title: Hydration regulates the thermodynamic stability of DNA structures under molecular crowding conditions.
abstract: Although water is an integral part of DNA structures, the effects of water molecules on various DNA structures which are formed by not only Watson-Crick but also Hoogsteen base pairs are still unclear. Here, we studied quantitatively the effects of molecular crowding on the thermodynamics of a parallel G-quadruplex formation of [d(TG 4)2]4 with Hoogsteen base pairs. It was demonstrated that molecular crowding conditions stabilized the parallel G-quadruplex. Moreover, the plot of stability of the parallel G-quadruplex structure versus water activity suggested that water molecules were released through the G-quadruplex formation. The stabilization of the DNA structures consisting of Hoogsteen base pairs under cell-like conditions may lead to a structural polymorphism of various DNA sequences regulated by water molecules.
authors: Frontier Institute for Biomolecular Engineering Research, Konan University, Higashinada-ku, Kobe, Japan.
authors: Daisuke
authors: D
authors: Miyoshi
authors: Hisae
authors: H
authors: Karimata
authors: Naoki
authors: N
authors: Sugimoto
mesh_terms: D001483:Base Sequence; D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry*; D054856:G-Quadruplexes; D009691:Nucleic Acid Denaturation / Q000528:radiation effects; D013816:Thermodynamics; D014466:Ultraviolet Rays; D014867:Water / Q000737:chemistry*
chemical_list: D014867:Water; D004247:DNA