Hydrolyzed egg yolk peptide prevented osteoporosis by regulating Wnt/ß-catenin signaling pathway in ovariectomized rats.

Hydrolyzed egg yolk peptide (YPEP) was shown to increase bone mineral density in ovariectomized rats. However, the underlying mechanism of YPEP on osteoporosis has not been explored. Recent studies have shown that Wnt/ß-catenin signaling pathway and gut microbiota may be involved in the regulation of bone metabolism and the progression of osteoporosis. The present study aimed to explore the preventive effect of the YPEP supplementation on osteoporosis in ovariectomized (OVX) rats and to verify whether YPEP can improve osteoporosis by regulating Wnt/ß-catenin signaling pathway and gut microbiota. The experiment included five groups: sham surgery group (SHAM), ovariectomy group (OVX), 17-ß estradiol group (E2: 25 µg /kg/d 17ß-estradiol), OVX with low-dose YPEP group (LYPEP: 10 mg /kg/d YPEP) and OVX with high-dose YPEP group (HYPEP: 40 mg /kg/d YPEP). In this study, all the bone samples used were femurs. Micro-CT analysis revealed improvements in both bone mineral density (BMD) and microstructure by YPEP treatment. The three-point mechanical bending test indicated an enhancement in the biomechanical properties of the YPEP groups. The serum levels of bone alkaline phosphatase (BALP), bone gla protein (BGP), calcium (Ca), and phosphorus (P) were markedly higher in the YPEP groups than in the OVX group. The LYPEP group had markedly lower levels of alkaline phosphatase (ALP), tartrate-resistant acid phosphatase (TRAP) and C-terminal telopeptide of type I collagen (CTX-I) than the OVX group. The YPEP groups had significantly higher protein levels of the Wnt3a, ß-catenin, LRP5, RUNX2 and OPG of the Wnt/ß-catenin signaling pathway compared with the OVX group. Compared to the OVX group, the ratio of OPG/RANKL was markedly higher in the LYPEP group. At the genus level, there was a significantly increase in relative abundance of Lachnospiraceae_NK4A136_group and a decrease in Escherichia_Shigella in YPEP groups, compared with the OVX group. However, in the correlation analysis, there was no correlation between these two bacteria and bone metabolism and microstructure indexes. These findings demonstrate that YPEP has the potential to improve osteoporosis, and the mechanism may be associated with its modulating effect on Wnt/ß-catenin signaling pathway.

Integrating Computational and Experimental Methods to Identify Novel Sweet Peptides from Egg and Soy Proteins.

Sweetness in food delivers a delightful sensory experience, underscoring the crucial role of sweeteners in the food industry. However, the widespread use of sweeteners has sparked health concerns. This underscores the importance of developing and screening natural, health-conscious sweeteners. Our study represents a groundbreaking venture into the discovery of such sweeteners derived from egg and soy proteins. Employing virtual hydrolysis as a novel technique, our research entailed a comprehensive screening process that evaluated biological activity, solubility, and toxicity of the derived compounds. We harnessed cutting-edge machine learning methodologies, specifically the latest graph neural network models, for predicting the sweetness of molecules. Subsequent refinements were made through molecular docking screenings and molecular dynamics simulations. This meticulous research approach culminated in the identification of three promising sweet peptides: DCY(Asp-Cys-Tyr), GGR(Gly-Gly-Arg), and IGR(Ile-Gly-Arg). Their binding affinity with T1R2/T1R3 was lower than -15 kcal/mol. Using an electronic tongue, we verified the taste profiles of these peptides, with IGR emerging as the most favorable in terms of taste with a sweetness value of 19.29 and bitterness value of 1.71. This study not only reveals the potential of these natural peptides as healthier alternatives to traditional sweeteners in food applications but also demonstrates the successful synergy of computational predictions and experimental validations in the realm of flavor science.

Oral Synergism of Egg-White-Derived Peptides (EWDP) and Curcumin for Colitis Mitigation via Polysaccharide/Cyclodextrin Metal-Organic Framework-Based Assemblies.

