Chicken Egg Yolk Research Articles

Identification and quantification of unreported sialylated N-glycan isomers with α2-3 and α2-6 linkages in the egg yolk protein phosvitin

Phosvitin (PV), a highly phosphorylated protein found in chicken egg yolk, possesses multiple bioactivities (including anti-aging and anticancer) and functional properties (including emulsifier and metal-binding capacities). The carbohydrate moiety attached to PV has been reported, but its N-glycan structure is unknown. In this study, we performed structural and quantitative analyses of N-glycans from PV using liquid chromatography-tandem mass spectrometry (MS/MS). N-glycan structures were identified using observed precursor ion m/z and MS/MS fragment ions. Each quantity was obtained relative to the total N-glycans (100%). Thirty-seven N-glycans were identified, including 22 sialylations with a negative charge (a sum of the relative quantity of each, 96.4%) comprising 13 mono- (31.6%), 7 di- (57.5%), 2 tri- (7.3%) sialylations. The sialylated N-glycan isomers with α2-3 (flexible conformation) and α2-6 (rigid conformation) linkages were distinguished using α2-3- and α2-3,6 sialidase treatments and intensity ratios of the N-acetylglucosamine and sialic acid ions (Ln/Nn) with different fragmentation stabilities. The α2-6/α2-6 (53.8%), α2-6 (31.6%), α2-3/α2-6/α2-6 (6.5%), and α2-3/α2-6 (3.7%) linkages in mono-, di, or tri-antennary structures were identified. These negatively charged structures may affect the emulsification and metal-binding capacity of PV. This is the first study to identify and quantify N-glycans in PV, including predominantly 22 sialylated N-glycan isomers with more rigid α2-6 linkages than α2-3 linkages.

Protective Effect of IgY Embedded in W/O/W Emulsion on LPS Enteritis-Induced Colonic Injury in Mice.

Chicken yolk immunoglobulin (IgY), an immunologically active component, is used as an alternative to antibiotics for the treatment of enteritis. In this study, IgY was embedded in a W/O/W emulsion to overcome the digestive barrier and to investigate the protective effect of IgY against LPS-induced enteritis in mice. Four different hydrophilic emulsifiers (T80, PC, SC, and WPI) were selected to prepare separate W/O/W emulsions for encapsulating IgY. The results showed that the IgY-embedded double emulsion in the WPI group was the most effective. IgY embedded in the W/O/W emulsion could reduce the damage of LPS to the mouse intestine and prevent LPS-induced intestinal mucosal damage in mice. It increased the number of cup cells, promoted the expression of Muc2, and increased the mRNA expression levels of KLF3, TFF3, Itln1, and Ang4 (p < 0.05). It also enhanced the antioxidant capacity of the colon tissue, reduced the level of inflammatory factors in the colon tissue, and protected the integrity of the colon tissue. Stable embedding of IgY could be achieved using the W/O/W emulsion. In addition, the IgY-embedded W/O/W emulsion can be used as a dietary supplement to protect against LPS-induced enteritis in mice.

Evaluation of chicken embryo extract and egg yolk extract as alternatives to basic cell culture medium supplement

BackgroundFetal calf serum (FCS), an existing cell culture supplement, is effective but has several drawbacks, including being expensive, requiring a lengthy process of production, and requiring a hard currency. With this in mind, we planned to evaluate chick embryo extract and egg yolk extracts in cell culture as alternatives to fetal calf serum (FCS).MethodsSpecific pathogen-free eggs were purchased from the National Veterinary Institute, Bishoftu, Ethiopia, and incubated in a humidified incubator at 37 °C for 11 days. Egg yolk extract (EYE) and chick embryo extract (CEE) were collected after the egg was opened with caution not to destroy the yolk sack or the chick embryo itself. Chick fibroblasts and Vero cells were cultured in minimum essential medium (MEM) supplemented with egg yolk extract or chick embryo extract at ratios of 0:10, 1:9, 2.5:7.5, and 5:5% fetal calf serum.ResultsFibroblast cell attachment was better in media supplemented with 5% CEE and 5% FCS. The confluency was also greater than 50% at this concentration. Vero cells cultured with 5% CEE and 5% FCS also exhibited very good cell attachment and a confluency of up to 70%. Viability and confluency were also observed at 5%:5% ratios of 50 and 70%, respectively.ConclusionThis investigation evaluated these two extracts as cell culture supplements and revealed promising results as alternatives to fetal calf serum. The limitation of this study is that it only used two cell types and additional cell lines, and different ratios should be tested. With the above findings, further research using different cell lines, ratios and conditions is warranted.

