School of Food Science and Engineering, Harbin Institute of Technology, 73 Huanghe Road, Harbin, Heilongjiang 150090, PR China.
Food Chem. 2013 Nov 15;141(2):1504-11. doi: 10.1016/j.foodchem.2013.02.099. Epub 2013 Mar 7.
The binding of curcumin (CCM) to bovine β-lactoglobulin (β-Lg) was investigated by Fourier transform infrared and fluorescence. The effect of binding on antioxidant activity of CCM was determined by using ABTS and hydroxyl radical scavenging capacity and total reducing ability. Our results showed that when CCM binds to β-Lg, it lead to a partial change in protein structure. In fact, CCM was bound respectively to two different sites of protein at pH 6.0 and 7.0 via hydrophobic interaction. CCM-β-Lg complex was formed by one molecule of protein combining with one molecule of CCM. Moreover, the average distance from one binding site to Trp residues in protein is similar with another. This result suggested that fluorescence resonance energy transfer cannot be used as unique method to study the characteristics of binding of ligands to proteins. The antioxidant activity of CCM might be improved by binding with β-Lg.
通过傅里叶变换红外和荧光研究了姜黄素（CCM）与牛β-乳球蛋白（β-Lg）的结合。通过 ABTS 和羟基自由基清除能力和总还原能力测定了结合对 CCM 抗氧化活性的影响。我们的结果表明，当 CCM 与 β-Lg 结合时，会导致蛋白质结构的部分变化。事实上，CCM 通过疏水相互作用分别在 pH 值为 6.0 和 7.0 时结合到蛋白质的两个不同位点上。CCM-β-Lg 复合物由一个蛋白质分子与一个 CCM 分子结合形成。此外，一个结合位点到蛋白质中色氨酸残基的平均距离与另一个相似。这一结果表明，荧光共振能量转移不能作为唯一的方法来研究配体与蛋白质结合的特性。CCM 的抗氧化活性可能通过与 β-Lg 结合而提高。