Recently, oral deliverable strategies of multiple nutraceuticals for ulcerative colitis (UC) mitigation have attracted increasing attention. This study aimed to fabricate facile oral assemblies loaded with egg-white-derived peptides (EWDP) and curcumin based on carboxymethyl chitosan (CMCS) and an γ-cyclodextrin metal-organic framework (MOF). Herein, outer CMCS could coassemble with EWDP (both nutraceuticals and building blocks) into cobweb-like fibrils to promote bridging with inner MOF via coordinative noncovalent interactions (hydrogen bonding, hydrophobic interaction, and electrostatic interaction). Compared with conventional γ-cyclodextrin/MOF-based composites, the above coassembly could also endow the biocompatible assemblies with superior nanoscale colloidal properties, processing applicability (curcumin storage stability, bioaccessibility, and aqueous solubility), and bioactivity. Moreover, the oral synergism of EWDP and curcumin (initially nonsynergistic) for UC mitigation was achieved by alleviating inflammatory damage and gut microbiota imbalance. Overall, the novel assemblies could be a promising amplifier and platform to facilitate oral formulations of various nutraceuticals for food processing and UC relief.

Winners vs. losers: Schistosoma mansoni intestinal and liver eggs exhibit striking differences in gene expression and immunogenicity.

The eggs of the blood fluke Schistosoma mansoni are the main cause of the clinical manifestations of chronic schistosomiasis. After laying, the egg "winners" attach to the endothelium of the mesenteric vein and, after a period of development, induce the growth of a small granuloma, which facilitates their passage to the intestinal lumen. Egg "losers" carried by the bloodstream to non-specific tissues also undergo full development and induce large granuloma formation, but their life ends there. Although these trapped eggs represent a dead end in the parasite life cycle, the vast majority of studies attempting to describe the biology of the S. mansoni eggs have studied these liver-trapped "losers" instead of migrating intestinal "winners". This raises the fundamental question of how these eggs differ. With robust comparative transcriptomic analysis performed on S. mansoni eggs isolated 7 weeks post infection, we show that gene expression is critically dependent on tissue localization, both in the early and late stages of development. While mitochondrial genes and venom allergen-like proteins are significantly upregulated in mature intestinal eggs, well-described egg immunomodulators IPSE/alpha-1 and omega-1, together with micro-exon genes, are predominantly expressed in liver eggs. In addition, several proteases and protease inhibitors previously implicated in egg-host interactions display clear tissue-specific gene expression patterns. These major differences in gene expression could be then reflected in the observed different ability of liver and intestinal soluble egg antigens to elicit host immune responses and in the shorter viability of miracidia hatched from liver eggs. Our comparative analysis provides a new perspective on the biology of parasite's eggs in the context of their development and tissue localization. These findings could contribute to a broader and more accurate understanding of parasite eggs interactions with the host, which have historically been often restricted to liver eggs and sometimes inaccurately generalized.

Traditional cooking methods decreased the allergenicity of egg proteins.

Egg allergy is one of the most common food allergies globally. This study aimed to assess the impact of four traditional cooking methods on the allergenicity of egg proteins using a comprehensive strategy, including simulated gastrointestinal digestion in vitro, serology experiments, a rat basophilic leukemia (RBL)-2H3 cell degranulation model, and a passive cutaneous anaphylaxis (PCA) mice model, and the structure changes were detected by circular dichroism (CD) spectra and ultraviolet (UV) spectra. The results showed that the processed egg proteins were more readily digested compared to raw egg proteins. The serological experiments revealed a significant reduction in immunoglobulin E binding of egg proteins after thermal treatments (p < 0.05), particularly after frying. Subsequently, the RBL-2H3 cell degranulation experiment demonstrated a marked decrease in the level of egg allergens-induced ß-hexosaminidase release after cooking (p < 0.05). Moreover, the results from the PCA mice model indicated that the increase in vascular permeability was effectively relieved in the treated groups, especially in frying group (p < 0.05). Additionally, the α-helix and ß-turn contents of processed egg proteins were significantly decreased (p < 0.05) compared with native egg proteins. The UV spectra findings showed that all cooking treatments caused significant alterations in the tertiary structure, and fluorescence analysis indicated that cooking decreased the surface hydrophobicity of egg proteins. In conclusion, four traditional cooking methods reduced the allergenicity of egg proteins, particularly frying, and this reduction was associated with structural changes that could contribute to the destruction or masking of epitopes of egg allergens. PRACTICAL APPLICATION: Egg allergy has a serious impact on public health, and there is no ideal treatment method at present. This study demonstrated that four traditional cooking methods (boiling, steaming, baking, and frying) reduced the allergenicity of egg proteins, especially frying, and the results will provide a basis for the development of hypoallergenic egg products.

