Changes in beta-Lactoglobulin conformation at the oil/water interface of emulsions studied by synchrotron radiation circular dichroism spectroscopy
Zhai, J. and Miles, Andrew J. and Pattenden, L.K. and Lee, T.H. and Augustin, M.A. and Wallace, Bonnie A. and Aguilar, M.I. and Wooster, T.J. (2010) Changes in beta-Lactoglobulin conformation at the oil/water interface of emulsions studied by synchrotron radiation circular dichroism spectroscopy. Biomacromolecules 11 (8), pp. 2136-2142. ISSN 1525-7797.
The structure of proteins at interfaces is a key factor determining the stability as well as organoleptic properties of food emulsions. While it is widely believed that proteins undergo conformational changes at interfaces, the measurement of these structural changes remains a significant challenge. In this study, the conformational changes of beta-lactoglobulin (beta-Lg) upon adsorption to the interface of hexadecane oil-in-water emulsions were investigated using synchrotron radiation circular dichroism (SRCD) spectroscopy. Far-UV SRCD spectra showed that adsorption of beta-Lg to the O/W interface caused a significant increase in non-native a-helix structure, accompanied by a concomitant loss of beta-sheet structure. Near-UV SRCD spectra revealed that a considerable disruption of beta-Lg tertiary structure occurred upon adsorption. Moreover, heat-induced changes to the non-native beta-Lg conformation at the oil/water interface were very small compared to the dramatic loss of beta-Lg secondary structure that occurred during heating in solution, suggesting that the interface has a stabilizing effect on the structure of non-native beta-Lg. Overall, our findings provide insight into the conformational behavior of proteins at oil/water interfaces and demonstrate the applicability of SRCD spectroscopy for measuring the conformation of adsorbed proteins in optically turbid emulsions.
|Keyword(s) / Subject(s):||Protein secondary structure, sodium dodeycl-sulfate, oil-water interfaces, milk-proteins, binding site, adsorption, functionality, flocculation, aggregation, equilibrium|
|School:||Birkbeck Schools and Departments > School of Science > Biological Sciences|
|Research Centre:||Structural Molecular Biology, Institute of (ISMB)|
|Date Deposited:||24 May 2011 13:26|
|Last Modified:||06 Dec 2016 10:40|
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