Spin transport in a methylated DNA molecule sandwiched between ferromagnetic electrodes was examined based on the Landauer formula with the first-principles approximation. Although methylation increased the conductance of the DNA molecule, the raised width was very small to be discriminated using an analytical method. Contrastingly, cytosine methylation affected spin polarization, resulting in more than 10% change in the ratio of magnetoresistance. The change in magnetoresistance was enhanced with a certain degree of cytosine methylation, whereas segregated cytosine methylation was unable to induce a detectable change in the magnetoresistance. These results suggest the possibility of elucidating the relationship between cytosine methylation and epigenetics by assessing magnetoresistance in a DNA molecule in the future.

基于第一原理近似的Landauer公式检查了夹在铁磁电极之间的甲基化DNA分子中的自旋运输。尽管甲基化增加了DNA分子的电导率，但增加的宽度很小，无法使用分析方法进行区分。相反，胞嘧啶甲基化影响自旋极化，导致磁阻比变化超过10％。磁致电阻的变化随一定程度的胞嘧啶甲基化而增强，而分离的胞嘧啶甲基化无法诱导可检测的磁阻变化。这些结果表明将来有可能通过评估DNA分子中的磁阻来阐明胞嘧啶甲基化与表观遗传学之间的关系。