Binding of curcumin with bovine serum albumin in the presence of ι-carrageenan and implications on the stability and antioxidant activity of curcumin.
Binding of curcumin with bovine serum albumin in the presence of ι-carrageenan and implications on the stability and antioxidant activity of curcumin.
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DOI：
10.1021/jf401827x
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发表时间：
2013-07
影响因子：
6.1
通讯作者：
M. Yang;Yue Wu;Jinbing Li;Haibo Zhou;Xiaoyong Wang
中科院分区：
文献类型：
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作者：
M. Yang;Yue Wu;Jinbing Li;Haibo Zhou;Xiaoyong Wang
本工作研究了牛血清白蛋白/ι-卡拉胶复合体的形成对姜黄素的结合、稳定性和抗氧化活性的影响。在牛血清白蛋白和ι-卡拉胶存在下，姜黄素比游离的姜黄素和只与牛血清白蛋白结合的姜黄素具有更强的吸收和荧光强度。观察到添加ι-卡拉胶能促进姜黄素猝灭牛血清白蛋白的本征荧光。这些结果可以用牛血清白蛋白/ι-卡拉胶复合体的形成来解释，它有助于稳定牛血清白蛋白的折叠结构，为姜黄素提供一个更疏水的微环境。姜黄素与牛血清白蛋白和牛血清白蛋白/ι-卡拉胶复合体各向异性值的微小差异表明，ι-卡拉胶在牛血清白蛋白/ι-卡拉胶复合体中以外伸缩构象形式存在，但不直接干扰牛血清白蛋白内部的疏水空穴，而姜黄素是疏水的。姜黄素与牛血清白蛋白/ι-卡拉胶络合物结合常数的测定值高于单独与牛血清白蛋白的结合常数。此外，BSA/ι-卡拉胶复合体在增强姜黄素的稳定性和清除DPPH自由基方面优于单一的BSA。
This work studied the influences of formation of BSA/ι-carrageenan complexes on the binding, stability, and antioxidant activity of curcumin. In the presence of BSA and ι-carrageenan, curcumin gives higher intensities of absorption and fluorescence than free curcumin and curcumin only combined with BSA. The added ι-carrageenan is observed to promote curcumin for quenching the instrinsic fluorescence of BSA. These results are explained in terms of the formation of BSA/ι-carrageenan complexes, which help to stabilize the folded structure of BSA for providing curcumin with a more hydrophobic microenvironment. The small difference in anisotropy values of curcumin with BSA alone and of BSA/ι-carrageenan complexes suggests that ι-carrageenan acts as outer stretch conformation in BSA/ι-carrageenan complexes but does not directly disturb the hydrophobic pockets inside BSA, where curcumin is hydrophobically located. The determined values of the binding constant are higher for curcumin with BSA/ι-carrageenan complexes than with BSA alone. Moreover, BSA/ι-carrageenan complexes are found to be superior to single BSA for enhancing the stability and DPPH radical-scavenging ability of curcumin.