Equilibrium and non-equilibrium furanose selection in the ribose isomerisation network

Avinash Vicholous Dass (1) , Thomas Georgelin (1) , Frances Westall (1) , Frédéric Foucher (1) , Paolo de Los Rios (2) , Daniel Maria Busiello (2) , Shiling Liang (2) , Francesco Piazza (1)

1 CBM - Centre de biophysique moléculaire
2 EPFL - Ecole Polytechnique Fédérale de Lausanne

The exclusive presence of β-D-ribofuranose in nucleic acids is still a conundrum in prebiotic chemistry, given that pyranose species are substantially more stable at equilibrium. However, a precise characterisation of the relative furanose/pyranose fraction at temperatures higher than about 50 °C is still lacking. Here, we employ a combination of NMR measurements and statistical mechanics modelling to predict a population inversion between furanose and pyranose at equilibrium at high temperatures. More importantly, we show that a steady temperature gradient may steer an open isomerisation network into a non-equilibrium steady state where furanose is boosted beyond the limits set by equilibrium thermodynamics. Moreover, we demonstrate that nonequilibrium selection of furanose is maximum at optimal dissipation, as gauged by the temperature gradient and energy barriers for isomerisation. The predicted optimum is compatible with temperature drops found in hydrothermal vents associated with extremely fresh lava flows on the seafloor.

Domaines: Sciences du Vivant [q-bio]

Avinash Vicholous Dass, Thomas Georgelin, Frances Westall, Frédéric Foucher, Paolo de Los Rios, et al.. Equilibrium and non-equilibrium furanose selection in the ribose isomerisation network. Nature Communications, 2021, 12 (1), pp.2749. ⟨10.1038/s41467-021-22818-5⟩. ⟨hal-03229691⟩