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Anne B. Mason - One of the best experts on this subject based on the ideXlab platform.
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Monoclonal antibodies to chicken Ovotransferrin: epitopic and phylogenetic analysis
Comparative Biochemistry and Physiology Part A: Physiology, 1995Co-Authors: Anne B. Mason, Chantal J. Kenney, Michael K. Miller, Robert C. Woodworth, Kokila J. Patel, Robert W. EvansAbstract:Abstract 1. The ability of four domain-specific anti-chicken Ovotransferrin antibodies to bind to turkey, quail, duck, pheasant and goose Ovotransferrins was examined directly by an enzyme-linked immunoassay and indirectly in a competitive radioimmunoassay. 2. The ability of these same Ovotransferrins to compete with radioiodinated chicken Ovotransferrin for binding to transferrin receptors on chick embryo red blood cells was also tested. 3. The hypothesis that evolutionarily conserved determinants involved in receptor recognition can be predicted by monoclonal antibodies that block binding of Ovotransferrin to receptor was found to be incorrect.
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A highly conserved surface loop in the C-terminal domain of Ovotransferrin (residues 570-584) is remote from the receptor-binding site.
The Biochemical journal, 1990Co-Authors: Anne B. Mason, Stephen Brown, William R. ChurchAbstract:A peptide corresponding to a surface loop in the C-terminal domain of chicken Ovotransferrin (residues 570-584) was made by solid-phase synthesis and used to immunize rabbits. A 15-amino acid-residue disulphide-linked loop occurs in both domains of all five transferrins for which the sequence is available and lies on the opposite side of the iron-binding site from the interdomain cleft. Polyclonal antibodies to the peptide were specific for non-reduced holo-Ovotransferrin and the C-terminal domain, as shown by e.l.i.s.a. and immunoblotting. The antibody did not inhibit binding of Ovotransferrin to receptors on chick-embryo reticulocytes but was able to bind Ovotransferrin bound to the cellular receptors at 0 degree C. The loop composed of residues 570-584 appears to be remote from the transferrin receptor-binding site.
Giovanni Antonini - One of the best experts on this subject based on the ideXlab platform.
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The Nutraceutical Properties of Ovotransferrin and Its Potential Utilization as a Functional Food.
Nutrients, 2015Co-Authors: Francesco Giansanti, Loris Leboffe, Francesco Angelucci, Giovanni AntoniniAbstract:Ovotransferrin or conalbumin belong to the transferrin protein family and is endowed with both iron-transfer and protective activities. In addition to its well-known antibacterial properties, Ovotransferrin displays other protective roles similar to those already ascertained for the homologous mammalian lactoferrin. These additional functions, in many cases not directly related to iron binding, are also displayed by the peptides derived from partial hydrolysis of Ovotransferrin, suggesting a direct relationship between egg consumption and human health.
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Physiological roles of Ovotransferrin
Biochimica et biophysica acta, 2011Co-Authors: Francesco Giansanti, Loris Leboffe, Giuseppina Pitari, Rodolfo Ippoliti, Giovanni AntoniniAbstract:Abstract Background Ovotransferrin is an iron-binding glycoprotein, found in avian egg white and in avian serum, belonging to the family of transferrin iron-binding glycoproteins. All transferrins show high sequence homology. In mammals are presents two different soluble glycoproteins with different functions: i) serum transferrin that is present in plasma and committed to iron transport and iron delivery to cells and ii) lactoferrin that is present in extracellular fluids and in specific granules of polymorphonuclear lymphocytes and committed to the so-called natural immunity. To the contrary, in birds, Ovotransferrin remained the only soluble glycoprotein of the transferrin family present both in plasma and egg white. Scope of review Substantial experimental evidences are summarized, illustrating the multiple physiological roles of Ovotransferrin in an attempt to overcome the common belief that Ovotransferrin is a protein dedicated only to iron transport and to iron withholding antibacterial activity. Major conclusions Similarly to the better known family member protein lactoferrin, Ovotransferrin appears to be a multi-functional protein with a major role in avian natural immunity. General significance Biotechnological applications of Ovotransferrin and Ovotransferrin-related peptides could be considered in the near future, stimulating further research on this remarkable protein. This article is part of a Special Issue entitled Transferrins: Molecular mechanisms of iron transport and disorders.
