The effect of Cu2+ on interaction between flavonoids with different C-ring substituents and bovine serum albumin: Structure-affinity relationship aspect
The effect of Cu2+ on interaction between flavonoids with different C-ring substituents and bovine serum albumin: Structure-affinity relationship aspect
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Cu2+对不同C环取代基黄酮类化合物与牛血清白蛋白相互作用的影响：结构-亲和关系方面
DOI：
10.1016/j.jinorgbio.2011.08.007
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发表时间：
2011-12-01
影响因子：
3.9
通讯作者：
Peng, Mijun
中科院分区：
文献类型：
--
作者：
Zhang, Yuping;Shi, Shuyun;Peng, Mijun
用荧光等多种光谱方法研究了四种A环和Brings环相同但C环取代基不同的黄酮类化合物槲皮素（QU）、毛地黄黄酮（LU）、花旗松素（TA）和（+）-儿茶素（CA）与牛血清白蛋白（BSA）在Cu ~（2+）存在和不存在下的结合。紫外-可见和圆二色性（CD）。结果表明，黄酮类化合物3位羟基的引入提高了黄酮类化合物与BSA的结合亲和力。结合亲和力大小顺序为：QU>CA>TA>LU。Cu ~（2+）的存在显著影响黄酮类化合物与BSA的相互作用。QU和TA与BSA的结合亲和力分别降低了6.7%和13.2%。而LU和CA与BSA的结合亲和力分别提高了43.0%和20.7%。Cu ~（2+）-类黄酮络合物的形成和空间位阻共同影响了QU、LU和TA与BSA的结合亲和力，而BSA的构象变化可能是CA与BSA结合亲和力增加的主要原因。然而，QU，LU，TA和CA对BSA的猝灭机制是基于静态猝灭结合非辐射能量转移，而不管是否存在Cu 2+。紫外-可见光谱结果表明，BSA的构象发生了变化，并形成了类黄酮-Cu ~（2+）络合物。圆二色谱结果也解释了BSA与黄酮类化合物结合时构象的变化。(C)2011 Elsevier Inc. All rights reserved.
Four flavonoids quercetin (QU), luteolin (LU), taxifolin (TA) and (+)-catechin (CA) with the same A- and Brings but different C-ring substituents have been investigated for their binding to bovine serum albumin (BSA) in the absence and presence of Cu2+ by means of various spectroscopic methods such as fluorescence. UV-visible and circular dichroism (CD). The results indicated that hydroxyl group at 3-position increased the binding affinities between flavonoids and BSA. The values of the binding affinities were in the order: QU>CA>TA>LU. The presence of Cu2+ affected the interactions of flavonoids with BSA significantly. The binding affinities of QU and TA for BSA were decreased about 6.7% and 13.2%. However, the binding affinities of LU and CA for BSA were increased about 43.0% and 20.7%. The formation of Cu2+-flavonoid complex and steric hindrance together influenced the binding affinities of QU, LU and TA for BSA, while the conformational change of BSA may be the main reason for the increased binding affinity of CA for BSA. However, the quenching mechanism for QU, LU, TA and CA to BSA was based on static quenching combined with non-radiative energy transfer irrespective of the absence or presence of Cu2+. The UV-visible results showed the change in BSA conformation and the formation of flavonoid-Cu2+ complex. The CD results also explained the conformational changes of BSA on binding with flavonoids. (C) 2011 Elsevier Inc. All rights reserved.