RT info:eu-repo/semantics/article T1 Unequal effect of ethanol–water on the stability of ct-DNA, poly[(dA–dT)]2 and poly(rA)·poly(rU). Thermophysical properties A1 Ruiz, Rebeca A1 Hoyuelos Álvaro, Fco. Javier A1 Navarro Cuñado, A. Marta A1 Leal Villalba, José María A1 García Ruiz, Begoña K1 DNA K1 RNA K1 Thermophysical properties K1 Ethanol-water K1 Química física K1 Chemistry, Physical and theoretical AB Ethanol affects unequally the thermal stability of DNA and RNA. It stabilizes RNA, while destabilizing DNA. The variation of the relative viscosity (η/η0) of [poly(dA–dT)]2 with temperature unveils transitions close to the respective denaturation temperature, calculated spectrophotometrically and calorimetrically. From the raw data densities and speeds of sound, the volumetric observables were calculated. In all cases studied, a change in sign from low to high ethanol content occurred for both partial molar volume (ϕV) and partial molar adiabatic compressibility (ϕKS). The minima, close to 10%, should correspond to the highest solvation and the maxima, close to 30%, to the lowest solvation. For 40–50% ethanol, the solvation increases again. The complex structure of ethanol–water, for which changes are observed in regions close to such critical concentrations, justifies the observed behaviour. The variation of ϕV and ϕKS was sharper for RNA compared with respect to DNA, indicating that the solvation sequence is poly(rA)·poly(rU) < ct-DNA < [poly(dA–dT)]2. PB Royal Society of Chemistry SN 1463-9076 YR 2015 FD 2015-01 LK http://hdl.handle.net/10259/8226 UL http://hdl.handle.net/10259/8226 LA eng NO The financial support by Junta de Castilla y León (Fondo Social Europeo, project BU-299A12-1) and Obra Social “la Caixa” project OSLC-2012-007, Spain, is gratefully acknowledged. DS Repositorio Institucional de la Universidad de Burgos RD 09-may-2024