Microcalorimetric determination of thermodynamic stability of RNA triplex

Author: Mgr. Martina Říhová
Supervisor: Prof. RNDr. Josef Štěpánek, CSc.
Type: Bachelor

Abstract: The work is devoted to thermodynamic characterization of ribonucleic acid duplexes and triplexes. The complex formation and dissociation was investigated by using a differential scanning microcalorimeter. Mixed solutions of synthetic RNA homopolymers, polyA a polyU, in various stoichiometric ratios were used as the samples. From the data collected, corresponding enthalpy ΔH and entropy ΔS changes, and a melting temperature were determined. The results showed that in the case of our measurements the obtained characteristics were systematically shifted in the course of repeated scans. This phenomenon seems to be related to RNA interaction with the measuring cell surface, and is thus considerable from the viewpoint of the scanning microcalorimetry applicability to quantitative thermodynamic studies of RNA. The melting temperature changes induced by magnesium addition revealed that its effect causes increased complex stabilization when the third chain is bound to the duplex.

Keywords: RNA triplex, RNA duplex, microcalorimetry, Thermodynamic characteristics, melting temperature.