Berlin 2018 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 9: Postersession I

BP 9.31: Poster

Montag, 12. März 2018, 17:30–19:30, Poster A

Gas bubbles in thermal gradients accumulate DNA and trigger wet-dry cycles — •Matthias Morasch, Jonathan Liu, Christof Mast, and Dieter Braun — LMU Munich, Amalienstr. 54, 80799 München, Germany

Life has developed in water, but dry steps are essential for many prebiotically plausible syntheses and polymerization processes [1,2]. This posits the question how dry-wet cycles can be combined with an underwater scenario without diluting the reaction products into the ocean. We found that a nonequilibrium system in form of a temperature gradient across a gas bubble in water creates an efficient accumulation setting. In addition to the known thermophoretic trap, molecules hereby strongly accumulate at the water-gas interface [3]. Movements of the gas bubble thereby trigger continuous drying and re-hydration steps, while maintaining high local concentrations of ca. 1000-fold near the interface. Here, we show the underlying mechanisms for the accumulation process at the water-air interface, which also exhibits a length-selectivity e.g. for DNA strands. In addition, we demonstrate the precipitation and redilution of RNA monomers that polymerize only under dry conditions [2]. This mechanism allows reaction pathways such as the formation, phosphorylation, or polymerization of nucleotides that require both aqueous and dry conditions.

[1] Powner et al., (2009) Nature 459:239-242. [2] Morasch et al (2014) ChemBioChem 15:879-883. [3] Braun et al. (in submission)