Comprehensive risk assessment of lead concentrations in chicken, quail, and duck egg albumen and yolk using Monte Carlo simulations

This study conducted a comparative analysis of the concentration of the lead (Pb) in the albumen and yolk of eggs from domesticated chicken, quail, and duck, with a concurrent assessment of the potential carcinogenic and non-carcinogenic risks associated with the consumption of eggs sourced from Türkiye. A total of 78 poultry egg samples were gathered from breeding farms and farmers' markets situated in Şanlıurfa province. Lead concentrations were assessed through inductively coupled plasma optical emission spectrometry (ICP-OES). Human health risk assessment adheres to the guidelines set forth by the United States Environmental Protection Agency (US EPA), which primarily emphasizes estimated daily intake (EDI), international lifetime cancer risk (ILCR), target hazard quotient (THQ), and Monte Carlo simulation (MCS) as a probabilistic approach. One-way analysis of variance (ANOVA) was employed to compare Pb concentrations within egg yolks and albumens, as well as among various types of eggs. The levels of Pb found in the albumen of chicken, quail, and duck eggs were measured to be 0.31 ± 0.11, 0.43 ± 0.11, and 0.47 ± 0.16 μg kg−1, respectively. The concentrations of Pb in the yolks of chicken, quail, and duck eggs were found to be 0.54 ± 0.19, 0.28 ± 0.11, and 0.69 ± 0.21 μg kg−1, respectively. These concentrations were below the maximum permitted levels set by the FAO/WHO. The results indicated that Pb content in all tested eggs was safe for consumption, with exposure levels significantly below Joint FAO/WHO Expert Committee on Food Additives (JECFA) risk thresholds. The THQ values were less than one, indicating no non-carcinogenic risk. In addition, this study provides accurate and reliable data for policy makers to improve food safety measures and reduce potential public health risks.

Study of Making Gluten-Free Fettuccine from Taro Flour (Colocasia esculenta L. Schoot)

We often encounter fettuccine pasta in cafes and restaurants, usually made from wheat flouras the main ingredient. Wheat flour is a food ingredient that contains gluten, which is a proteincompound from cereals that cause allergies and irritate the small intestine and can also causeceliac (autoimmune) disease in certain people. Several studies have substituted wheat flourfor making fettuccine with non-gluten taro flour. The formula obtained is still a mixture of taroflour and wheat flour. This research used 100% pure taro flour with additional ingredients oftwo types of egg yolk, namely chicken egg yolk and duck egg yolk. This research aimed todetermine the organoleptic results of fettuccine from 100% taro flour based on theformulation using the type of egg yolk and boiling time. This study used a completelyrandomized trial (CRD) design with four treatments and two repetitions. The types oftreatment in this study were the use of duck eggs with a boiling time of 35 seconds, the use ofboiled duck eggs for 1 minute, the use of boiled chicken eggs for 35 seconds, and the use ofboiled chicken eggs for 1 minute. The research results showed that fettuccine was successfullymade using 100% taro flour without being mixed with wheat, using additional egg yolk as abinder. A perfect assessment was obtained from the expert panelists for the duck egg yolkformula boiling for 1 minute. The type of egg yolk and boiling time affect the sample in termsof taste, color, and texture, but not aroma.

Coconut water combined with purebred chicken egg yolk as an alternative semen extender for Madura Pote bucks semen preservation

