Reversible self-association of ovalbumin at air-water interfaces and the consequences for the exerted surface pressure
article
In this study the relation between the ability of protein self-association and the surface properties at air-water interfaces is investigated using a combination of spectroscopic techniques. Three forms of chicken egg ovalbumin were obtained with different self-associating behavior: native ovalbumin, heat-treated ovalbumin-being a cluster of 12-16 predominantly noncovalently bound proteins, and succinylated ovalbumin, as a form with diminished aggregation properties due to increased electrostatic repulsion. While the bulk diffusion of aggregated protein is clearly slower compared to monomeric protein, the efficiency of transport to the interface is increased, just like the efficiency of sticking to rather than bouncing from the interface. On a timescale of hours, the aggregated protein dissociates and adopts a conformation comparable to that of native protein adsorbed to the interface. The exerted surface pressure is higher for aggregated material, most probably because the deformability of the particle is smaller. Aggregated protein has a lower ability to desorb from the interface upon compression of the surface layer, resulting in a steadily increasing surface pressure upon reducing the available area for the surface layer. This observation is opposite to what is observed for succinylated protein that may desorb more easily and thereby suppresses the buildup of a surface pressure. Generally, this work demonstrates that modulating the ability of proteins to self-associate offers a tool to control the rheological properties of interfaces.
Topics
Food technologyAggregationAir-water interfaceFCSIRRASOvalbuminMonomerOvalbuminSuccinic acid derivativeWaterAdsorptionAir water interfaceCovalent bondDesorptionDiffusionDissociationEggElectricityFlow kineticsFluorescence correlation spectroscopyHeat treatmentInfrared reflection absorption spectroscopyPriority journalProtein aggregationProtein assemblyProtein conformationProtein modificationSpectroscopySurface propertySurface tensionAdsorptionAirAnimalsBoron CompoundsChickensElectrostaticsHeatKineticsMicroscopy, FluorescenceOvalbuminOvumPressureProtein ConformationProtein Structure, SecondaryProteomicsRheologySpectrometry, FluorescenceSpectroscopy, Fourier Transform InfraredSurface PropertiesTime FactorsWaterGallus gallus
TNO Identifier
238326
ISSN
09618368
Source
Protein Science, 14(2), pp. 483-493.
Pages
483-493
Files
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