Kinetics of metal-affinity driven self-assembly between proteins or peptides and CdSe-ZnS quantum dots
Kinetics of metal-affinity driven self-assembly between proteins or peptides and CdSe-ZnS quantum dots
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DOI：
10.1021/jp073550t
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发表时间：
2007-08-09
影响因子：
3.7
通讯作者：
Mattoussi, Hedi
中科院分区：
文献类型：
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作者：
Sapsford, Kim E.;Pons, Thomas;Mattoussi, Hedi
我们提出了一种金属亲和力驱动的金属亲和力驱动的量子点(QD)与一系列带有不同长度多组氨酸标签的蛋白质和多肽之间的自组装的分子表征。特别是，我们研究了流动条件下表面固定化量子点与蛋白质/多肽之间以及自由扩散的量子点与蛋白质/多肽(溶液相)之间的自组装动力学。在第一种构型中，量子点被固定在功能化的底物上，然后暴露在染料标记的多肽/蛋白质中。利用逝去波激发，我们通过监测染料荧光随时间的变化来评估自组装。在溶液中，通过量子点与染料标记的蛋白质/多肽之间的能量转移来监测自组装的动力学。这些测量可以确定动力学参数，包括缔合和解离速率(k(开)和k(关))和表观结合常数(K-d)。我们发现自组装是快速的，溶液自组装的平衡常数K-d(-1)接近1 nm，证实了金属-亲和力相互作用提供了功能和稳定的量子点生物偶联物。
We present a molecular characterization of metal-affinity driven self-assembly between CdSe-ZnS core-shell quantum dots (QDs) and a series of proteins and peptides appended with various length polyhistidine tags. In particular, we investigated the kinetics of self-assembly between surface-immobilized QDs and proteins/peptides under flow conditions, as well as between freely diffusing QDs and proteins/peptides (solution phase). In the first configuration, QDs were immobilized onto functionalized substrates and then exposed to dye-labeled peptides/proteins. Using evanescent wave excitation, we assessed self-assembly by monitoring the time-dependent changes in the dye fluorescence. In solution, the kinetics of self-assembly was monitored via energy transfer between QDs and dye-labeled proteins/peptides. These measurements allowed determination of the kinetic parameters, including the association and dissociation rates (k(on) and k(off)) and the apparent binding constant (K-d). We find that self-assembly is rapid with an equilibrium constant K-d(-1) approximate to 1 nM for solution self-assembly, confirming that metal-affinity interactions provide QD bioconjugates that are functional and stable.