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Ovotransferrin expression and release by chicken cell lines infected with Marek's disease virus.
Biochemistry and cell biology = Biochimie et biologie cellulaire, 2007Co-Authors: Francesco Giansanti, M. Federica Giardim.f. Giardi, M. Teresa Massuccim.t. Massucci, Dario Botti, Giovanni AntoniniAbstract:Mammals posses both serum transferrin and lactoferrin, whose functions are taken over in birds by Ovotransferrin, displaying both iron transport and antibacterial activities. Ovotransferrin also exerts antiviral activity towards Marek’s disease virus, an avian member of the herpes family of viruses. This virus infects lymphoid organs and induces the transcription of Ovotransferrin in infected chicken embryo fibroblasts. However, it has not yet been established whether Ovotransferrin gene transcription is linked to the release of the protein outside the cells or whether Ovotransferrin expression and release also occurs in chicken lymphoblastoid cells in which the Marek’s disease viral genome is integrated. Our results indicate that both serum and egg-white isoforms of Ovotransferrin are expressed and released in the supernatants of chicken embryo fibroblast and lymphoblastoid cells in the absence of infection. Viral infection of chicken embryo fibroblasts caused a slight increase of Ovotransferrin release,...
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Antiviral activity of Ovotransferrin discloses an evolutionary strategy for the defensive activities of lactoferrin
Biochemistry and cell biology = Biochimie et biologie cellulaire, 2002Co-Authors: Francesco Giansanti, Giovanni Antonini, M. Teresa Massuccim.t. Massucci, Dario Botti, P. Valenti, Paola Rossi, Lucilla SegantiAbstract:Ovotransferrin (formerly conalbumin) is an iron-binding protein present in birds. It belongs to the transferrin family and shows about 50% sequence homology with mammalian serum transferrin and lactoferrin. This protein has been demonstrated to be capable of delivering iron to cells and of inhibiting bacterial multiplication. However, no antiviral activity has been reported for Ovotransferrin, although the antiviral activity of human and bovine lactoferrins against several viruses, including human herpes simplex viruses, has been well established. In this report, the antiviral activity of Ovotransferrin towards chicken embryo fibroblast infection by Marek's disease virus (MDV), an avian herpesvirus, was clearly demonstrated. Ovotransferrin was more effective than human and bovine lactoferrins in inhibiting MDV infection and no correlation between antiviral efficacy and iron saturation was found. The observations reported here are of interest from an evolutionary point of view since it is likely that the d...
William R. Church - One of the best experts on this subject based on the ideXlab platform.
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A highly conserved surface loop in the C-terminal domain of Ovotransferrin (residues 570-584) is remote from the receptor-binding site.
The Biochemical journal, 1990Co-Authors: Anne B. Mason, Stephen Brown, William R. ChurchAbstract:A peptide corresponding to a surface loop in the C-terminal domain of chicken Ovotransferrin (residues 570-584) was made by solid-phase synthesis and used to immunize rabbits. A 15-amino acid-residue disulphide-linked loop occurs in both domains of all five transferrins for which the sequence is available and lies on the opposite side of the iron-binding site from the interdomain cleft. Polyclonal antibodies to the peptide were specific for non-reduced holo-Ovotransferrin and the C-terminal domain, as shown by e.l.i.s.a. and immunoblotting. The antibody did not inhibit binding of Ovotransferrin to receptors on chick-embryo reticulocytes but was able to bind Ovotransferrin bound to the cellular receptors at 0 degree C. The loop composed of residues 570-584 appears to be remote from the transferrin receptor-binding site.
Nan Shang - One of the best experts on this subject based on the ideXlab platform.
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Ovotransferrin Exhibits Osteogenic Activity Partially via Low-Density Lipoprotein Receptor-Related Protein 1 (LRP1) Activation in MC3T3-E1 Cells.
