Engineering a signal transduction mechanism for protein-based biosensors
Engineering a signal transduction mechanism for protein-based biosensors
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DOI：
10.1073/pnas.0503055102
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发表时间：
2005-08-02
影响因子：
11.1
通讯作者：
Plaxco, KW
中科院分区：
文献类型：
--
作者：
Kohn, JE;Plaxco, KW
杂交诱导的构象变化已成功用于生物传感器，将 DNA 结合事件转导为易于观察的光学或电子信号。然而，类似的信号转导尚未被证明在基于蛋白质的生物传感器中具有同等的效用。出现这种差异的原因是，与 ssDNA 不同，大多数蛋白质在配体结合时不会发生显着的构象变化。在这里，我们描述了这个问题的解决方案。我们证明，可以合理地设计任意选择的、通常折叠良好的蛋白质，使其经历配体诱导的折叠。这种工程蛋白能够快速（毫秒）选择性地响应其目标，并将识别与最大可能的构象变化：折叠结合起来。这些特征表明配体诱导的折叠可以作为理想的信号转导机制。 Consistent with this claim, we demonstrate a label-free optical biosensor based on the effect that is sufficiently selective to detect its target even in complex, contaminant-ridden samples such as blood serum.
Hybridization-induced conformational changes have been successfully used in biosensors for the transduction of DNA-binding events into readily observable optical or electronic signals. Similar signal transduction has not, however, proven of equal utility in protein-based biosensors. The discrepancy arises because, unlike ssDNA, most proteins do not undergo significant conformational changes upon ligand binding. Here, we describe a solution to this problem. We show that an arbitrarily selected, normally well folded protein can be rationally engineered such that it undergoes ligand-induced folding. The engineered protein responds rapidly (milliseconds) and selectively to its target, and it couples recognition with the largest possible conformational change: folding. These traits suggest that ligand-induced folding could serve as an ideal signal-transduction mechanism. Consistent with this claim, we demonstrate a label-free optical biosensor based on the effect that is sufficiently selective to detect its target even in complex, contaminant-ridden samples such as blood serum.