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1.
Int J Biol Macromol ; 259(Pt 2): 129298, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38199555

RESUMO

Seeking safe and environmentally friendly natural immunomodulators is a pressing requirement of humanity. This study investigated the differential binding characteristics of two polar polyphenols (PP), namely epicatechin (EC) and chlorogenic acid (CA), to ovotransferrin (OVT), and explored the relationship between structural transformations and immunomodulatory activity of OVT-PP complexes. Results showed that CA exhibited a stronger affinity for OVT than EC, mainly driven by hydrogen bonds and van der Waals forces. Complexation-induced conformational variations in OVT, including static fluorescence quenching, increased microenvironment polarity surrounding tryptophan and tyrosine residues, and the transition from disordered α-helix to stable ß-sheet. Furthermore, the structural conformation transformation of OVT-PP complexes facilitated the enhancement of immunomodulatory activity, with the OVT-CA (10:2) complex demonstrating the best immunomodulatory activity. Principal component analysis (PCA) and Pearson correlation analysis revealed the immunomodulatory activities of the OVT-PP complexes were influenced by surface hydrophobicity (negatively correlated), ß-sheet percentage and polyphenol binding constants. It could be inferred that PP complexation increased the surface polarity of OVT, consequently enhancing its immunomodulatory activity by promoting cell membrane affinity and antigen recognition. This study provides valuable guidance for effectively utilizing polyphenol-protein complexes in enhancing immunomodulatory activity.


Assuntos
Catequina , Conalbumina , Ácido Clorogênico , Fatores Imunológicos/farmacologia , Polifenóis/farmacologia
2.
J Pediatr (Rio J) ; 100(1): 60-66, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37597532

RESUMO

OBJECTIVE: Evaluate biomarkers capable of safely guiding Yellow fever vaccine (YFV) vaccination among individuals suspicious of hen's egg allergy, and identify factors associated with a higher risk for adverse events after immunization (AEAI). METHODS: Patients underwent skin prick test (SPT) for standardized allergens: whole egg, egg white, egg yolk; YFV (1:10 dilution; Biomanguinhos-Fiocruz), and intradermal test (IDT; YFV 0.02 mL, 1:100 dilution) and positive and negative controls. Serum levels of specific IgE (sIgE) for a whole egg, egg white, egg yolk, egg albumin, ovomucoid, lysozyme, and conalbumin (ImmunoCap®; ThermoFisher®) were obtained. Patients sensitized to YFV were submitted to YFV desensitization, and those negatives received YFV (0.5mL) and remained under surveillance for at least one hour. RESULTS: 103 patients were enrolled, 95% under 12 years old. 71% (81/103) of patients had reactions: 80% immediate, 11% mixed, and 9% delayed. There was an association between positive skin test results with YFV and the severity of the reaction (OR:7.64; 95%CI:1.61-36.32; p = 0,011). Only the presence of sIgE to ovomucoid was associated with clinical symptoms (p = 0,025). Thirty patients underwent the YFV desensitization protocol. CONCLUSION: There is a relationship between the positivity of the egg's components and the severity of the clinical reaction. Furthermore, the relationship between the positivity of the tests with the YFV and egg's components may show a tendency to look at ovomucoid and conalbumin, but it is not a certainty. Therefore, further studies are needed to confirm these associations, and for now, the authors still recommend using the vaccine for testing when necessary.