One of the many efforts to increase the quality of livestock genetics is through artificial insemination (AI). Other than increasing it, AI can be conducted to preserve semen. A successful AI is determined by seminal quality, therefore, a method to preserve semen for a longer storage time is needed. The method used is adding an extender that fulfills prerequisites for a semen extender such as coconut water combined with egg yolk citrate extender. Coconut water is rich in carbohydrates, protein, vitamins, and antioxidants while egg yolk contains lecithin. This study aims to find out the Pote buck spermatozoa quality stored in coconut water and egg yolk extender. This study uses three groups of treatments (T0: 0.1 ml semen + 0.9 ml egg yolk citrate, T1: 0.1 ml semen + 0.9 ml coconut water, and T2: 0.1 ml semen + egg yolk citrate (20%) + coconut water). All three of these are stored at 5oC and evaluated every day until day 5 of their motility, viability, intact plasma membrane, abnormality, and MDA level. Data analysis used is ANOVA and a further test called BNT is conducted if a significant difference is determined. No significant difference was found between T0 and T1 (p&gt;0.05). The highest progressive motility, viability, and intact plasma membrane (%) among the three groups of treatments happened to be from T2. Meanwhile, a low percentage of spermatozoa abnormality and MDA level were also found in T2 with its extender being coconut water combined with egg yolk citrate. To conclude, the best extender for storing Pote buck semen is stored at 5oC is coconut water combined with egg yolk citrate extender.

Research Note: Comprehensive proteomic, phosphoproteomic, and N-glycoproteomic analysis of chicken egg yolk plasma

Chicken egg yolk plasma (EYP), the supernatant fraction of egg yolk obtained by water dilution and centrifugation, is a rich source of various bioactive substances and a significant bearer of yolk-emulsifying properties. This study utilized proteomics to conduct a comprehensive and in-depth analysis of both common and modified EYP proteins (phosphorylated proteins and N-glycosylated proteins). Total of 208 proteins were identified in EYP, including 42 phosphorylated proteins with 137 phosphorylation sites and 150 N-glycoproteins with 332 N-glycosylation sites. Among the phosphorylation sites, tyrosine accounted for 80.6%, while the N-glycosylation sites predominantly featured "N-X-T" motifs, accounting for 58.7%. Functional enrichment analysis revealed that most proteins were involved in regulating enzyme activity and inhibition with a particular focus on modulating peptidase activity. Notably, vitellogenins-2 (30 phosphorylation sites, 9 N-glycosylation sites) and apolipoprotein B (10 phosphorylation sites, 56 N-glycosylation sites) were the 2 proteins with the most modification sites. Additionally, EYP was found to contain the highly N-glycosylated complement proteins C3 and C4. These findings provide new insights into the protein composition of EYP and its roles in chicken embryo development and immune defense, offering a theoretical foundation for the application of EYP in various fields.

Quantitative metabolomic analysis of yolk granules from different poultry eggs

A systematic comparison of the nutrient composition of yolk granules from different poultry egg sources may provide a reference for the development of nutritionally balanced foods with high protein, low fat, and low cholesterol content. The metabolomic profiles of chicken, duck, and quail egg yolk granules were analysed quantitatively using UPLC-MS/MS. A total of 820 metabolites were identified, with amino acids and their metabolites (232), glycerophospholipids (121), and organic acids and their derivatives (96), representing the three most abundant metabolite classes in egg yolk granules. The quantitative results demonstrated that amino acids and their metabolites, as well as glycerophospholipids (GP), exhibited significant differences among the three egg yolk granules. A total of 13 coenzymes and vitamins were identified in the three egg yolk granules, with the majority belonging to the B vitamins and their derivatives. A total of 11 bile acids were identified in the three egg yolk granules, including four primary and seven secondary bile acids. A total of 20 significantly different metabolites were preliminarily identified as potential markers for the differentiation of poultry egg yolk granules. This information provides crucial insights into the nutritional composition of egg yolk granules from diverse sources.

Evaluation of SARS-CoV-2-Specific IgY Antibodies: Production, Reactivity, and Neutralizing Capability against Virus Variants.

The emergence of SARS-CoV-2 in late 2019 initiated a global pandemic, which led to a need for effective therapeutics and diagnostic tools, including virus-specific antibodies. Here, we investigate different antigen preparations to produce SARS-CoV-2-specific and virus-neutralizing antibodies in chickens (n = 3/antigen) and rabbits (n = 2/antigen), exploring, in particular, egg yolk for large-scale production of immunoglobulin Y (IgY). Reactivity profiles of IgY preparations from chicken sera and yolk and rabbit sera were tested in parallel. We compared three types of antigens based on ancestral SARS-CoV-2: an inactivated whole-virus preparation, an S1 spike-protein subunit (S1 antigen) and a receptor-binding domain (RBD antigen, amino acids 319-519) coated on lumazine synthase (LS) particles using SpyCather/SpyTag technology. The RBD antigen proved to be the most efficient immunogen, and the resulting chicken IgY antibodies derived from serum or yolk, displayed strong reactivity with ELISA and indirect immunofluorescence and broad neutralizing activity against SARS-CoV-2 variants, including Omicron BA.1 and BA.5. Preliminary in vivo studies using RBD-lumazine synthase yolk preparations in a hamster model showed that local application was well tolerated and not harmful. However, despite the in vitro neutralizing capacity, this antibody preparation did not show protective effect. Further studies on galenic properties seem to be necessary. The RBD-lumazine antigen proved to be suitable for producing SARS-CoV-2 specific antibodies that can be applied to such therapeutic approaches and as reference reagents for SARS-CoV-2 diagnostics, including virus neutralization assays.