Endogenous reactive oxygen species (ROS)-driven protein oxidation regulates emulsifying and foaming properties of liquid egg white.

Highly oxidative reactive oxygen species (ROS) attack protein structure and regulate its functional properties. The molecular structures and functional characteristics of egg white (EW) protein (EWP) during 28 d of aerobic or anaerobic storage were explored to investigate the "self-driven" oxidation mechanism of liquid EW mediated by endogenous ROS signaling. Results revealed a significant increase in turbidity during the storage process, accompanied by protein crosslinking aggregation. The ROS yield initially increased and then decreased, leading to a substantial increase in carbonyl groups and tyrosine content. The free sulfhydryl groups and molecular flexibility in EWP exhibited synchronicity with ROS production, reflecting the self-repairing ability of cysteine residues in EWP. Fourier-transform infrared spectroscopy indicated stable crosslinking between EWP molecules in the early oxidation stage. However, continuous ROS attacks accelerated EWP degradation. Compared with the control group, the aerobic-stimulated EWP showed a significant decrease in foaming capacity from 30.5 % to 9.6 %, whereas the anaerobic-stimulated EWP maintained normal levels. The emulsification performance exhibited an increasing-then-decreasing trend. In conclusion, ROS acted as the predominant factor causing deterioration of liquid EW, triggering moderate oxidation that enhanced the superior foaming and emulsifying properties of EWP, and excessive oxidation diminished the functional characteristics by affecting the molecular structure.

Targeting TtVgR via siRNA Knockdown Elicits Ovarian Cell Death in the Tri-spine Horseshoe Crab.

The vitellogenin present in the bloodstream undergoes internalization into developing oocytes through the vitellogenin receptor (VgR), a process mediated by receptor-mediated endocytosis. VgR plays a crucial role in facilitating the accumulation of vitellogenin and the maturation of oocytes. In this study, we characterized a Tachypleus tridentatus vitellogenin receptor (TtVgR) gene from the tri-spine horseshoe crab, revealing a length of 1956 bp and encoding 652 amino acid residues with 12 exons. TtVgR has a molecular weight of 64.26 kDa and an isoelectric point of 5.95. Predictions indicate 85 phosphorylation sites and 7 glycosylation sites within TtVgR. Transcriptional analysis demonstrated specific expression of TtVgR in the ovary and yellow connective tissue. TtVgR was identified and distributed in the plasma membrane of oocytes. The siRNA-mediated TtVgR knockdown significantly reduced the transcriptional activity of TtVgR. This depletion induced excessive ROS production, resulting in DNA damage in ovarian primary cells. TUNEL and flow cytometry analyses confirmed ovarian cell apoptosis following TtVgR knockdown, indicating DNA damage in ovarian primary cells. These findings underscore the importance of TtVgR in ovarian cell development, suggesting its potential involvement in vitellogenesis and oocyte maturation. This knowledge may inform innovative breeding strategies and contribute to the sustainable management and conservation of the tri-spine horseshoe crab.

Advances in Understanding the Antioxidant and Antigenic Properties of Egg-Derived Peptides.

Pepsin, trypsin and proteinase K were used in the present study to hydrolyse the proteins from whole eggs, yolks or whites, and the resulting hydrolysates were characterised in terms of antioxidant and IgE-binding properties, using a combination of in vitro and in silico methods. Based on the degree of hydrolysis (DH) results, the egg yolk proteins are better substrates for all the tested enzymes (DH of 6.2-20.1%) compared to those from egg whites (DH of 2.0-4.4%). The SDS-PAGE analysis indicated that pepsin and proteinase K were more efficient compared to trypsin in breaking the intramolecular peptide bonds of the high molecular weight egg proteins. For all the tested substrates, enzyme-assisted hydrolysis resulted in a significant increase in antioxidant activity, suggesting that many bioactive peptides are encrypted in inactive forms in the parent proteins. The hydrolysates obtained with proteinase K exhibited the highest DPPH radical scavenging activity (124-311 µM Trolox/g protein) and the lowest residual IgE-binding capacity. The bioinformatics tools revealed that proteinase K is able to break the integrity of the main linear IgE-binding epitopes from ovalbumin and ovomucoid. It can be concluded that proteinase K is a promising tool for modulating the intrinsic properties of egg proteins.

