1. Phosvitin-calcium aggregation and organization at the air-water interface
- Author
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Corinne Belhomme, Véronique Vié, Elisabeth David-Briand, Marc Anton, Catherine Guérin-Dubiard, Unité de recherche sur les Biopolymères, Interactions Assemblages (BIA), Institut National de la Recherche Agronomique (INRA), AGROCAMPUS OUEST, Biophysique, Institut de Physique de Rennes (IPR), Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS), INRA, Région Pays de la Loire, Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS), Science et Technologie du Lait et de l'Oeuf (STLO), Institut National de la Recherche Agronomique (INRA)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)
- Subjects
02 engineering and technology ,Surface pressure ,Microscopy, Atomic Force ,OLIGOELEMENT ,Atomic force microscopy ,Colloid and Surface Chemistry ,MESH: Egg Yolk ,[SDV.IDA]Life Sciences [q-bio]/Food engineering ,MESH: Animals ,Air-water interface ,PROTEINE ANIMALE ,MESH: Microscopy, Atomic Force ,Air ,MESH: Chickens ,Charge density ,Spread film ,04 agricultural and veterinary sciences ,Surfaces and Interfaces ,General Medicine ,MESH: Phosvitin ,021001 nanoscience & nanotechnology ,040401 food science ,Egg Yolk ,INTERFACE ,Phosvitin ,Solutions ,MESH: Calcium ,MICROSCOPIE ,[SDV.IDA.SMA]Life Sciences [q-bio]/Food engineering/domain_sdv.ida.sma ,0210 nano-technology ,Biotechnology ,OEUF ,chemistry.chemical_element ,Calcium ,MESH: Solutions ,Ion ,Aggregation ,0404 agricultural biotechnology ,Adsorption ,PHOSVITIN ,PROTEINE ,MESH: Water ,Molecule ,Animals ,[SPI.GPROC]Engineering Sciences [physics]/Chemical and Process Engineering ,Physical and Theoretical Chemistry ,Aqueous two-phase system ,Water ,Crystallography ,MESH: Air ,chemistry ,Chemical engineering ,Chickens - Abstract
International audience; Phosvitin, an egg yolk protein constituted by 50% of phosphorylated serines, presents good emulsifying properties whereas its interfacial properties are not yet clearly elucidated and remain object of discussion. Phosvitin has a high charge density and naturally forms aggregates through phosphocalcic bridges in egg yolk. This high charge density, doubled by this capacity to aggregate, limits the adsorption of the protein at the air-water interface. In this work, we investigated the aggregation impact by calcium ions on the organization of the phosvitin interfacial film using the atomic force microscopy. Phosvitin interfacial films without calcium ions are compared to phosvitin interfacial films formed in the presence of calcium ions in the subphase. We demonstrated that phosvitin is able to anchor at air-water interfaces in spite of its numerous negative charges. In the compression isotherm a transition was observed just before 28 mN/m signifying a possible modification of the interfacial film structure or organization. Calcium ions induce a reorganization towards a greater compaction of the phosvitin interfacial film even at low surface pressure. In conclusion we suggest that, in diluted regime, phosvitin molecules could adsorb by their two hydrophobic extremities exhibiting loops in the aqueous phase, whereas in concentred regime (high interfacial concentration) it would be adsorbed at the interface by only one extremity (brush model).
- Published
- 2007
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