Assuntos
Hipersensibilidade a Ovo , Febre Amarela , Humanos , Animais , Feminino , Criança , Hipersensibilidade a Ovo/diagnóstico , Ovomucina , Conalbumina , Galinhas , Imunoglobulina E , Vacinação/efeitos adversos , Alérgenos
3.
Int J Biol Macromol ; 253(Pt 3): 126850, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-37703969

RESUMO

Different aggregation morphologies of ovotransferrin (OVT) aggregates were successfully obtained through precise control, and the effects on structural, physical, liquid-liquid and gas-liquid interfacial characteristics as well as mechanisms were explored for the first time. It was observed that the surface hydrophobicity of OVT fibrils was higher than OVT spheres due to the acid-heat treatment. The exploration of liquid-liquid interface behaviors indicated that OVT fibrils possessed higher adsorption capacity at the interface, revealing the higher surface activity at the oil-water interface. During adsorption process, fibrils exhibited higher diffusion rate, while spheres were easier to penetrate and rearrange at the interface. The interfacial film composed of fibrils possessed more elastic solid-like behaviors owing to the higher surface activity of individual fibrous aggregates and rapid fibril-fibril interactions. The analysis of gas-liquid interface characteristics presented that OVT spheres possessed lower interfacial tension and higher interfacial viscoelasticity, and showed significantly higher FC and FS values in comparation to fibrils. These findings will facilitate the reader's understanding of the relationship between protein aggregate structure and properties, and lay a foundation for broadening the application of OVT and even other proteins.


Assuntos
Conalbumina , Tensão Superficial , Adsorção , Viscosidade , Propriedades de Superfície
4.
Mikrochim Acta ; 190(10): 404, 2023 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-37728672

RESUMO

A process-simplified hard template approach was established to synthesize the monodisperse macroporous silica microspheres with homogeneous structures by twice alkali-thermal treatment and calcination routes. Porous vinyl-functionalized polysesquioxane microspheres (V-PMSQ) were synthesized through a hydrolyzation-polycondensation method and used as templates. The template particles with large aperture and high pore volume were obtained by adjusting the pH value and reaction time of the twice alkali-thermal reaction. After calcination, monodisperse silica microspheres with an average pore size of 30 nm, homogeneous pore structures, and narrow particle size distribution were fabricated, which can be directly used as chromatographic matrices without classification. After that, a new reversed-phase/strong anion-exchange (RP/SAX) mixed-mode stationary phase Sil-S-VOIM was prepared by bonding the 1-vinyl-3-octyl-imidazole ligands to the above silica microspheres through a "thiol-ene" click reaction. The performance of the Sil-S-VOIM column was evaluated by one acidic protein (transferrin) and two basic proteins (lysozyme, α-chymotrypsin) and compared to a single imidazole-modified Sil-S-VIM column and an octyl-modified Sil-C8 column, respectively. Due to the synergistic effect of electrostatic repulsion and hydrophobic interactions, baseline separations of the above proteins were observed only on the Sil-S-VOIM column, with resolutions of 2.55 and 2.01 between lysozyme and transferrin, and between transferrin and α-chymotrypsin, respectively, indicating good selectivity and separation ability compared with single-mode stationary phases. It was applied to the isolation of egg white samples with peaks identified by SDS-PAGE and MALDI-TOF-MS. The results showed that the selective retention and isolation of ovomucoid and ovotransferrin were successfully achieved, with yields of 78.8% and 67.2%, respectively. The protocol described in this work is simpler, faster, and has higher protein recovery. Overall, this new mixed-mode stationary phase provided a promising potential for the separation and determination of intact proteins.


Assuntos
Conalbumina , Muramidase , Ovomucina , Imidazóis , Transferrina , Álcalis
5.
Poult Sci ; 102(11): 103011, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37657248