Proteomic Analysis of Egg Yolk Proteins During Embryonic Development in Wanxi White Goose.

To investigate the alterations of yolk protein during embryonic development in Wanxi white goose, the egg yolk protein composition at days 0, 4, 7, 14, 18, and 25 of incubation (D0, D4, D7, D14, D18, and D25) was analyzed by two-dimensional gel electrophoresis combined with mass spectrometry. A total of 65 spots representing 11 proteins with significant abundance changes were detected. Apolipoprotein B-100, vitellogenin-1, vitellogenin-2-like, riboflavin-binding protein, and serotransferrin mainly participated in nutrient (lipid, riboflavin, and iron ion) transport, and vitellogenin-2-like showed a lower abundance after D14. Ovomucoid-like were involved in endopeptidase inhibitory activity and immunoglobulin binding and exhibited a higher expression after D18, suggesting a potential role in promoting the absorption of immunoglobulin and providing passive immune protection for goose embryos after D18. Furthermore, myosin-9 and actin (ACTB) were involved in the tight junction pathway, potentially contributing to barrier integrity. Serum albumin mainly participated in cytolysis and toxic substance binding. Therefore, the high expression of serum albumin, myosin-9, and ACTB throughout the incubation might protect the developing embryo. Apolipoprotein B-100, vitellogenin-1, vitellogenin-2-like, riboflavin-binding protein, and serotransferrin might play a crucial role in providing nutrition for embryonic development, and VTG-2-like was preferentially degraded/absorbed.

Mechanistic characterization of a Drosophila model of paraneoplastic nephrotic syndrome.

Paraneoplastic syndromes occur in cancer patients and originate from dysfunction of organs at a distance from the tumor or its metastasis. A wide range of organs can be affected in paraneoplastic syndromes; however, the pathological mechanisms by which tumors influence host organs are poorly understood. Recent studies in the fly uncovered that tumor secreted factors target host organs, leading to pathological effects. In this study, using a Drosophila gut tumor model, we characterize a mechanism of tumor-induced kidney dysfunction. Specifically, we find that Pvf1, a PDGF/VEGF signaling ligand, secreted by gut tumors activates the PvR/JNK/Jra signaling pathway in the principal cells of the kidney, leading to mis-expression of renal genes and paraneoplastic renal syndrome-like phenotypes. Our study describes an important mechanism by which gut tumors perturb the function of the kidney, which might be of clinical relevance for the treatment of paraneoplastic syndromes.

Egg White Protein-Proanthocyanin Complexes Stabilized Emulsions: Investigation of Physical Stability, Digestion Kinetics, and Free Fatty Acid Release Dynamics.

Egg white proteins pose notable limitations in emulsion applications due to their inadequate wettability and interfacial instability. Polyphenol-driven alterations in proteins serve as an effective strategy for optimizing their properties. Herein, covalent and non-covalent complexes of egg white proteins-proanthocyanins were synthesized. The analysis of structural alterations, amino acid side chains and wettability was performed. The superior wettability (80.00° ± 2.23°) and rigid structure (2.95 GPa) of covalent complexes established favorable conditions for their utilization in emulsions. Furthermore, stability evaluation, digestion kinetics, free fatty acid (FFA) release kinetics, and correlation analysis were explored to unravel the impact of covalent and non-covalent modification on emulsion stability, dynamic digestion process, and interlinkages. Emulsion stabilized by covalent complex exhibited exceptional stabilization properties, and FFA release kinetics followed both first-order and Korsmeyer-Peppas models. This study offers valuable insights into the application of complexes of proteins-polyphenols in emulsion systems and introduces an innovative approach for analyzing the dynamics of the emulsion digestion process.

Disruption of Zar1 leads to arrested oogenesis by regulating polyadenylation via Cpeb1 in tilapia (Oreochromis niloticus).