Journal of agricultural and food chemistry, 2020Co-Authors: Nan Shang, Khushwant S. BhullarAbstract:Ovotransferrin, a major protein in egg white, induces osteoblast proliferation and survival in vitro. However, it is unclear which receptor(s) drive the beneficial activities of this bioactive glycoprotein. We examined the role of the low-density lipoprotein receptor-related protein 1 (LRP1) in the actions of Ovotransferrin on osteoblasts. Here, we showed that LRP1 in part regulates osteogenic action of Ovotransferrin. Mouse osteoblasts, MC3T3-E1, with LRP1 deletion displayed diminished osteogenic activity. Our findings indicate that the bone-stimulatory impact of Ovotransferrin on RUNX2, COL1A2, and Ca2+ signaling is LRP1-dependent. This shows that LRP1 not only acts as a scavenger receptor but also participates in Ovotransferrin-mediated gene transcription. However, some of the key bone formatting factors such as ALP synthesis and serine residue phosphorylation of Akt by Ovotransferrin remained independent of LRP1. Overall, this study shows that LRP1-Ovotransferrin interaction might underline in part the ability of Ovotransferrin to promote bone formation.
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Egg White Ovotransferrin Attenuates RANKL-Induced Osteoclastogenesis and Bone Resorption.
Nutrients, 2019Co-Authors: Nan ShangAbstract:Ovotransferrin, a member of the transferrin family, is the second main protein found in egg white. Ovotransferrin was reported to have antimicrobial, antioxidant, and immunomodulating activities. The aim of this work was to characterize the cellular and molecular functions of egg white Ovotransferrin on osteoclasts differentiation and function. Osteoclasts were prepared from mouse macrophage RAW 264.7 cells stimulated with receptor activator of nuclear factor κB ligand (RANKL). Ovotransferrin inhibited osteoclasts differentiation and the calcium–phosphate resorptive ability via the suppression of RANKL-induced nuclear factor κ-light chain-enhancer of activated B cells (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways. Ovotransferrin induced apoptosis of matured osteoclasts, accompanied by increased expression of Bcl-2-like protein 11 (Bim) and Bcl-2-assoicated death promoter (Bad), but decreased expression of B-cell lymphoma 2 (Bcl-2) and B-cell lymphoma-extra-large (Bcl-xl). We established a novel role of egg white Ovotransferrin as an inhibitor of osteoclastogenesis, which may be used for the prevention of osteoporosis.
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Egg White Ovotransferrin Shows Osteogenic Activity in Osteoblast Cells.
Journal of agricultural and food chemistry, 2018Co-Authors: Nan ShangAbstract:Ovotransferrin, the major protein in egg white, is a member of transferrin family. The objective of this study was to study the effects of Ovotransferrin on cell proliferation, differentiation, mineralization and osteoclastogenesis of bone osteoblast cells. Effect of Ovotransferrin (concentrations ranging from 1 to 1000 μg/mL) on the proliferation, differentiation, and mineralization of mouse osteoblast cells MC3T3-E1 was determined by 5-bromo-2-deoxyuridine (BrdU) incorporation assay, Western blot, immunofluorescence, and Alizarin-S red staining, respectively. Our results showed that Ovotransferrin stimulated cell proliferation (enhanced BrdU incorporation), differentiation (enhanced expression of alkaline phosphatase and type-I collagen), and mineralization (increased calcium deposits) in a dose-dependent manner. Furthermore, Ovotransferrin could increase the expression of osteoprotegerin (OPG) while decreasing the expression of receptor activator of nuclear factor kappa-B ligand (RANKL), suggesting its...
Francesco Giansanti - One of the best experts on this subject based on the ideXlab platform.
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The Nutraceutical Properties of Ovotransferrin and Its Potential Utilization as a Functional Food.
Nutrients, 2015Co-Authors: Francesco Giansanti, Loris Leboffe, Francesco Angelucci, Giovanni AntoniniAbstract:Ovotransferrin or conalbumin belong to the transferrin protein family and is endowed with both iron-transfer and protective activities. In addition to its well-known antibacterial properties, Ovotransferrin displays other protective roles similar to those already ascertained for the homologous mammalian lactoferrin. These additional functions, in many cases not directly related to iron binding, are also displayed by the peptides derived from partial hydrolysis of Ovotransferrin, suggesting a direct relationship between egg consumption and human health.
