Characterization of the Binding of the Finland Trityl Radical with Bovine Serum Albumin.
Characterization of the Binding of the Finland Trityl Radical with Bovine Serum Albumin.
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芬兰三苯甲基自由基与牛血清白蛋白结合的特征。
DOI：
10.1039/c4ra04616a
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发表时间：
2014-01-01
期刊：
影响因子：
3.9
通讯作者：
Zweier JL
中科院分区：
文献类型：
--
作者：
Song Y;Liu Y;Liu W;Villamena FA;Zweier JL
了解三烷基自由基与蛋白质的相互作用是扩大其生物医学应用的必要条件。在这项工作中，我们证明芬兰三甲基自由基CT-03在水溶液中与牛血清白蛋白（BSA）结合。在与BSA结合后，CT-03表现出更宽的电子顺磁共振（EPR）信号，这种谱线展宽可以通过BSA的蛋白水解而逆转。这种结合导致CT-03的最大UV-Vis吸收波长在470 nm左右发生红移，这可能是由于CT-03位于蛋白质的相对疏水区域。CT-03与BSA之间的相互作用是由疏水相互作用驱动的，估计在298 K时的结合常数为2.18 ×105 M−1。此外，每个BSA分子仅结合一个CT-03，并且确定其结合位点为子结构域IIA （Sudlow 's site I）。三烷基探针与白蛋白的蛋白质结合可用于研究白蛋白的结构和功能，也必须考虑将其用作体内显像剂或自旋标记。
Understanding the interactions of trityl radicals with proteins is required to expand their biomedical applications. In this work, we demonstrate that the Finland trityl radical CT-03 binds to bovine serum albumin (BSA) in aqueous solution. Upon binding with BSA, CT-03 exhibits a much broader electron paramagnetic resonance (EPR) signal and this line broadening can be reversed by proteolysis of the BSA. The binding induces a red-shift of the maximal UV-Vis absorbance wavelength of CT-03 around 470 nm, likely due to localization of CT-03 in the relatively hydrophobic region of the protein. The interaction between CT-03 and BSA is driven by a hydrophobic interaction with an estimated binding constant of 2.18 ×105 M−1 at 298 K. Furthermore, only one CT-03 is bound to each molecule of BSA and the binding site is determined to be the sub-domain IIA (Sudlow’s site I). This protein binding of the trityl probe to albumin can be used to study the structure and function of albumin and also must be considered for its use as an in vivo imaging agent or spin label.