Dresden 2006 – wissenschaftliches Programm
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CPP: Chemische Physik und Polymerphysik
CPP 12: POSTER Colloids, Nanoparticles and Self-Organizing Systems
CPP 12.28: Poster
Dienstag, 28. März 2006, 17:00–19:00, P3
Characterization of Short-lived Radicals of Purine Bases in Aqueous Solution by Magnetic Resonance — •Alexey Kiryutin1,2, Konstantin Ivanov2, and Hans-Martin Vieth1 — 1Department of Physics, Free University of Berlin, Arnimallee 14, D-14195 Berlin, Germany — 2International Tomography Center of SB RAS, 630090, Institutskaya 3a, Novosibirsk, Russia
The structure of nucleotide radicals and their properties can be examined by the effects of chemically induced dynamic nuclear polarization (CIDNP) created in reversible photoreactions between nucleotides and suitable organic dye molecules. The CIDNP spectra with microsecond time resolution were obtained in photoreactions between purine bases and several dyes. Usually radical reactions such as protonation, deprotonation and termination occur on the microsecond time scale. The intensity and sign of the CIDNP at the aromatic protons of adenosine 5’-monophosphate and guanosine 5’-monophosphate (AMP, GMP) was studied depending on the dye and pH value of aqueous solution. From the shape of CIDNP spectra different nucleotide radicals were identified. For GMP and AMP the CIDNP was measured at variable magnetic field (0-7 T). From simulation of these field dependencies g-factors of the short-lived neutral, anionic and cationic forms of the nucleotide radicals were determined. These results contribute to the understanding of radical formation of nucleotides. In addition, the use of CIDNP effects for studying the structure of nucleic acids and the mobility of their bases will be discussed.