STUDIES or RNA AND DNA HAIRPIN INTERACTIONS WITH MINERAL SURFACE: IMPLICATIONS FOR MOLECULES IN METEORITES AND MARTIAN SAMPLES

摘要

In previous studies, we have shown that Surface-Enhanced Spectroscopy (SERS) using silver colloids as adsorbent phase allows studying picomoles of DNA or RNA nucleic acids standing at the solid-liquide interface. The most important underlined feature was the use of the adenyl groups as probes of nucleic acid reactivity with minerals. In this report, we present the silver phase as a model for electron-depleted mineral surfaces that may be encountered in terrestrial soils. In a first approach, we focus on the adsorption of adenyl residues included in four species of DNA loops with three residues or in the eight GNRA RNA tetraloops. They could be considered as in vitro models to test nucleic acid adsorption mechanisms and also to enlighten potential structural and reactivity changes that may be entailed. Our study underlines that primary sequences and local structures monitor the reactivity of adenyl residues involved in loops, whether made of DNA or RNA. Such investigations on very small amount of nucleic acid materials could serve in the area of searching living molecules adsorbed on long live terrestrial materials or in extraterrestrial rocks.