-
Physiological roles of Ovotransferrin
Biochimica et biophysica acta, 2011Co-Authors: Francesco Giansanti, Loris Leboffe, Giuseppina Pitari, Rodolfo Ippoliti, Giovanni AntoniniAbstract:Abstract Background Ovotransferrin is an iron-binding glycoprotein, found in avian egg white and in avian serum, belonging to the family of transferrin iron-binding glycoproteins. All transferrins show high sequence homology. In mammals are presents two different soluble glycoproteins with different functions: i) serum transferrin that is present in plasma and committed to iron transport and iron delivery to cells and ii) lactoferrin that is present in extracellular fluids and in specific granules of polymorphonuclear lymphocytes and committed to the so-called natural immunity. To the contrary, in birds, Ovotransferrin remained the only soluble glycoprotein of the transferrin family present both in plasma and egg white. Scope of review Substantial experimental evidences are summarized, illustrating the multiple physiological roles of Ovotransferrin in an attempt to overcome the common belief that Ovotransferrin is a protein dedicated only to iron transport and to iron withholding antibacterial activity. Major conclusions Similarly to the better known family member protein lactoferrin, Ovotransferrin appears to be a multi-functional protein with a major role in avian natural immunity. General significance Biotechnological applications of Ovotransferrin and Ovotransferrin-related peptides could be considered in the near future, stimulating further research on this remarkable protein. This article is part of a Special Issue entitled Transferrins: Molecular mechanisms of iron transport and disorders.
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Ovotransferrin expression and release by chicken cell lines infected with Marek's disease virus.
Biochemistry and cell biology = Biochimie et biologie cellulaire, 2007Co-Authors: Francesco Giansanti, M. Federica Giardim.f. Giardi, M. Teresa Massuccim.t. Massucci, Dario Botti, Giovanni AntoniniAbstract:Mammals posses both serum transferrin and lactoferrin, whose functions are taken over in birds by Ovotransferrin, displaying both iron transport and antibacterial activities. Ovotransferrin also exerts antiviral activity towards Marek’s disease virus, an avian member of the herpes family of viruses. This virus infects lymphoid organs and induces the transcription of Ovotransferrin in infected chicken embryo fibroblasts. However, it has not yet been established whether Ovotransferrin gene transcription is linked to the release of the protein outside the cells or whether Ovotransferrin expression and release also occurs in chicken lymphoblastoid cells in which the Marek’s disease viral genome is integrated. Our results indicate that both serum and egg-white isoforms of Ovotransferrin are expressed and released in the supernatants of chicken embryo fibroblast and lymphoblastoid cells in the absence of infection. Viral infection of chicken embryo fibroblasts caused a slight increase of Ovotransferrin release,...
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Antiviral activity of Ovotransferrin discloses an evolutionary strategy for the defensive activities of lactoferrin
Biochemistry and cell biology = Biochimie et biologie cellulaire, 2002Co-Authors: Francesco Giansanti, Giovanni Antonini, M. Teresa Massuccim.t. Massucci, Dario Botti, P. Valenti, Paola Rossi, Lucilla SegantiAbstract:Ovotransferrin (formerly conalbumin) is an iron-binding protein present in birds. It belongs to the transferrin family and shows about 50% sequence homology with mammalian serum transferrin and lactoferrin. This protein has been demonstrated to be capable of delivering iron to cells and of inhibiting bacterial multiplication. However, no antiviral activity has been reported for Ovotransferrin, although the antiviral activity of human and bovine lactoferrins against several viruses, including human herpes simplex viruses, has been well established. In this report, the antiviral activity of Ovotransferrin towards chicken embryo fibroblast infection by Marek's disease virus (MDV), an avian herpesvirus, was clearly demonstrated. Ovotransferrin was more effective than human and bovine lactoferrins in inhibiting MDV infection and no correlation between antiviral efficacy and iron saturation was found. The observations reported here are of interest from an evolutionary point of view since it is likely that the d...
