Rowland Institute at Harvard University, 100 Edwin Land Boulevard, Cambridge, MA 02142, USA.
College of Engineering, Swansea University, Swansea SA1 8EN, UK.
Sci Adv. 2017 May 26;3(5):e1602991. doi: 10.1126/sciadv.1602991. eCollection 2017 May.
Current methods to study molecular interactions require labeling the subject molecules with fluorescent reporters. However, the effect of the fluorescent reporters on molecular dynamics has not been quantified because of a lack of alternative methods. We develop a hybrid photonic-plasmonic antenna-in-a-nanocavity single-molecule biosensor to study DNA-protein dynamics without using fluorescent labels. Our results indicate that the fluorescein and fluorescent protein labels decrease the interaction between a single DNA and a protein due to weakened electrostatic interaction. Although the study is performed on the DNA-XPA system, the conclusion has a general implication that the traditional fluorescent labeling methods might be misestimating the molecular interactions.
目前研究分子相互作用的方法需要用荧光报告基团标记研究对象分子。但是由于缺乏替代方法，荧光报告基团对分子动力学的影响尚未被量化。我们开发了一种混合光子等离子体天线-纳米腔单分子生物传感器，用于在不使用荧光标记的情况下研究 DNA-蛋白质动力学。我们的研究结果表明，由于静电相互作用减弱，荧光素和荧光蛋白标签降低了单个 DNA 和蛋白质之间的相互作用。尽管这项研究是在 DNA-XPA 系统上进行的，但该结论具有普遍意义，即传统的荧光标记方法可能会错误估计分子相互作用。
