IL-2 and TNF-α) in 750 mg/kg/d EWP group were significantly higher than the model group. The immunomodulatory effects of EWP might be related to the presence of abundant branched-chain amino acids, which were important components of immunomodulatory peptides. Eight possible immunomodulatory peptides were identified from EWP by High Performance Liquid Chromatography-Mass Spectrometry in combination with ProteinLynx Global SERVER and mass spectral database. Therefore, EWP may have potential as a natural immunomodulator for the prevention of immune damage caused by external influences.

Identification, characterization and binding sites prediction of calcium transporter-embryo egg-derived egg white peptides

Identification, characterization and binding sites prediction of calcium transporter-embryo egg-derived egg white peptides

Egg White Peptides Increased the Membrane Liquid-Ordered Phase of Giant Unilamellar Vesicles: Visualization, Localization, and Phase Regulation Mechanism.

Cell membranes are heterogeneous and consist of liquid-ordered (Lo) and liquid-disordered (Ld) phases due to phase separation. Membrane regulation of egg white peptides (LCAY and QVPLW) was confirmed in our previous study. However, the underlying mechanism of phase regulation by the peptides has not been elucidated. This study aimed to explore the effect of LCAY and QVPLW on the membrane phase separation and illustrate their mechanism by giant unilamellar vesicles (GUVs). Based on phase separation visualization, LCAY and QVPLW were found to increase the Lo phase by rearranging lipids and ordering the Ld phase. LCAY and QVPLW can bind to the GUVs and localize in the amphiphilic region of the membrane. By hydrogen bonds and hydrophobic interactions, LCAY and QVPLW may play a cholesterol-like role in regulating phase separation.

Mechanism of Ser-Ala-Gly-Pro-Ala-Phe treatment with a pulsed electric field to improve ethanol-induced gastric mucosa injury in mice

This paper focused on the mechanism of Ser-Ala-Gly-Pro-Ala-Phe (SAGPAF) treatment to improve gastric mucosal injury in mice. A gastric mucosa injury model induced by ethanol was established, and the superoxide dismutase (SOD) activity, malondialdehyde (MDA) content, nitric oxide (NO) content and myeloperoxidase (MPO) level were determined. We performed macroscopic and histopathological evaluation of the gastric organs. Moreover, we analyzed the mechanism of SAGPAF treatment by western blotting. Compared with the model group, the SOD activity and NO content in the medium-dose and high-dose SAGPAF groups of treated with 10 kV cm-1 field intensity were significantly increased. The MDA content and MPO level were decreased significantly. They significantly reduced the gastric mucosal injury induced by ethanol (21.17 ± 3.51% and 13.99 ± 2.00%) and the histopathological scores (3.83 ± 0.40 and 4.33 ± 0.37) (P < 0.05). Western blotting analysis showed that SAGPAF after pulsed electric field (PEF) treatment improved gastric injury by reducing protein phosphorylation. These findings provided strong evidence that PEF-treated SAGPAF enhanced the gastric mucosal barrier function by inhibiting the activation of the mitogen-activated protein kinase (MAPK) and nuclear factor kappa-B (NF-κB) signaling pathways, reducing the ethanol-induced inflammatory response and oxidative stress.

Akkermansia muciniphila in inflammatory bowel disease and colorectal cancer.

Akkermansia muciniphila in inflammatory bowel disease and colorectal cancer.

Elucidating the Calcium-Binding Site, Absorption Activities, and Thermal Stability of Egg White Peptide-Calcium Chelate.

With the current study, we aimed to determine the characteristics and calcium absorption capacity of egg white peptide–calcium complex (EWP-Ca) and determine the effect of sterilization on EWP-Ca to study the possibility of EWP-Ca as a new potential calcium supplement. The results of SEM and EDS showed a high calcium chelating ability between EWP and calcium, and the structure of EWP-Ca was clustered spherical particles due its combination with calcium. The FTIR and Raman spectrum results showed that EWP could chelate with calcium by carboxyl, phosphate, and amino groups, and peptide bonds may also participate in peptide–calcium binding. Moreover, the calcium absorption of EWP-Ca measured by the intestinal everted sac model in rats was 32.38 ± 6.83 μg/mL, significantly higher than the sample with CaCl2, and the mixture of EWP and Ca (p < 0.05) revealed appropriate calcium absorption capacity. The fluorescence spectra and CD spectra showed that sterilization caused a decrease in the content of α-helix and β-sheet and a significant increase in β-turn (p < 0.05). Sterilization changed the EWP-Ca structure and decreased its stability; the calcium-binding capacity of EWP-Ca after sterilization was decreased to 41.19% (p < 0.05). Overall, these findings showed that EWP could bind with calcium, form a peptide–calcium chelate, and serve as novel carriers for calcium supplements.