The Meaning of Symbols in The Peucicap Aneuk Procession in Aceh: A Semiotic Study

The Peucicap Aneuk tradition is part of past culture with historical value. In its implementation there are religious symbols that have their own meaning. The approach used in this research is semiotic theory to read and understand the meaning of the symbols used by the people of Aceh during the implementation of the Peucicap Aneuk procession. with descriptive qualitative research design. primary data of this research comes from field observations of the Peucicap Aneuk procession and secondary data comes from journals, books, and ancient Acehnese manuscripts. This research showed that, in general, the Acehnese people perform the Peucicap Aneuk procession in the morning on the 7th (seventh) day after a mother gives birth to her child. When the peucicap ritual is carried out, there are 17 (seventeen) symbols, namely rice and paddy, sticky rice, Tumpo, On Peusijuek, free-range chicken egg yolk, rice kneaded into porridge, honey, Zam-Zam water, fruits, chicken thighs, chicken liver, turmeric, salt, sugar, coconut, mirror, Quran. In the Peucicap Aneuk procession, this article confirms the expectations of every parent for their children through the representation of cultural symbols. This article shows that there are several relations between the role of these symbols and the spirit of the community to preserve this culture in line with Islamic values.

Free iron accumulation and oxidative stress burden induce ferroptotic atrophy of chicken yolk sac during the late embryogenesis

AbstractThe aim of this study was to investigate the mechanism of iron homeostasis and the ferroptosis pathway for yolk sac atrophy during late embryogenesis. To study the mechanism of yolk sac atrophy, 100 eggs were used. Further, 500 eggs were randomly divided into five treatments and in ovo feeding with different iron sources, such as FeSO4, ferrous glycinate (Fe‐Gly), or deferoxamine (DFO), to study the effects of free iron content on hatching quality and embryonic development. The results showed that total iron content of yolk decreased, but yolk sac increased from embryonic(E)13 to E19 (p &lt; 0.05). Comparison of gene expression of iron transport systems showed that free iron accumulation and dysfunction occurred in the yolk sac. Yolk sac metabolites at E19 compared to E13 were more enriched in histidine and sulfur pathways, suppressing glutathione synthesis and resulting in oxidative stress damage in the yolk sac. Combined analysis of differential metabolites and gene expression in ferroptosis pathway at E13 and E19 revealed the activation of the yolk sac during late embryogenesis was probably through up‐regulation of ACSL4 expression and down‐regulation of GPX4 expression. Furthermore, in ovo feeding FeSO4 shortened the incubation time compared to CON, while Fe‐Gly or DFO delayed the hatching peak and increased hatching weight with less residual yolk. Collectively, it can be concluded that yolk sac atrophy during late embryogenesis may be mediated by iron disorders and provides a novel insight to modulate yolk sac nutrition, and hatching efficiency in chickens.

Generation of chicken-based IgY polyclonal antibodies against Dendroaspis polylepis and preclinical evaluation of envenomation-neutralizing efficacy vis-à-vis selected commercial antivenoms

