Interaction of beta-Lactoglobulin with Resveratrol and its Biological Implications

摘要

beta-Lactoglobulin(beta-LG),the major whey protein in the milk of ruminants,has a high affinity for a wide range of compounds.Resveratrol(3,5,4'-trihydroxystilbene),a natural polyphenolic compound found in grapes and red wine,exhibits many physiological effects associated with health benefits.In this study,the interaction of resveratrol with beta-LG was investigated using circular dichroism,fluorescence and UV-vis absorbance.Self-association of resveratrol possibly occurs at high concentrations.Resveratrol interacts with beta-LG to form 1:1 complexes.Resveratrol is bound to the surface of the protein because beta-LG-bound polyphenol is in a weaker hydrophobic environment relative to 75% ethanol.The binding constant for the resveratrol-beta-LG interaction is between 104 and 10~6 M`(-1),as determined by protein or polyphenol fluorescence.The beta-LG-resveratrol interaction may compete with self-association of both the polyphenol and the protein.It has no apparent influence on beta-LG secondary structure but partially disrupts tertiary structure.Complexing with beta-LG provides a slight increase in the photostability of resveratrol and a significant increase in its hydrosolubility.