Oogenesis is a complex process regulated by precise coordination of multiple factors, including maternal genes. Zygote arrest 1 (zar1) has been identified as an ovary-specific maternal gene that is vital for oocyte-to-embryo transition and oogenesis in mouse and zebrafish. However, its function in other species remains to be elucidated. In the present study, zar1 was identified with conserved C-terminal zinc finger domains in Nile tilapia. zar1 was highly expressed in the ovary and specifically expressed in phase I and II oocytes. Disruption of zar1 led to the failed transition from oogonia to phase I oocytes, with somatic cell apoptosis. Down-regulation and failed polyadenylation of figla, gdf9, bmp15 and wee2 mRNAs were observed in the ovaries of zar1-/- fish. Cpeb1, a gene essential for polyadenylation that interacts with Zar1, was down-regulated in zar1-/- fish. Moreover, decreased levels of serum estrogen and increased levels of androgen were observed in zar1-/- fish. Taken together, zar1 seems to be essential for tilapia oogenesis by regulating polyadenylation and estrogen synthesis. Our study shows that Zar1 has different molecular functions during gonadal development by the similar signaling pathway in different species.

Effect of pH treatment on egg white protein digestion and the peptidomics of their in vitro digests.

The pH treatment significantly enhanced the functional properties of egg white protein (EWP), but little is known about the relationship between pH treatment and in vitro digestion of EWP. In this paper, we explored the effect of pH treatment (pH 2, pH 2-7, pH 12 and pH 12-7) on the digestibility of egg white protein and peptide profiling using the digestion kinetics and peptidomics methods, separately. The results implied that all pH treatment reduced the protein digestibility in gastric phase, while alkaline pH (pH 12 and pH 12-7) showed greater digestion level and more gastric peptides, and more importantly, produced a greater amount of potentially bioactive peptides than acid treated samples. Besides, the least number of potentially bioactive peptides was obtained at pH 2, but this could be improved by adjusting pH 2 back to 7. Notably, the unique bioactive peptides induced by pH were mainly relevant to DPP IV inhibitor. These differences of digestibility and peptide profiling might be attributed to the change of protein structure and the formation of molten sphere, altering cleavage sites of digestive enzymes. This work would give an enlightening insight into the digestive and nutritional characteristics of the pH-induced EWP to expand their application in the field of food and healthcare.

Characterization of essential eggshell proteins from Aedes aegypti mosquitoes.

BACKGROUND: Up to 40% of the world population live in areas where mosquitoes capable of transmitting the dengue virus, including Aedes aegypti, coexist with humans. Understanding how mosquito egg development and oviposition are regulated at the molecular level may provide new insights into novel mosquito control strategies. Previously, we identified a protein named eggshell organizing factor 1 (EOF1) that when knocked down with RNA interference (RNAi) resulted in non-melanized and fragile eggs that did not contain viable embryos. RESULTS: In this current study, we performed a comprehensive RNAi screen of putative A. aegypti eggshell proteins to identify additional proteins that interact with intracellular EOF1. We identified several proteins essential for eggshell formation in A. aegypti and characterized their phenotypes through a combination of molecular and biochemical approaches. We found that Nasrat, Closca, and Polehole structural proteins, together with the Nudel serine protease, are indispensable for eggshell melanization and egg viability. While all four proteins are predominantly expressed in ovaries of adult females, Nudel messenger RNA (mRNA) expression is highly upregulated in response to blood feeding. Furthermore, we identified four additional secreted eggshell enzymes that regulated mosquito eggshell formation and melanization. These enzymes included three dopachrome-converting enzymes (DCEs) and one cysteine protease. All eight of these eggshell proteins were essential for proper eggshell formation. Interestingly, their eggshell surface topologies in response to RNAi did not phenocopy the effect of RNAi-EOF1, suggesting that additional mechanisms may influence how EOF1 regulates eggshell formation and melanization. CONCLUSIONS: While our studies did not identify a definitive regulator of EOF1, we did identify eight additional proteins involved in mosquito eggshell formation that may be leveraged for future control strategies.

Analysis of differentially expressed genes discovers Latroeggtoxin VI-induced changes and SYNJ1 as a main target in PC12 cells.

