6sx3

Publication Abstract from PubMed

G-rich oligonucleotide VK2 folds into an AGCGA-quadruplex, tetrahelical structure distinct and significantly different from G-quadruplexes, even though it contains four G3-tracts. Herein, we show that a bis-quinolinium ligand 360A with high affinity for G-quadruplex structures and selective telomerase inhibition, strongly binds to VK2. Upon binding, 360A does not induce a conformational switch from VK2 to an expected G-quadruplex. In contrast, NMR structural study revealed formation of a well-defined VK2-360A complex with a 1:1 binding stoichiometry, where 360A intercalates between GAGA- and GCGC-quartets in the central cavity of VK2. This is the first high-resolution structure of a G-quadruplex ligand intercalating into a G-rich tetrahelical fold. Unique mode of ligand binding into tetrahelical DNA architecture offers insights into stabilization of an AGCGA-quadruplex by a heterocyclic ligand and provides guidelines for rational design of novel VK2 binding molecules with selectivity for different DNA secondary structures.

Intercalation of heterocyclic ligand between quartets in G-rich tetrahelical structure.,Plavec J, Kocman V, Kotar A Chemistry. 2019 Nov 21. doi: 10.1002/chem.201904923. PMID:31750579^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.