Binding-Induced Diversity of a Human Telomeric G-Quadruplex Stability Phase Space.

ABSTRACT: The structural polymorphism of G-quadruplex nucleic acids is an important factor in their recognition by proteins and small-molecule ligands. However, it is not clear why the binding of several ligands alters G-quadruplex topology. We addressed this question by following the (un)folding and binding of the human telomeric fragment 5'-(GGGTTA)₃GGGT-3' (22GT) by calorimetry (DSC, ITC) and spectroscopy (CD). A thermodynamic analysis of the obtained data led to a detailed description of the topological phase space of stability (phase diagram) of 22GT and shows how it changes in the presence of a specific bisquinolinium ligand (360A). Various 1:1 and 2:1 ligand-quadruplex complexes were observed. With increasing temperature, the 1:1 complexes transformed into 2:1 complexes, which is a

SUBMITTER: Oblak D 

PROVIDER: S-EPMC9501445 | biostudies-literature | 2022 Sep

REPOSITORIES: biostudies-literature