Probing Residual Water in G-Quadruplex Structures through Molecular Vibrations.

ABSTRACT: G-quadruplexes (GQs), noncanonical DNA structures involved in gene regulation and genome stability, exhibit a high structural polymorphism that is strongly modulated by their solvation environment. Here we employ a dual-spectroscopy approach, combining ultraviolet resonance Raman (UVRR) scattering with circular dichroism (CD), to study GQ dilute solutions during thermal unfolding. UVRR scattering enhances the vibrational features of GQs, providing a method previously applied to other biosystems but novel for GQs in probing solute-solvent interactions. By analyzing the O-H stretching vibrational band, which reflects the hydrogen-bonded water network, we reveal how water molecules interact differently with two distinct GQ conformers, namely, hybrid and parallel. We demonstrate that coupling

SUBMITTER: Libera V 

PROVIDER: S-EPMC12498502 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature