Selectivity of small molecule ligands for parallel and anti-parallel DNA G-quadruplex structures.
Org Biomol Chem
; 7(20): 4194-200, 2009 Oct 21.
Article
em En
| MEDLINE
| ID: mdl-19795057
ABSTRACT
We report CD, ESI-MS and molecular modelling studies of ligand binding interactions with DNA quadruplex structures derived from the human telomeric repeat sequence (h-Tel) and the proto-oncogenic c-kit promoter sequence. These sequences form anti-parallel (both 2 + 2 and 3 + 1) and parallel conformations, respectively, and demonstrate distinctively different degrees of structural plasticity in binding ligands. With h-Tel, we show that an extended heteroaromatic 1,4-triazole (TRZ), designed to exploit pi-stacking interactions and groove-specific contacts, shows some selectivity for parallel folds, however, the polycyclic fluorinated acridinium cation (RHPS4), which is a similarly potent telomerase inhibitor, shows selectivity for anti-parallel conformations implicating favourable interactions with lateral and diagonal loops. In contrast, the unique c-kit parallel-stranded quadruplex shows none of the structural plasticity of h-Tel with either ligand. We show by quantitative ESI-MS analysis that both sequences are able to bind a ligand on either end of the quadruplex. In the case of h-Tel the two sites have similar affinities, however, in the case of the c-kit quadruplex the affinities of the two sites are different and ligand-dependent. We demonstrate that two different small molecule architectures result in significant differences in selectivity for parallel and anti-parallel quadruplex structures that may guide quadruplex targeted drug-design.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Triazóis
/
Acridinas
/
DNA
/
Quadruplex G
Tipo de estudo:
Prognostic_studies
Limite:
Humans
Idioma:
En
Revista:
Org Biomol Chem
Assunto da revista:
BIOQUIMICA
/
QUIMICA
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
Reino Unido