Combining chemoselective ligation with polyhistidine-driven self-assembly for the modular display of biomolecules on quantum dots.
Combining chemoselective ligation with polyhistidine-driven self-assembly for the modular display of biomolecules on quantum dots.
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DOI：
10.1021/nn901393v
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发表时间：
2010-01-26
期刊：
影响因子：
17.1
通讯作者：
Medintz IL
中科院分区：
文献类型：
--
作者：
Prasuhn DE;Blanco-Canosa JB;Vora GJ;Delehanty JB;Susumu K;Mei BC;Dawson PE;Medintz IL
在生物学中更广泛地结合半导体量子点（QD）的主要障碍之一是缺乏容易的连接化学来产生不同类型的功能性QD-生物缀合物。一个两步模块化的策略介绍的生物分子的CdSe/ZnS核/壳量子点在这里描述的是利用化学选择性，苯胺催化的腙偶联化学附加到肽和DNA的六聚组氨酸序列。这特别地为它们提供了比率自组装成亲水性QD的能力。通过连接蛋白水解底物肽、寡精氨酸细胞穿透肽或DNA探针与同源六组氨酸肽基序列来突出这种标记方法的多功能性。模块化允许随后自组装的QD构建体参与不同类型的靶向生物测定。通过凝胶电泳和Förster共振能量转移分析首次证实了单个QD缀合物的自组装和光物理性质。量子点-染料标记的肽共轭物，然后用作生物传感器，定量监测半胱天冬酶-3或弹性蛋白酶的蛋白水解活性，从不同的物种。这些传感器允许确定相应的动力学参数，包括米氏常数（KM）和最大蛋白水解活性（Vmax）。显示用细胞穿透肽修饰的QD被HEK 293 T/17细胞成功内化，而展示肽-DNA缀合物的纳米晶体在杂交微阵列测定中用作荧光探针。这种用于在QD上展示肽或DNA的模块化方法可以扩展到其他更复杂的生物分子，例如蛋白质或与不同类型的纳米颗粒材料一起使用。
One of the principle hurdles to wider incorporation of semiconductor quantum dots (QDs) in biology is the lack of facile linkage chemistries to create different types of functional QD-bioconjugates. A two-step modular strategy for the presentation of biomolecules on CdSe/ZnS core/shell QDs is described here which utilizes a chemoselective, aniline-catalyzed hydrazone coupling chemistry to append hexahistidine sequences onto peptides and DNA. This specifically provides them the ability to ratiometrically self-assemble to hydrophilic QDs. The versatility of this labeling approach was highlighted by ligating proteolytic substrate peptides, an oligoarginine cell-penetrating peptide, or a DNA-probe to cognate hexahistidine peptidyl sequences. The modularity allowed subsequently self-assembled QD constructs to engage in different types of targeted bioassays. The self-assembly and photophysical properties of individual QD conjugates were first confirmed by gel electrophoresis and Förster resonance energy transfer analysis. QD-dye-labeled peptide conjugates were then used as biosensors to quantitatively monitor the proteolytic activity of caspase-3 or elastase enzymes from different species. These sensors allowed the determination of the corresponding kinetic parameters, including the Michaelis constant (KM) and the maximum proteolytic activity (Vmax). QDs decorated with cell-penetrating peptides were shown to be successfully internalized by HEK 293T/17 cells, while nanocrystals displaying peptide-DNA conjugates were utilized as fluorescent probes in hybridization microarray assays. This modular approach for displaying peptides or DNA on QDs may be extended to other more complex biomolecules such as proteins or utilized with different types of nanoparticle materials.