Abstract:
The binding constant is an important characteristic of a DNA-binding protein. A large number of methods exist to measure the binding constant, but many of those methods have intrinsic flaws that influence the outcome of the characterization. Tethered particle motion (TPM) is a simple, cheap, and high-throughput single-molecule method that can be used to measure binding constants of proteins binding to DNA reliably, provided that they distort DNA. In TPM, the motion of a bead tethered to a surface by DNA is tracked using light microscopy. A protein binding to the DNA will alter bead motion. This change in bead motion makes it possible to measure the DNA-binding properties of proteins. We use the bacterial protein integration host factor (IHF) and the archaeal histone HMfA as examples to show how specific binding to DNA can be measured. Moreover, we show how the end-to-end distance can provide structural insights into protein-DNA binding.
摘要:
结合常数是DNA结合蛋白的重要特征。存在大量的方法来测量结合常数,但是这些方法中的许多都存在影响表征结果的内在缺陷。系留粒子运动(TPM)是一种简单的,便宜,和高通量单分子方法,可用于可靠地测量蛋白质与DNA结合的结合常数,前提是它们会扭曲DNA.在TPM中,使用光学显微镜跟踪由DNA束缚到表面的珠子的运动。与DNA结合的蛋白质将改变珠子运动。珠子运动的这种变化使得可以测量蛋白质的DNA结合特性。我们使用细菌蛋白质整合宿主因子(IHF)和古细菌组蛋白HMfA作为示例,以显示如何测量与DNA的特异性结合。此外,我们展示了端到端距离如何提供蛋白质-DNA结合的结构见解。