Smith Jasmine S, Johnson F Brad
Department of Pathology, Cancer Biology Program, and Institute on Aging, University of Pennsylvania School of Medicine, Philadelphia, PA, USA.
Methods Mol Biol. 2010;608:207-21. doi: 10.1007/978-1-59745-363-9_13.
DNA can adopt a variety of non-standard conformations, including structures known as G-quadruplexes (G4-DNA), which consist of stacked tetrads of guanines. There are growing indications that G4-DNA is of biological importance, including evidence that it plays roles in telomere function, DNA recombination and the regulation of transcription and translation. However, it has been difficult to obtain direct, physical evidence for the presence of G-quadruplex DNA in vivo due, in part, to a lack of tools for G4-DNA identification. Here, we describe a method for coupling the G4-DNA binding ligand N-methyl mesoporphyrin IX (NMM) to a Sepharose resin, and demonstrate the ability of the resin to bind tightly and selectively to DNA oligonucleotides with the capacity to form G4-DNA. This technique might also be extended to examine genomic distributions of G4-DNA isolated from in vivo sources.
DNA能够呈现多种非标准构象，包括被称为G-四链体（G4-DNA）的结构，其由鸟嘌呤的堆叠四联体组成。越来越多的迹象表明G4-DNA具有生物学重要性，包括它在端粒功能、DNA重组以及转录和翻译调控中发挥作用的证据。然而，由于缺乏用于G4-DNA鉴定的工具，很难获得体内存在G-四链体DNA的直接物理证据。在此，我们描述了一种将G4-DNA结合配体N-甲基中卟啉IX（NMM）偶联到琼脂糖树脂上的方法，并证明了该树脂能够紧密且选择性地结合具有形成G4-DNA能力的DNA寡核苷酸。该技术也可能扩展到检查从体内来源分离的G4-DNA的基因组分布。
