Mandal Shankar, Hoque Mohammed Enamul, Mao Hanbin
Department of Chemistry and Biochemistry, Kent State University, Kent, OH, USA.
Methods Mol Biol. 2019;2035:275-298. doi: 10.1007/978-1-4939-9666-7_16.
The genome-wide occurrence of G-quadruplexes and their demonstrated biological activities call for detailed understanding on the stability and transition kinetics of the structures. Although the core structural element in a G-quadruplex is simple and requires only four tandem repeats of Guanine rich sequences, there is rather rich conformational diversity in this structure. Corresponding to this structural diversity, it displays involved transition kinetics within individual G-quadruplexes and complicated interconversion among different G-quadruplex species. Due to the inherently high signal-to-noise ratio in the measurement, single-molecule tools offer a unique capability to investigate the thermodynamic, kinetic, and mechanical properties of G-quadruplexes with dynamic conformations. In this chapter, we describe different single molecule methods such as atomic-force microscopy (AFM), single-molecule fluorescence resonance energy transfer (smFRET), optical, magnetic, and magneto-optical tweezers to investigate G-quadruplex structures as well as their interactions with small-molecule ligands.
全基因组范围内G-四链体的存在及其已证实的生物学活性，需要我们对其结构的稳定性和转变动力学有详细的了解。尽管G-四链体中的核心结构元件很简单，只需要四个富含鸟嘌呤的序列串联重复，但该结构具有相当丰富的构象多样性。与此结构多样性相对应的是，它在单个G-四链体内表现出复杂的转变动力学，以及不同G-四链体物种之间复杂的相互转化。由于测量中固有的高信噪比，单分子工具提供了一种独特的能力，能够研究具有动态构象的G-四链体的热力学、动力学和力学性质。在本章中，我们描述了不同的单分子方法，如原子力显微镜（AFM）、单分子荧光共振能量转移（smFRET）、光学镊子、磁性镊子和磁光镊子，以研究G-四链体结构及其与小分子配体的相互作用。