BACKGROUND: Previous preliminary work found that Latroeggtoxin-VI (LETX-VI), a proteinaceous neurotoxin from the eggs of spider Latrodectus tredecimguttatus, could promote the synthesis and release of dopamine in PC12 cells. However, the underlying mechanisms have not been fully clear. Here, the effects of LETX-VI on the gene expression profile and dopamine in PC12 cells were analyzed with the differential transcriptome-based strategies. RESULTS: After treatment of PC12 cells with LETX-VI for 24 h, a total of 356 differentially expressed transcripts were identified. Of them 165 were up-regulated and 191 down-regulated. Relevant GO analysis indicated that LETX-VI modulated the expression of certain genes and thereby affected multiple biological processes in PC12 cells, including protein metabolism, nucleic acid metabolism, substance transport, signaling, neurotransmitter metabolism and release. When western blot analysis was employed to confirm the abundance levels of synaptojanin 1 and synuclein alpha interacting protein, the representatives of highly up- and down-regulated transcript-encoded proteins that are closely related with dopamine respectively, it was found that the level of synaptojanin 1 in the PC12 cells treated with LETX-VI was increased, whereas that of synuclein alpha interacting protein was not obviously altered, suggesting that synaptojanin 1 may be much more involved in the effects of LETX-VI on dopamine. After synaptojanin 1 level was knocked down using siRNA, the levels of both total and released dopamine were significantly decreased, indicating that synaptojanin 1 is a protein positively modulating the synthesis and secretion of dopamine. When the PC12 cells with knocked down synaptojanin 1 were treated by LETX-VI, the adverse effects of synaptojanin 1 knockdown on dopamine were attenuated, confirming that LETX-VI promotes the synthesis and secretion of dopamine at least partially by enhancing the expression of the gene SYNJ1 encoding synaptojanin 1. CONCLUSIONS: This work demonstrates that LETX-VI exerts multiple regulatory effects on the cellular processes in PC12 cells by altering the gene expression profile. LETX-VI modulates the expression of the genes closely related to the synthesis, transport and release of neurotransmitters especially dopamine in PC12 cells, with the gene SYNJ1 encoding synaptojanin 1 as a main target.

Potential Benefits of Egg White Proteins and Their Derived Peptides in the Regulation of the Intestinal Barrier and Gut Microbiota: A Comprehensive Review.

Impaired intestinal barrier function can impede the digestion and absorption of nutrients and cause a range of metabolic disorders, which are the main causes of intestinal disease. Evidence suggests that proper dietary protein intake can prevent and alleviate intestinal diseases. Egg white protein (EWP) has received considerable attention, because of its high protein digestibility and rich amino acid composition. Furthermore, bioactive peptides may have an increased repair effect due to their high degradation efficiency in the gut. In this study, we aimed to review the effects of EWP and its bioactive peptides on intestinal structural repair. The potential modulation mechanisms by which EWP and their peptides regulate the gut microbiota and intestinal barrier can be summarized as follows: (1) restoring the structure of the intestinal barrier to its intact form, (2) enhancing the intestinal immune system and alleviating the inflammatory response and oxidative damage, and (3) increasing the relative abundance of beneficial bacteria and metabolites. Further in-depth analysis of the coregulation of multiple signaling pathways by EWP is required, and the combined effects of these multiple mechanisms requires further evaluation in experimental models. Human trials can be considered to understand new directions for development.

[Effect of the chicken zp1 gene on osteoblast mineralization].

The aim of this study was to clone the chicken zp1 gene encoding zona pellucida 1 (Zp1) and investigate its tissues expression profile and its effect on osteoblast mineralization. The expression level of zp1 was quantified in various tissues of laying hens and in the tibia of the pre- and post-sexual maturity by RT-qPCR. Zp1 overexpressed vector was transfected into chicken calvarial osteoblasts which were induced differentiation for 8 days, and the extracellular mineral and the expression of mineralization-related genes were detected. The full-length chicken zp1 gene is 3 045 bp, encoding 958 amino acids residuals, and has two N-glycosylation sites. The highest expression level of the zp1 gene was found in the liver, followed by the tibia and yolk membrane, while no expression was detected in the heart and eggshell gland. Compared with the pre-sexual maturity hens, the concentration of estrogen (E2) in plasma, the content of glycosaminoglycan (GAG) and the expression level of the zp1 gene in the tibia with post-sexual maturity were higher. The extracellular matrix and the level of osteoblast mineralization-related genes showed a significantly upregulated expression in chicken calvarial osteoblasts with Zp1 overexpressed and addition of estrogen. The expression of the zp1 gene is tissue-specific and positively regulated osteoblast mineralization under the action of estrogen, laying the foundation for elucidating the functional properties of Zp1 in chicken bones during the egg production period.