The Black mamba, D. polylepis, is one of the many venomous snakes found in Kenya, and known to account for some snakebite incidents. The Kenyan Ministry of Health data reveals annual 15,000 snakebites occurrences. Also, 1 in 15 people in Kenya gets bitten by a snake, and tragically, 1 in 147 of these individuals die of snakebite yearly. Traditionally, antivenoms for treatment are produced from horse or sheep but have complicated and expensive production issues. Alternative production approaches, such as using IgY antibodies derived from chicken egg yolks, may overcome disadvantages with traditional antivenom manufacturing techniques. In this current study, D. polylepis specific IgY polyclonal antibodies were purified from the egg yolks of chickens immunized with D. polylepis venom. These antibodies were subsequently assessed for their in-vivo neutralizing capacity vis-à-vis commercial antivenoms, PANAF-Premium and VINS. The IgY antibodies were purified by ammonium sulfate precipitation and affinity-chromatography, with quality and specificity determined by SDS-PAGE and ELISA. The LD50 of D. polylepis was found to be 0.54 mg/kg in chicks, and 0.34 mg/kg in mice, respectively. Pool of extracted IgY yielded 2.8 mg/mL concentration. Purified IgY under non-reducing and reducing conditions on SDS-PAGE exhibited a single-protein band of about 183 kDa and two bands (67 kDa and 25 kDa), respectively. The minimum-edematogenic dose was 0.05 μg. Anti-D. polylepis IgY antibodies and two antivenoms demonstrated the capacity to neutralize the toxic activities of D. polylepis venom. This study confirms a successful IgY generation against Black mamba venom for the first time, and observed toxic effects of the venom as well as neutralizing capacity of antivenoms.

Development of chicken egg yolk antibodies (IgY) against venom of cobra (Naja naja) and krait (Bungarus caeruleus) and a study on its neutralization potential

The Big Four snakes are the leading causes of snakebite mortality in India. Among them, The Indian spectacled cobra (Naja naja) and common krait (Bungarus caeruleus) contribute about one-third of the deaths. The conventional anti-snake venoms (ASV) produced from equine serum are found to be expensive, with a high frequency of clinical side effects, low specificity, and production drawbacks. The current study, therefore, attempted to develop chicken egg yolk immunoglobulins (IgY) as antivenoms against the venoms of cobra and krait venoms. The major pathophysiological properties of the venoms and the efficacy of monovalent ASV IgY were evaluated. The titer of anti-cobra and anti-krait IgY was found to be 1:64000 on the 145th day post-immunization. The results showed that venoms (lethal doses (LD50): cobra:0.375 mg/kg, krait:0.0375 mg/kg of mice) had hemolytic, pro-coagulant, inflammatory, hemorrhagic, and edematic activities that were effectively neutralized by ASV-IgY. 1 mL of monovalent ASV IgY was able to neutralize 0.22 mg of cobra venom and 0.028 mg of krait venom whereas 1 mL of commercial polyvalent antivenom was able to neutralize 0.28 mg of cobra venom and 0.035 mg of krait venom. The study results suggest that using chicken IgY as an monovalent antivenom could effectively treat snakebites.

Pre-clinical Efficacy and Immunogenicity of IgY Antibodies Directed Against Crotalus durissus cumanensis Venom

Background:: Crotalus durissus cumanensis (C.d.c.) is the most widely distributed snake in Venezuela, causing the majority of snakebite envenoming Objective:: The purpose of this study was to produce IgY antibodies against a C.d.c. venom pool from different Venezuelan regions and evaluate their neutralization capacity on various venom toxic activ-ities. Methods:: Anti-C.d.c. venom antibodies are purified from chicken egg yolks by precipitation with polyethylene glycol and further analyzed by Multiple Antigen Blot Assay, indirect ELISA, Western blot, and Inhibition assays. In addition, we evaluate the phospholipase, edematogenic, and hemor-rhagic activities. In addition, a new envenoming simulation study using anti-C.d.c. venom IgY in mice is presented. Results:: In this study, we show that anti-C.d.c. venom IgY is capable of neutralizing 4LD50 doses of the Cdc venom (i.e., 1.76 mg of IgY neutralized 14 μg of C.d.c. venom) and effectively neutralizing the phospholipase, edematogenic and hemorrhagic activities. Additionally, the anti C.d.c. venom IgY specifically recognizes polypeptide bands with apparent molecular masses of ~ 54.55, 30.39, 24.1, 14.02, and 9.44 kDa by western blot. The IgY specificity is demonstrated by a dose-dependent inhi-bition, in which antibodies pre-adsorbed with the C.d.c. venom does not recognize the proteins con-tained in the venom. Furthermore, in the simulation study of envenoming, the mice inoculated with IgY showed no response. Conclusion:: Our results support the use of anti-venom IgY as an alternative to traditional equine therapy in animals and, eventually, in human patients bitten by C.d.c snakes. conclusion: Our results support the use of anti-venom IgY as an alternative to traditional equine therapy in animals and, eventually, in human patients bitten by C.d.c snakes.

