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Aucar_Gustavo_1

Magnetic interactions in small fragments of DNA base pairs

Fernando A. Martinez1 , Natalia Adler2 , Claudio Cavasotto2,3,4 and Gustavo A. Aucar1

1 Natural and Exact Science Faculty, Northeastern University of Argentina and IMIT-CONICET, Avda Libertad 5460, Corrientes, Argentina. 2 Translational Medicine Research Institute (IIMT), CONICETAustral, Pilar-Derqui, Buenos Aires, Argentina. 3 Facultad de Ciencias Biomédicas and 4 Facultad de Ingeniería, Universidad Austral, Pilar-Derqui, Buenos Aires, Argentina

 

DNA electronic interactions along the plane of the base pairs are transmitted through hydrogenbonds, and perpendicular to it are mainly given by stacking. The knowledge of these last interactions are important for understanding the stacking forces necessary to break fragments of DNA base-pairs while leaving HBs intact.

Most of previous studies on the electronic interactions between fragments of DNA are related to electronic energies, charge distributions and electronic properties. The analysis of magnetic properties were recently published by our group of research and here we will show an extension of those studies that consider the effect of explicit or implicit solvent on the NMR magnetic shieldings of nitrogen, carbon and hydrogen atoms. Calculations were performed at the DFT/wB97XD/6-311++G(d,p) level of theory and the fragment was taken from the Protein Data Bank (PDB ID; 1BNA). We analyze the effect of both, stacking and solvent. We found different patterns of variations for the shieldings of external and internal atoms.