RESUMO

Broilers often suffer from subclinical intestinal health problems of ill-defined etiology, which have a negative impact on performance. Macroscopic and microscopic evaluations can be used to monitor intestinal health, but because these are subjective and time-consuming, respectively, objective and easy-to-measure biomarkers are urgently needed. Fecal biomarkers can potentially be used as noninvasive, objective measures to evaluate gut health in broilers. The aim of the current study was to evaluate ovotransferrin (OVT) as a biomarker in fecal/colonic samples derived from broilers from 27 industrial farms by investigating associations between OVT, broiler performance and gut histology parameters. Eight chickens per farm were randomly selected, weighed and euthanized on d 28 of the production round. A duodenal section was collected to measure the intestinal villus structure (villus length, crypt depth) and the inflammatory status of the gut (CD3+ T-lymphocytes area percentage). The coefficient of variation for the OVT (between farms; 83.45%, within farms; 95.13%) was high compared to the villus length (between farms; 10.91%, within farms; 15.48%), crypt depth (between farms; 15.91%, within farms; 14.10%), villus-to-crypt ratio (between farms; 22.08%, within farms; 20.53%), and CD3+ (between farms; 36.38%, within farms; 26.13%). At farm level, colonic OVT was significantly associated with the average slaughter weight (P = 0.005), daily weight gain (P = 0.007) and the European production index (EPI) (P = 0.009). At broiler level, significant associations were found between colonic OVT and the villus length (P = 0.044) and between the colonic OVT and villus-to-crypt ratio (P = 0.050). These results thus show that quantifying OVT in colon can have merit for evaluation of intestinal health in broilers under field conditions.


Assuntos
Galinhas , Conalbumina , Animais , Mucosa Intestinal , Duodeno , Biomarcadores , Dieta/veterinária , Ração Animal/análise , Suplementos Nutricionais
6.
J Agric Food Chem ; 71(33): 12474-12486, 2023 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-37566483

RESUMO

Ovotransferrin (OVT) has been confirmed to have anti-inflammatory activity. However, its effect and mechanism on gastric inflammation are unclear. In this study, the effect and mechanism of the OVT on the tumor necrosis factor-α (TNF-α) induced inflammatory response in gastric epithelial cells (GES-1) were investigated. The enzyme linked immunosorbent assay (ELISA) was used to determine the levels of inflammation cytokines, followed by RNA sequencing to explore the potential pathways of its anti-inflammatory effect, and then it was validated by Western blotting and pathways inhibitors. Results showed that the OVT at concentrations of 50-400 µg/mL displayed nontoxicity against GES-1 cells. Additionally, 100 µg/mL of OVT obviously reduced the secretion of interleukin (IL)-8, IL-6, and TNF-α by 63.02% (630.09/1703.98), 35.53% (935.81/1451.43), and 36.19% (964.60/1511.63), respectively. The results of RNA sequencing exhibited that the OVT significantly influences the activation of mitogen-activated protein kinase (MAPK) and the nuclear factor kappa-light-chain enhancer of activated B cell (NF-κB) pathways, which was verified by the levels of p-IKK, p-IκB, p-P65, p-ERK, p-JNK, and p-P38 protein. IL-8 contents released by GES-1 cells after incubation with inhibitors of NF-κB and MAPK pathways further confirmed that OVT hindered activation of these two pathways. Collectively, these results suggested that OVT was a natural protein with the potential to treat gastric inflammation.


Assuntos
Proteínas Quinases Ativadas por Mitógeno , NF-kappa B , Humanos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , NF-kappa B/metabolismo , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo , Conalbumina/metabolismo , Células Epiteliais/metabolismo , Inflamação/genética , Inflamação/metabolismo , Anti-Inflamatórios/farmacologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
7.
J Chromatogr A ; 1705: 464208, 2023 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-37453173