Rapid development and mass production of SARS-CoV-2 neutralizing chicken egg yolk antibodies with protective efficacy in hamsters

Despite the record speed of developing vaccines and therapeutics against the SARS-CoV-2 virus, it is not a given that such success can be secured in future pandemics. In addition, COVID-19 vaccination and application of therapeutics remain low in developing countries. Rapid and low cost mass production of antiviral IgY antibodies could be an attractive alternative or complementary option for vaccine and therapeutic development. In this article, we rapidly produced SARS-CoV-2 antigens, immunized hens and purified IgY antibodies in 2 months after the SARS-CoV-2 gene sequence became public. We further demonstrated that the IgY antibodies competitively block RBD binding to ACE2, neutralize authentic SARS-CoV-2 virus and effectively protect hamsters from SARS-CoV-2 challenge by preventing weight loss and lung pathology, representing the first comprehensive study with IgY antibodies. The process of mass production can be easily implemented in most developing countries and hence could become a new vital option in our toolbox for combating viral pandemics. This study could stimulate further studies, optimization and potential applications of IgY antibodies as therapeutics and prophylactics for human and animals.

Yellowness of egg yolks influences consumer preference for eggs in Ghana

The present work evaluated β-carotene content, colour (L*, a*, b*), and consumer preference for egg yolks from chicken, guinea fowl, and quail, sampled from intensive or semi-intensive rearing systems in Ghana. The β-carotene content of guinea fowl yolk was almost seven times greater (p &lt; 0.001) than that of chicken and quail yolks. The yellowness of guinea fowl yolk (82.18; p &lt; 0.01) was approximately 1.5 and 1.3 times greater than that of chicken and quail yolks, respectively. A consumer preference test showed a significantly greater score (5; p &lt; 0.001) for guinea fowl than for the other egg types. The yellowness of egg yolks had strong positive relationship with β-carotene content (r = 0.943; p = 0.216) and consumer preference (r = 0.995; p = 0.064). Therefore, enhancing the yellowness of egg yolks on the Ghanaian market, especially those from chicken, could lead to increased egg consumption in Ghana.

Effects of feeding chicken egg yolk antibodies on intestinal cell apoptosis, oxidative stress and microbial flora of tilapia (Oreochromis niloticus) infected with Streptococcus agalactiae

Streptococcosis, the most common bacterial disease of fish in recent years, is highly infectious and lethal, and has become an important factor hindering the healthy and sustainable development of aquaculture. Chicken egg yolk antibody (IgY) has the advantages of high antigen specificity, inexpensive and easy to obtain, simple preparation, no toxic side effects, and in line with animal welfare, which is a green and safe alternative to antibiotics. In this study, the potential of specific IgY in the treatment of gastrointestinal pathogens was explored by observing the effects of specific IgY on intestinal flora, pathological tissue, apoptosis, oxidative stress, and inflammatory response of tilapia. We used the specific IgY prepared in the early stage to feed tilapia for 10 days, and then the tilapia was challenged with Streptococcus agalactiae. The results showed that feeding IgY before challenge had a small effect on the intestinal flora, and after challenge specific IgY decreased the proportion of Streptococcus and increased the diversity of the intestinal flora; in histopathology, specific IgY decreased tissue damage and maintained the integrity of tissue structure.Further study found that specific IgY can reduce intestinal epithelial cell apoptosis and reduce caspase activity; at the same time, the content of MDA was decreased, and the activities of SOD, CAT, GSH-Px and GR were increased. In addition, specific IgY can down-regulate the expression levels of IL-8 and TNF-α genes and up-regulate the expression levels of IL-10 and TGF-β. The results of this study showed that specific IgY could improve the intestinal flora of tilapia infected with Streptococcus agalactiae, reduce intestinal cell apoptosis, oxidative stress injury and inflammatory response, thereby reducing tissue damage and protecting the health of tilapia. Overall, specific IgY can be further explored as a potential antibiotic alternative for gastrointestinal pathogen infections.

