title: Selective isolation of G-quadruplexes by affinity chromatography.
abstract: G-quadruplex (G4) is a characteristic secondary structure of nucleic acids containing repetitive tandem guanines. G4-forming sequences are found prevalent in the human genome by bioinformatics analysis. Accumulating evidence has suggested that G4s are involved in many biological processes. Selective isolation of G4s would be an effective tool in the study of G4s. In this paper, we prepared four affinity matrixes using hemin or a perylene derivative (N,N'-Bis-(2-(amino)ethyl)-3,4,9,10-perylenetetracarboxylic acid diimide, Pery01) as ligand, and investigated the retention behaviors of different G4s on these matrixes. Our experimental results suggest that the π-π stacking interaction between ligand and G-tetrad plays a key role in the selective isolation of G4s, whereas the electrostatic interaction between DNA and matrix causes the nonspecific binding. One matrix prepared by immobilizing Pery01 on polyglycidylmethacrylate (PGMA) beads through an aminocaproic acid spacer exhibits good selectivity for parallel structure G4s and has been successfully used to directly isolate a spiked parallel G4 from plasma.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Tianjun
authors.initials: T
authors.lastname: Chang
authors.forename: Xiangjun
authors.initials: X
authors.lastname: Liu
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Cheng
authors.forename: Cui
authors.initials: C
authors.lastname: Qi
authors.forename: Hongcheng
authors.initials: H
authors.lastname: Mei
authors.forename: Dihua
authors.initials: D
authors.lastname: Shangguan
mesh_terms: D002846:Chromatography, Affinity / Q000379:methods*; D004247:DNA / Q000097:blood / Q000235:genetics / Q000302:isolation & purification*; D054856:G-Quadruplexes; D006427:Hemin / Q000737:chemistry; D006801:Humans; D007094:Imides / Q000737:chemistry; D009841:Oligonucleotides / Q000235:genetics / Q000302:isolation & purification; D010569:Perylene / Q000031:analogs & derivatives / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D013050:Spectrometry, Fluorescence
chemical_list: D007094:Imides; D009841:Oligonucleotides; D011109:Polymethacrylic Acids; C517085:perylenetetracarboxylic diimide; C042535:polyglycidyl methacrylate; D010569:Perylene; D006427:Hemin; D004247:DNA