RESUMO

The influence of the resin structure, on the competitive binding and separation of a two-component protein mixture with anion exchange resins is evaluated using conalbumin and green fluorescent protein as a model system. Two macroporous resins, one with large open pores and one with smaller pores, are compared to a resin with grafted polymers. Investigations include measurements of single and two-component isotherms, batch uptake kinetics and two-component column breakthrough. On both macroporous resins, the weaker binding protein, conalbumin, is displaced by the stronger binding green fluorescent protein. For the large pore resin, this results in a pronounced overshoot and efficient separation by frontal chromatography. The polymer-grafted resin exhibits superior capacity and kinetics for one-component adsorption, but is unable to achieve separation due to strongly hindered counter-diffusion. Intermediate separation efficiency is obtained with the smaller pore resin. Confocal laser scanning microscopy provides a mechanistic explanation of the underlying intra-particle diffusional phenomena revealing whether unhindered counter-diffusion of the displaced protein can occur or not. This study demonstrates that the resin's intra-particle structure and its effects on diffusional transport are crucial for an efficient separation process. The novelty of this work lies in its comprehensive nature which includes examples of the three most commonly used resin structures: a small pore agarose matrix, a large-pore polymeric matrix, and a polymer grafted resin. Comparison of the protein adsorption properties of these materials provides valuable clues about advantages and disadvantages of each for anion exchange chromatography applications.


Assuntos
Resinas de Troca Aniônica , Conalbumina , Adsorção , Proteínas de Fluorescência Verde , Resinas de Troca Aniônica/química , Polímeros/química , Cromatografia por Troca Iônica , Cinética , Ânions
8.
J Agric Food Chem ; 71(27): 10448-10458, 2023 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-37390300

RESUMO

The eggshell cuticle layer (ECL) and eggshell mineralized layer (EML) contain amounts of glycoproteins and proteoglycans. However, there were few comprehensive reports about the effect of post-translational modifications on protein structure and function which requires investigation. Therefore, we used comparative N-glycoproteomics to study glycoproteins in the ECL and EML. We identified a total of 272 glycoproteins in this experiment and found that glycoproteins located in EML were more than that in ECL. Moreover, they showed distinct functional difference between both layers. As N-glycosylation of ovocleidin-17 and ovocleidin-116 in the EML affected eggshell mineralization, some glycoproteins located in ECL, like ovotransferrin and ovostatin-like, possessed antibacterial activity. The several regulated glycoproteins in the EML may pertain to the regulation of mineralization, while glycosylated proteins in the ECL may contribute to molecular adhesion and defense against microbial invasion. This study provides new insights into the eggshell matrix protein contents of the ECL and EML.


Assuntos
Galinhas , Casca de Ovo , Animais , Casca de Ovo/química , Casca de Ovo/metabolismo , Galinhas/metabolismo , Conalbumina/metabolismo , Proteoglicanas , Glicoproteínas/metabolismo
9.
Food Chem ; 403: 134353, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36179637

RESUMO

Egg proteins, as one of the most abundant animal protein sources, have received considerable attention for developing delivery systems. Among all egg proteins, egg white (ovalbumin) is the most promising encapsulant due to its excellent properties such as gelling, digestibility, self-assembly, amphiphilic nature. In this review paper, we focused particularly on egg protein-based delivery systems with superior encapsulation and delivery functions, including polymeric nanoparticles, emulsions, hydrogels and aerogels. Egg protein-based delivery systems across a wide range of geometry and dimensions have been applied to protect or control-release bioactive small molecules and macromolecules, probiotics and metal nanostructures. However, there are challenges that must be carefully addressed for advancing the practical applications of egg protein-based delivery system in foods, including allergenicity from ovalbumin and ovotransferrin, intolerance to environmental conditions, limited processing technologies. More efforts are warranted to fill knowledge gaps related to fabrication, utilization and digestive mechanisms of egg protein-derived delivery systems.


Assuntos
Proteínas do Ovo , Clara de Ovo , Animais , Ovalbumina/química , Proteínas do Ovo/química , Clara de Ovo/química , Conalbumina/química , Hidrogéis
10.
Int J Biol Macromol ; 229: 268-281, 2023 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-36581036