Preparation of natural high-mannose-type oligosaccharides (Glc1Man9GlcNAc2) with the asparagine-glycine-threonine as consensus sequence from chicken egg yolk

High-mannose-type glycan structure of N-glycoproteins plays important roles in the proper folding of proteins in sorting glycoprotein secretion and degradation of misfolded proteins in the endoplasmic reticulum (ER). The Glc1Man9GlcNAc2 (G1M9)-type N-glycan is one of the most important signaling molecules in the ER. However, current chemical synthesis strategies are laborious, warranting more practical approaches for G1M9-glycopeptide development. Wang et al. reported the procedure to give G1M9-Asn-Fmoc through chemical modifications and purifications from 40 chicken eggs, but only 3.3 mg of G1M9-glycopeptide was obtained. Therefore, better methods are needed to obtain more than 10 mg of G1M9-glycopeptide. In this study, we report the preparation of G1M9-glycopeptide (13.2 mg) linking Asn-Gly-Thr triad as consensus sequence from 40 chicken eggs. In this procedure, λ-carrageenan treatment followed by papain treatment was used to separate the Fc region of IgY antibody that harbors high-mannose glycans. Moreover, cotton hydrophilic interaction liquid chromatography was adapted for easy purification. The resulting G1M9-Asn(Fmoc)-Gly-Thr was identified by nuclear magnetic resonance and mass spectroscopy. G1M9-Asn(Fmoc)-Gly, G1M9-Asn(Fmoc), and G1M9-OH were also detected by mass spectroscopy. Here, our developed G1M9-tripeptide might be useful for the elucidation of glycoprotein functions as well as the specific roles of the consensus sequence.

Protective effect of chicken yolk antibody Y against Campylobacter jejuni induced diarrhea in cats.

Campylobacter jejuni (C. jejuni) is a common pathogen that often causes diarrhea, loss of appetite, and even enteritis in domestic cats, affecting their growth and development, especially in kittens under 6 months of age. Oral passive immunization with chicken yolk antibody Y has been proved effective for the treatment of gastrointestinal pathogen infections due to its high specificity. In this study, C. jejuni was isolated from diarrheal cat feces, and the specific egg yolk antibody Y against C. jejuni was demonstrated to effectively inhibit its proliferation in vitro experiments. To evaluate the effect of anti-C. jejuni IgY, the mouse C. jejuni infection model was established and it was found that IgY could alleviate C. jejuni-induced clinical symptoms. Consistent with these results, the reduction of pro-inflammatory factors and intestinal colonization by C. jejuni in the IgY-treated groups, especially in the high dose group. We then evaluated the protective effect of IgY on young Ragdoll cats infected with C. jejuni. This specific antibody reduced the rate of feline diarrhea, protected the growth of young cats, inhibited systemic inflammatory hyperactivation, and increased fecal short-chain fatty acid concentrations. Notably, IgY may have a protective role by changing intestinal amino acid metabolism and affecting C. jejuni chemotaxis. Collectively, specific IgY is a promising therapeutic strategy for C. jejuni-induced cat diarrhea.

Development of a membrane-disruption assay using phospholipid vesicles as a proxy for the detection of cellular membrane degradation

Snakebite envenoming is a global health issue that affects millions of people worldwide, and that causes morbidity rates surpassing 450,000 individuals annually. Patients suffering from snakebite morbidities may experience permanent disabilities such as pain, blindness and amputations. The (local) tissue damage that causes these life-long morbidities is the result of cell- and tissue-damaging toxins present in the venoms. These compounds belong to a variety of toxin classes and may affect cells in various ways, for example, by affecting the cell membrane. In this study, we have developed a high-throughput in vitro assay that can be used to study membrane disruption caused by snake venoms using phospholipid vesicles from egg yolk as a substrate. Resuspended chicken egg yolk was used to form these vesicles, which were fluorescently stained to allow monitoring of the degradation of egg yolk vesicles on a plate reader. The assay proved to be suitable for studying phospholipid vesicle degradation of crude venoms and was also tested for its applicability for neutralisation studies of varespladib, which is a PLA2 inhibitor. We additionally made an effort to identify the responsible toxins using liquid chromatography, followed by post-column bioassaying and protein identification using high-throughput venomics. We successfully identified various toxins in the venoms of C. rhodostoma and N. mossambica, which are likely to be involved in the observed vesicle-degrading effect. This indicates that the assay can be used for screening the membrane degrading activity of both crude and fractionated venoms as well as for neutralisation studies.