Insight into the effect of charge regulation on the binding mechanism of curcumin to myofibrillar protein.
Insight into the effect of charge regulation on the binding mechanism of curcumin to myofibrillar protein.
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DOI：
10.1016/j.foodchem.2021.129395
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发表时间：
2021-02
期刊：
影响因子：
8.8
通讯作者：
Changling Wu;Hualin Dong;Peng Wang;Xinglian Xu;Yue Zhang;Yian Li
中科院分区：
文献类型：
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作者：
Changling Wu;Hualin Dong;Peng Wang;Xinglian Xu;Yue Zhang;Yian Li
肌原纤维蛋白（MPs）作为一种食品级材料，具有提高姜黄素溶解度和生物利用度的潜力。然而，在碱性pH和NaCl诱导的电荷调节下，MPs与姜黄素的相互作用机制尚不清楚。本研究通过不同NaCl浓度（0、0.3、0.6和0.9 mol/L）下的荧光猝灭，证实了姜黄素与MPs在pH为12时的结合。进一步的动力学实验表明，在NaCl存在下，MPs对姜黄素具有较高的亲和力，特别是在0.6 M NaCl下。随着pH值从12到7的变化，蛋白质-姜黄素分散体的紫外-可见吸收光谱不受影响。MPs的二级结构不受与姜黄素结合的影响。这种稳定络合物的形成可以用疏水性而不是静电相互作用来解释。因此，由于疏水相互作用的重要性，NaCl的存在促进了疏水口袋的暴露，从而提高了姜黄素与MPs之间的结合亲和力。
Myofibrillar proteins (MPs), as a food-grade material, have the potential to improve the solubility and bioavailability of curcumin. However, the interaction mechanism between MPs and curcumin under charge regulation induced by alkaline pH and NaCl was unclear. In this study, the binding between curcumin and MPs at pH 12 was confirmed by the fluorescence quenching under different NaCl concentration (0, 0.3, 0.6 and 0.9 mol/L). Further kinetic experiments showed, MPs possessed a higher affinity to bind curcumin in the presence of NaCl, especially at 0.6 M NaCl. Followed pH shifting from 12 to 7 does not affect UV–Vis absorption spectra of protein-curcumin dispersions. The secondary structure of MPs was not affected by binding with curcumin. Formation of this stable complex can be explained by hydrophobic other than electrostatic interaction. Therefore, the presence of NaCl facilitated exposure of hydrophobic pocket to improve the binding affinity between curcumin and MPs due to the importance of hydrophobic interaction.