RESUMO

In this study, ovotransferrin/chitosan (OVT/CS) composite films cross-linked by citric acid (CA) were prepared and the effects of CA cross-linking on the structure and physicochemical properties of the composite films were investigated. The cross-linking degree measured by 2,4,6-trinitrobenzenesulfonic acid (TNBS) method confirmed that CA was cross-linked with the matrix, and Fourier transform infrared spectroscopy confirmed that more hydrogen bonds and electrostatic interactions were formed between CA and the matrix. Differential scanning calorimetry, X-ray diffraction and Scanning electron microscope images revealed the compatibility between substances. The synergistic inhibition between the matrix results in a significantly higher antibacterial activity of the composite film than the pure film. Compared with uncross-linked films, the mechanical properties, barrier properties and water resistance of the cross-linked films were significantly improved. When the concentration of CA was 5 wt% (W/W, on a dry basis of the weight of OVT and CS), the most significant improvement in film performance was obtained. The tensile strength of the film increased from 32.05 MPa without cross-linking to 61.99 MPa and the swelling degree decreased from 51.5 % to 24.23 %. The observed phenomena suggest that cross-linking OVT and CS with CA can obtain functional edible films with improved properties.


Assuntos
Quitosana , Quitosana/química , Conalbumina , Ácido Cítrico/química , Resistência à Tração , Água/química , Espectroscopia de Infravermelho com Transformada de Fourier , Embalagem de Alimentos
11.
Food Chem ; 409: 135281, 2023 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-36586251

RESUMO

The effects of transglutaminase (TGase, 1.0 unit/mL) with heat (95 °C, 5 min), 2-mercaptoethanol (2-ME, 0.83 %), and l-cysteine (l-Cys, 50 mM) pretreatment on the cross-linking of ovalbumin (OVA) and ovotransferrin (OVT) were investigated. SDS-PAGE revealed that although the polymerization of OVA and OVT did not occur after 3 h of incubation at 40 °C with TGase, OVA polymerized into high molecular weight polymers following TGase with 2-ME and heat pretreatment after 3 h of incubation. The surface hydrophobicity and reactive sulfhydryl (SH) groups of OVA samples significantly increased from 4065.7 ± 136.7 and 89.3 ± 1.2 SH groups (µmol/g) to 31483.6 ± 342.7 and 119.5 ± 3.7 SH groups (µmol/g), respectively. Similar results were obtained for OVT with TGase and l-Cys pretreatment and a 3-h incubation at 40 °C. The use of TGase, a reducing agent, and/or heat pretreatment can be used for the polymerization of OVA and OVT.


Assuntos
Substâncias Redutoras , Transglutaminases , Ovalbumina , Transglutaminases/metabolismo , Conalbumina , Temperatura Alta , Mercaptoetanol
12.
Food Chem ; 404(Pt A): 134533, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36444011

RESUMO

Radiofrequency (RF) assisted thermal processing can significantly enhance the gel firmness of egg white powder compared to the traditional hot room (HR) processing. Thus, the present study aims to delineate the impact of RF processing on the proteins' structure and bio-functional properties of egg white protein gels. The secondary protein conformations of egg white proteins exhibited no significant alteration upon RF-assisted thermal processing over traditional HR processing. In-vitro gastrointestinal (GI) digestion of egg white gels demonstrated that the RF processing did not compromise the accessibility of digestive proteases despite a more robust gel network. Peptides from the GI digest of egg white gel showed that Ovalbumin and Ovotransferrin were the parent proteins of most of the unique peptides generated, and minor structural differences accounted for these peptides. The bioavailability of the egg protein-derived peptides remains unaffected after RF processing without compromising the viability and integrity of the GI epithelial cells.


