title: G-quadruplex induced stabilization by 2'-deoxy-2'-fluoro-D-arabinonucleic acids (2'F-ANA).
abstract: The impact of 2'-deoxy-2'-fluoroarabinonucleotide residues (2'F-araN) on different G-quadruplexes derived from a thrombin-binding DNA aptamer d(G2T2G2TGTG2T2G2), an anti-HIV phosphorothioate aptamer PS-d(T2G4T2) and a DNA telomeric sequence d(G4T4G4) via UV thermal melting (T(m)) and circular dichroism (CD) experiments has been investigated. Generally, replacement of deoxyguanosines that adopt the anti conformation (anti-guanines) with 2'F-araG can stabilize G-quartets and maintain the quadruplex conformation, while replacement of syn-guanines with 2'F-araG is not favored and results in a dramatic switch to an alternative quadruplex conformation. It was found that incorporation of 2'F-araG or T residues into a thrombin-binding DNA G-quadruplex stabilizes the complex (DeltaT(m) up to approximately +3 degrees C/2'F-araN modification); 2'F-araN units also increased the half-life in 10% fetal bovine serum (FBS) up to 48-fold. Two modified thrombin-binding aptamers (PG13 and PG14) show an approximately 4-fold increase in binding affinity to thrombin, as assessed via a nitrocellulose filter binding assay, both with increased thermal stability (approximately 1 degrees C/2'F-ANA modification increase in T(m)) and nuclease resistance (4-7-fold) as well. Therefore, the 2'-deoxy-2'-fluoro-d-arabinonucleic acid (2'F-ANA) modification is well suited to tune (and improve) the physicochemical and biological properties of naturally occurring DNA G-quartets.
authors.affiliation: Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, QC, Canada H3A 2K6.
authors.forename: Chang Geng
authors.initials: CG
authors.lastname: Peng
authors.forename: Masad J
authors.initials: MJ
authors.lastname: Damha
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry* / Q000378:metabolism; D001088:Arabinonucleotides / Q000737:chemistry*; D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry*; D003851:Deoxyribonucleases / Q000378:metabolism; D054856:G-Quadruplexes; D006147:Guanine / Q000737:chemistry; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D016615:Telomere / Q000737:chemistry
chemical_list: C507672:2'-deoxy-2'-fluoro-beta-D-arabinonucleic acid; D052157:Aptamers, Nucleotide; D001088:Arabinonucleotides; C081676:thrombin aptamer; D006147:Guanine; D004247:DNA; D003851:Deoxyribonucleases