A new insight into the influence of pH on the adsorption at oil-water interface and emulsion stability of egg yolk protein.

This study investigated the impact of varied pH treatments on the structural, emulsification, and interfacial adsorption properties of egg yolk. The solubility of egg yolk proteins decreased and then increased in response to pH changes, with a minimum value (41.95 %) observed at pH 5.0. The alkaline condition (pH 9.0) significantly impacted the secondary/tertiary structure of egg yolk, with the yolk solution displaying the lowest surface tension value (15.98 mN/m). Emulsion stability was found to be optimal when egg yolk was used as the stabilizer at pH 9.0, which corresponded to the more flexible diastolic structure, smaller emulsion droplets, increased viscoelasticity, and enhanced resistance to creaming. At pH 9.0, proteins exhibited a maximum solubility (90.79 %) due to their unfolded conformation, yet the protein adsorption content at the oil-water interface showed relatively low (54.21 %). At this time, electrostatic repulsion between the droplets and the spatial site barrier made by proteins that were unable to efficiently adsorb at the oil-water interface kept the emulsion stable. Moreover, it was found that different pH treatments could effectively regulate the relative adsorption contents of various protein subunits at the oil-water interface, and all proteins except livetin displayed good interfacial adsorption capacity at the oil-water interface.

The Impact of Processing and Extraction Methods on the Allergenicity of Targeted Protein Quantification as Well as Bioactive Peptides Derived from Egg.

This review article discusses advanced extraction methods to enhance the functionality of egg-derived peptides while reducing their allergenicity. While eggs are considered a nutrient-dense food, some proteins can cause allergic reactions in susceptible individuals. Therefore, various methods have been developed to reduce the allergenicity of egg-derived proteins, such as enzymatic hydrolysis, heat treatment, and glycosylation. In addition to reducing allergenicity, advanced extraction methods can enhance the functionality of egg-derived peptides. Techniques such as membrane separation, chromatography, and electrodialysis can isolate and purify specific egg-derived peptides with desired functional properties, improving their bioactivity. Further, enzymatic hydrolysis can also break down polypeptide sequences and produce bioactive peptides with various health benefits. While liquid chromatography is the most commonly used method to obtain individual proteins for developing novel food products, several challenges are associated with optimizing extraction conditions to maximize functionality and allergenicity reduction. The article also highlights the challenges and future perspectives, including optimizing extraction conditions to maximize functionality and allergenicity reduction. The review concludes by highlighting the potential for future research in this area to improve the safety and efficacy of egg-derived peptides more broadly.

Establishment and application of multiple immunoassays for environmental estrogens based on recombinant Japanese flounder (Paralichthys olivaceus) choriogenin protein.

Environmental estrogens have generated great concern because of their potential threat to aquatic organisms; however, the commonly used vitellogenin (Vtg) biomarker detection methods are not capable of detecting estrogenic activity below 10 ng/L 17ß-estradiol. In this study, we developed multiple immunoassays based on Japanese flounder (Paralichthys olivaceus) choriogenin (Chg), a highly sensitive biomarker of environmental estrogens. Chg genes (ChgL and ChgH) of Japanese flounder were cloned for the first time, and a recombinant ChgL protein with a molecular weight of approximately 52 kDa was prepared using a prokaryotic expression system and purified using Ni-affinity column chromatography. Subsequently, specific monoclonal antibodies against ChgL were prepared and used to develop sandwich enzyme-linked immunosorbent assays (ELISAs), which had a detection range of 3.9-250 ng/mL and detection limit of 1.9 ng/mL. An immunofluorescence method was also established and used to visually detect ChgL induction in the tissues. In addition, a lateral flow immunoassay for ChgL that could detect estrogen activity within 10 min was developed. Finally, the reliability of the immunoassays was examined by measuring ChgL induction in the plasma and tissues of Japanese flounder exposed to 0, 2, 10, and 50 ng/L 17α-ethinylestradiol (EE2). The results showed that 2 ng/L EE2 notably increased ChgL levels in the plasma, demonstrating that ChgL is more sensitive than Vtg to environmental estrogens; 50 ng/L EE2 induced obvious Chg induction in the sinusoidal vessels of the liver. Conclusions taken together, this study provides reliable methods for sensitive and rapid detection of estrogenic activity in aquatic environments.