Assuntos
Conalbumina , Proteínas do Ovo , Ondas de Rádio , Ovalbumina , Ovos
13.
Food Funct ; 14(1): 305-318, 2023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-36503960

RESUMO

Acute gastric mucosal injury is a common gastrointestinal disorder, which influences patients' life quality. It was found that ovotransferrin (OVT) reduces the abundance of Helicobacter pylori associated with gastric disease in the intestine of immunosuppressed mice. To clarify its gastric protective function, the present study investigated the effect of OVT on BALB/c mice with ethanol-induced gastric mucosal injury. Results showed that OVT attenuated the ethanol-induced gastric mucosal injury. Furthermore, OVT effectively downregulated the expression of inflammatory markers (tumor necrosis factor-α, interleukin (IL)-1ß and IL-6) but enhanced the secretion of IL-4, IL-10 and prostaglandin E2. And OVT pretreatment significantly inhibited the activation of the MAPK/NF-κB pathway. Additionally, OVT improved gastric antioxidant ability by increasing superoxide dismutase and glutathione levels and decreasing malondialdehyde and myeloperoxidase content. Pretreatment with OVT modulated the equilibrium between B-cell lymphoma-2 (Bcl-2) and Bcl-2-associated X. The above results indicated that OVT alleviated inflammatory responses, oxidative stress and apoptosis in gastric mucosal injury mice caused by ethanol.


Assuntos
Gastropatias , Úlcera Gástrica , Camundongos , Animais , Etanol/metabolismo , Conalbumina/farmacologia , Camundongos Endogâmicos BALB C , Gastropatias/induzido quimicamente , Mucosa Gástrica/metabolismo , Estresse Oxidativo , NF-kappa B/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Úlcera Gástrica/induzido quimicamente
14.
Food Chem ; 405(Pt B): 135019, 2023 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-36436239

RESUMO

Ovotransferrin is the most heat-sensitive protein in egg white which alters the processing suitability. To improve thermostability, phosphorylation modification was performed under different pH values (5.0, 6.0, 7.0, 8.0, and 9.0), and the reasons for which were explored via physicochemical changes in this study. SEM and particle size results showed that phosphorylation diminished the average particle diameter and the number of attached particles. CD results revealed that the α-helix content of phosphorylated ovotransferrin increased and the random coil decreased significantly (P < 0.05). Tertiary structure, surface hydrophobicity and ζ-potential analyses showed that phosphorylation made more hydrophobic amino acids buried inside ovotransferrin. These changes might be because most of the phosphorylation occurred in α-helix and ß- sheet to promote the thermal tolerance of phosphorylated ovotransferrin by improving its structure orderliness and decreasing surface hydrophobicity. The results indicated that phosphorylation was a practical method to enhance the thermal stability of heat-sensitive ovotransferrin.


Assuntos
Conalbumina , Pasteurização , Fosforilação , Clara de Ovo , Aminoácidos
15.
J Agric Food Chem ; 70(44): 14170-14178, 2022 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-36317732

RESUMO

Tripeptide IRW derived from egg ovotransferrin was initially identified to be an inhibitor of angiotensin-converting enzyme. Later, IRW has been shown to possess various bioactivities, including anti-inflammatory activity and the ability to suppress colitis development. Nevertheless, its role in protecting intestinal barrier integrity has not been reported. This study aims to investigate the effect of IRW on inhibiting intestinal barrier dysfunction and inflammation in lipopolysaccharide (LPS)-treated Caco-2 cells. Pretreatment with IRW could mitigate the LPS-induced reduction of transepithelial electronic resistance values and decrease the paracellular permeation of differentiated Caco-2 cell monolayers. Meanwhile, IRW restored the expression level and cell surface distribution of the tight junction protein occludin. Furthermore, IRW showed LPS-neutralizing activity and could significantly inhibit LPS-induced activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways. In conclusion, our study demonstrated the ability of IRW to prevent LPS-induced intestinal barrier dysfunction and prohibit inflammatory responses.