In vitro caecum fermentation and in vivo (Gallus gallus) of calcium delivery systems fabricated by desalted duck egg white peptides and chitosan oligosaccharide on gut health

AbstractAs calcium supplements, two novel calcium delivery systems were prepared with desalted duck egg white peptides (DPs) and chitosan oligosaccharide (COS) by Amadori‐linkage and transglutaminase (TGase)‐induced reaction, with high calcium‐binding ability of promoting calcium absorption in vivo and in vitro. However, there are relatively few studies on the gut health of calcium delivery systems. In this experiment, in vitro caecum fermentation experiment and Gallus gallus intra amniotic feeding model were used to assess the gut health of calcium delivery systems and phytic acid. Results showed that two calcium delivery systems improved the microbial community structure by inhibiting the proliferation of Escherichia coli, and promoting the proliferation of Bifidobacterium and Lactobacillus. The addition of calcium delivery systems significantly increased short chain fatty acids (SCFAs) and improved the boundary membrane function of brush nutrients by significantly increasing villi structure, surface area, cup cell expansion and production of associated genes (P &lt; 0.05). Moreover, calcium delivery systems present significant reverse of the inhibitory effect of phytic acid on gut health through in vitro and in vivo experiments. This study suggested that DPs‐COS‐Ca systems were superior to the commercially available calcium supplement CaCO3 and had excellent calcium absorption and gut health regulating effects.

Egg White-Derived Peptides QVPLW and LCAY Inhibit the Activity of Angiotensin I-Converting Enzyme in Human Umbilical Vein Endothelial Cells by Suppressing Its Recruitment into Lipid Rafts.

As a membrane protein, the activity of angiotensin I-converting enzyme (ACE) can be modulated via regulation of its localization in the cell membrane with food-derived peptides. This study aimed to explore the effect of egg white peptides on the cell membrane localization and activity of ACE in human umbilical vein endothelial cells. ACE activity was found to be related to lipid rafts by using methyl-β-cyclodextrin (MβCD). QVPLW and LCAY can inhibit ACE activity by preventing ACE recruitment into lipid rafts, with in situ IC50 values of 238.46 ± 11.35 μM and 31.55 ± 2.64 μM in the control groups, as well as 45.43 ± 6.15 μM and 34.63 ± 1.59 μM in the MβCD groups, respectively. QVPLW and LCAY may alter the cell membrane properties, including the fluidity, potential, and permeability, and eventually promote the transposition of ACE.

Preparation, characterization and biological activities of egg white peptides-calcium chelate

The optimal conditions for preparation of egg white peptides-calcium chelate (EWPs-Ca) were determined by response surface methodology (RSM). Under the optimal condition (mass ratio of peptide: calcium of 4:1 at 53 °C and pH 8.2 for 30 min), the calcium content of EWPs-Ca was 44.1 mg/kg. The results of Ultraviolet–Visible absorption spectroscopy (UV) and Fourier transform infrared spectroscopy (FTIR) indicated that the carboxyl oxygen and amino nitrogen atoms of the egg white peptides (EWPs) may chelate with calcium during the chelation. Amino acid analysis suggested that glutamate, aspartic acid, cysteine, threonine, glycine and lysine played important roles during the chelation. The scanning electron microscopy showed that due to EWPs combined with calcium, the structure of EWPs-Ca became loose porous sponge. Moreover, the amount of transferred calcium of EWPs-Ca was 46.18 ± 2.12, 63.86 ± 0.36, 106.91 ± 0.44, 123.61 ± 1.59 μg/mL at 30, 60, 120, 180 min in Caco-2 cell monolayers, respectively. Compared with the blank control, the proliferation rate of Human fetal osteoblast (HFOB) cells reached the maximum value of 119.55 ± 1.36%, 110.20 ± 1.56% and 112.58 ± 1.62% at 24, 48 and 72 h, respectively and EWPs-Ca also improved the activity of alkaline phosphatase (ALP).