Atomic Force Microscopy and Voltammetric Investigation of Quadruplex Formation between a Triazole-Acridine Conjugate and Guanine-Containing Repeat DNA Sequences

The interactions of the Tetrahymena telomeric repeat sequence d(TG4T) and the polyguanylic acid (poly(G)) sequence with the quadruplex-targeting triazole-linked acridine ligand GL15 were investigated using atomic force microscopy (AFM) at a highly oriented pyrolytic graphite and voltammetry at a gla...

Descripción completa

Detalles Bibliográficos
Autores: Chiorcea-Paquim, Ana-Maria, Rodrigues Pontinha, Ana Dora, Eritja Casadellà, Ramón, Lucarelli, Genny, Sparapani, Silvia, Neidle, Stephen, Oliveira-Brett, Ana Maria
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2015
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/129818
Acceso en línea:http://hdl.handle.net/10261/129818
Access Level:acceso abierto
Palabra clave:Quadruplex formation
Carbon
Electrodes
Voltammetric investigation
DNA
chemical structure
Triazoles
Descripción
Sumario:The interactions of the Tetrahymena telomeric repeat sequence d(TG4T) and the polyguanylic acid (poly(G)) sequence with the quadruplex-targeting triazole-linked acridine ligand GL15 were investigated using atomic force microscopy (AFM) at a highly oriented pyrolytic graphite and voltammetry at a glassy carbon electrode. GL15 interacted with both sequences, in a time dependent manner, and G-quadruplex formation was detected. AFM showed the adsorption of quadruplexes as small d(TG4T) and poly(G) spherical aggregates and large quadruplex-based poly(G) assemblies, and voltammetry showed the decrease and disappearance of GL15 and guanine oxidation peak currents and appearance of the G-quadruplex oxidation peak. The GL15 molecule strongly stabilized and accelerated G-quadruplex formation in both Na+ and K+ ion-containing solution, although only K+ promoted the formation of perfectly aligned tetra-molecular G-quadruplexes. The small-molecule complex with the d(TG4T) quadruplex is discrete and approximately globular, whereas the G-quadruplex complex with poly(G) is formed at a number of points along the length of the polynucleotide, analogous to beads on a string.