Assuntos
Conalbumina , Lipopolissacarídeos , Humanos , Conalbumina/farmacologia , Conalbumina/metabolismo , Células CACO-2 , Lipopolissacarídeos/farmacologia , Proteínas do Ovo/farmacologia , Proteínas do Ovo/metabolismo , Inflamação/induzido quimicamente , Inflamação/tratamento farmacológico , Inflamação/metabolismo , NF-kappa B/genética , NF-kappa B/metabolismo , Mucosa Intestinal/metabolismo , Junções Íntimas/metabolismo
16.
Food Microbiol ; 107: 104068, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35953175

RESUMO

The importance of egg natural defences to prevent bacterial contamination and their relation with hen age in extended production cycles were evaluated. Egg-white from eggs of different hen age groups (up 100-weeks-old) and lines (Hy-Line white and brown) were inoculated with Gram-positive Staphylococcus aureus or Gram-negative Salmonella Typhimurium, ranging from 103-106 CFU/mL. Our results show that concentrations of egg-white lysozyme and, particularly, ovotransferrin are important to modulate bacterial survival in a dose-dependent matter. Depending on protein concentration, their effect ranges from bactericidal to bacteriostatic, with a threshold for bacterial contamination that depends also on hen age and line. The concentrations of lysozyme and ovotransferrin increased with hen age (up to 2 and 22 w/w% of total protein, respectively), and eggs laid by older hens exhibited the greatest potential to prevent the growth of the highest Salmonella inoculum (106 CFU/mL). Salmonella-penetration experiments demonstrated that non-contaminated eggs display significantly higher concentrations of antimicrobial proteins. However, eggs from older hens needed a higher concentration of these proteins (>20% ovotransferrin) to prevent bacterial contamination, showing that antimicrobial protein concentrations in egg-whites was not the only factor influencing bacterial contamination. Finally, this study demonstrated that egg-white of eggs produced by old hens are less prone to contamination by Salmonella.


Assuntos
Galinhas , Clara de Ovo , Animais , Antibacterianos/farmacologia , Bactérias , Galinhas/microbiologia , Conalbumina/farmacologia , Ovos/microbiologia , Feminino , Muramidase/farmacologia
17.
Integr Comp Biol ; 62(6): 1584-1594, 2022 12 30.
Artigo em Inglês | MEDLINE | ID: mdl-35675319

RESUMO

When animals are sick, their physiology and behavior change in ways that can impact their offspring. Research is emerging showing that infection risk alone can also modify the physiology and behavior of healthy animals. If physiological responses to environments with high infection risk take place during reproduction, it is possible that they lead to maternal effects. Understanding whether and how high infection risk triggers maternal effects is important to elucidate how the impacts of infectious agents extend beyond infected individuals and how, in this way, they are even stronger evolutionary forces than already considered. Here, to evaluate the effects of infection risk on maternal responses, we exposed healthy female Japanese quail to either an immune-challenged (lipopolysaccharide [LPS] treated) mate or to a healthy (control) mate. We first assessed how females responded behaviorally to these treatments. Exposure to an immune-challenged or control male was immediately followed by exposure to a healthy male, to determine whether treatment affected paternity allocation. We predicted that females paired with immune-challenged males would avoid and show aggression towards those males, and that paternity would be skewed towards the healthy male. After mating, we collected eggs over a 5-day period. As an additional control, we collected eggs from immune-challenged females mated to healthy males. We tested eggs for fertilization status, embryo sex ratio, as well as albumen corticosterone, lysozyme activity, and ovotransferrin, and yolk antioxidant capacity. We predicted that immune-challenged females would show the strongest changes in the egg and embryo metrics, and that females exposed to immune-challenged males would show intermediate responses. Contrary to our predictions, we found no avoidance of immune-challenged males and no differences in terms of paternity allocation. Immune-challenged females laid fewer eggs, with an almost bimodal distribution of sex ratio for embryos. In this group, albumen ovotransferrin was the lowest, and yolk antioxidant capacity decreased over time, while it increased in the other treatments. No differences in albumen lysozyme were found. Both females that were immune-challenged and those exposed to immune-challenged males deposited progressively more corticosterone in their eggs over time, a pattern opposed to that shown by females exposed to control males. Our results suggest that egg-laying Japanese quail may be able to respond to infection risk, but that additional or prolonged sickness symptoms may be needed for more extensive maternal responses.


