Magnetic interactions in small fragments of DNA base pairs

MARTINEZ, F.A.; ADLER, NATALIA S; CAVASOTTO, CLAUDIO N; AUCAR, GUSTAVO A.

St. Simons Island, GA

Simposio; 59th Sanibel Symposium; 2019

DNA electronic interactions along the plane of the base pairs are transmitted through hydrogen-bonds (HBs), and perpendicular to it are mainly given by stacking. The knowledge of the latter is 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 was 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/B97D/6-311++G(d,p) level of theory, and the DNA fragment was taken from the Protein Data Bank (PDB ID 1BNA). We analyze the effects of both stacking and solvent, and we found different patterns of variations for the shieldings of external and internal atoms