卵白蛋白与油酸相互作用的光谱学分析

Spectroscopic Analysis of the Interaction between Ovalbumin and Oleic Acid

运用荧光光谱、同步荧光光谱、傅里叶变换红外光谱和圆二色谱研究卵白蛋白与油酸相互作用的方式及机理。结果表明,油酸与卵白蛋白相互作用导致卵白蛋白荧光猝灭,猝灭方式由动态猝灭(未加热处理)转变为静态猝灭(加热处理),其相互作用力为疏水作用和氢键,且随着油酸浓度的增大,相互作用力增强。与油酸相互作用后,卵白蛋白酪氨酸残基和色氨酸残基的荧光光谱蓝移,α-螺旋和β-转角的含量减少,β-折叠含量增加;而无规卷曲的含量增大(油酸与卵白蛋白物质的量比为10∶1)。综上所述,油酸与卵白蛋白间通过疏水作用和氢键发生相互作用,导致卵白蛋白二级结构发生变化。

The characteristics of the interaction between ovalbumin（OVA） and oleic acid（OA） were investigated by using fluorescence spectroscopy, synchronous fluorescence spectroscopy, Fourier transform infrared spectroscopy and circular dichroism spectrum. The results revealed that the interaction between OA and OVA quenched the fluorescence of OVA, and the quenching mode changed from dynamic mode（without heating） to static mode（with heating）. Hydrophobic interaction and hydrogen bond played a dominant role in this interaction, and these forces were stronger with increasing OA concentration. After interaction with OA, the fluorescence peaks of tyrosine and tryptophan residues in OVA were blue shifted; α-helix and β-turn contents were decreased significantly, β-sheet content was increased significantly, while random coil content was increased only at high OA concentration. In conclusion, OVA conformation was altered upon OA interaction driven by hydrophobic interaction and hydrogen bond.