Assuntos
Coturnix , Muramidase , Feminino , Masculino , Animais , Coturnix/fisiologia , Corticosterona , Antioxidantes , Conalbumina
18.
Ultrason Sonochem ; 84: 105958, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35220178

RESUMO

Ovotransferrin (OVT) is one of the major functional proteins in egg white protein. Most of the industry only paid attention the biological activity of OVT in iron supplement, antibacterial and other aspects, few reports were carried out on its processing characteristics such as foaming, interfacial behavior such as emulsification and foaming, which was an important processing functional attribute affecting its application scenario. In this study, the effects of ultrasound-assisted glycosylation on the interface and foaming characteristics of OVT were investigated. The results showed that proper ultrasonic treatment had a significant effect on the structure and physicochemical properties of OVT glycosylation products. When ultrasonic treatment lasted for 20 min, the grafting degree of OVT was 20.98%, the particle size decreased and the absolute value of potential increased. The foaming ability of OVT increased first and then decreased after ultrasonic-assisted glycosylation treatment. The foaming ability of OVT increased from 43.54% to 96.73% and the foaming stability increased from 68.92% to 89.19% after ultrasonic-assisted glycosylation treatment for 20 min. The experimental study effectively discovered the effect of ultrasound-assisted glycosylation on the foaming property of OVT, and would provide important technical references for expanding its application in food, biology, medicine and other fields.


Assuntos
Antibacterianos , Conalbumina , Conalbumina/química , Conalbumina/farmacologia , Glicosilação , Tamanho da Partícula
19.
ACS Biomater Sci Eng ; 8(1): 109-118, 2022 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-34936344

RESUMO

Antibiotic-resistant pathogens are a serious threat to global public health. The emergence of drug-resistant pathogens is due to the improper use of antibiotics, making the treatment of bacterial infections very challenging. Here, we reported an efficient antibiotic delivery nanoparticle to minimize antibiotic resistance. The nanoparticle was designed to target the bacterial membrane using mesoporous silica nanoparticles (MSNs) modified with an ovotransferrin-derived antimicrobial peptide (OVTp12), enabling the antibiotic to be delivered to the vicinity of the pathogenic bacteria. Moreover, we observed that OVTp12-modified nanoparticles effectively inhibited the growth of Escherichia coliin vitro and in vivo. The nanoparticle with high biosafety could significantly downregulate the expression of inflammation-related cytokines in infected tissues. Thus, this novel bacterial targeted nanoparticle provides advantages in minimizing bacterial drug resistance and treating bacterial infection.


Assuntos
Infecções Bacterianas , Nanopartículas , Antibacterianos/farmacologia , Peptídeos Antimicrobianos , Infecções Bacterianas/tratamento farmacológico , Conalbumina , Humanos , Dióxido de Silício
20.
Food Chem ; 366: 130596, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34293545

RESUMO

Clarification of the mechanism of heat-induced gel formation by proteins under natural food systems could provide important references for the regulation of food texture. In the present study, the proteins involved in the early stage (heating at 72 °C for 8 min) of egg-white thermal gel (EWG) formation were studied quantitatively through comparative proteomic analysis. We discovered that the abundance of ovalbumin and ovomucoid increased significantly (p < 0.01), whereas that of ovotransferrin, lysozyme, ovomucin (mucin 5B and mucin 6) decreased significantly (p < 0.01), in the supernatant of EWG. If the initial interaction of egg white proteins was altered by ultrasonic pretreatment, the abundance of ovomucin and lysozyme in the supernatant of EWG increased, and was accompanied by the change from a solid gel to a fluid gel. Based on these results, we hypothesize that ovomucin has a key role in the formation and regulation of EWG properties.


Assuntos
Ovomucina , Proteômica , Animais , Galinhas , Conalbumina , Proteínas do Ovo , Ovalbumina
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