Magnetic Properties of Natural and Modified DNAs
Chang Hoon Lee, Eui-Doo Do, Young-Wan Kwon, Dong-Hoon Choi, Jung-Il Jin, Dong-Keun Oh, Hiroyuki Nishide and Takashi Kurata
Natural DNAs in dry state, i.e., A-DNAs, when intercalated with lowlevels of stable organic free radicals or complexed with low levels of Au(III), are attracted at room temperature to commercial magnets, whereas those containing high levels of intercalators or Au(III) are not. This surprising observation is explained by the EPR spectra and SQUID measurement of magnetization of the modified DNAs. It is conjectured that A-DNAs are morphologically heterogeneous containing ordered and disordered regions. The ordered regions appear to strongly mediate magnetic interactions between spins through their pz -stacked structures. When the modified DNAs are wet or hydrated, they behave diamagnetically.