Department of Physics, Wenzhou University, Wenzhou 325035, China.
Department of Physics, Wenzhou University, Wenzhou 325035, China.
Int J Biol Macromol. 2022 Jun 15;210:292-299. doi: 10.1016/j.ijbiomac.2022.04.182. Epub 2022 May 6.
Lanthanide (Ln) cations exhibit unique properties that include the ability to interact with DNA to form metal-DNA complexes, which are of great interest in medical, biological and nano-technological fields. Both experimental and theoretical studies have not completely addressed the interaction dynamics between lanthanide ions and DNA. The present study investigates the dynamics of the Ln-DNA interaction at the level of a single DNA molecule. Different DNA-metal complexes were produced by the addition of the five lanthanide ions, La, Ce, Pr, Tb, and Ho to the DNA solutions. The binding dynamics indicated that the lanthanide cations can induce DNA compaction in a concentration and force-dependent manner. Ionic specificity was displayed in the single-molecule interaction dynamics, where, Ho was found to be the most efficient lanthanide to cause DNA compaction, which was verified by the morphological characterization. The DNA molecules in the five Ln-DNA complex solutions were restored to their original length with different restoration speeds, by the addition of EDTA, and this further indicated that the Ho ion had the strongest affinity toward DNA. We conclude that counterion correlation cannot solely explain the ion-dependent DNA compaction, and ionic specificity should be considered significant.
镧系元素 (Ln) 阳离子具有独特的性质，包括与 DNA 相互作用形成金属-DNA 配合物的能力，这在医学、生物学和纳米技术领域具有重要意义。实验和理论研究都没有完全解决镧系离子与 DNA 之间的相互作用动力学。本研究在单个 DNA 分子水平上研究了 Ln-DNA 相互作用的动力学。通过向 DNA 溶液中加入五种镧系离子（La、Ce、Pr、Tb 和 Ho），产生了不同的 DNA-金属配合物。结合动力学表明，镧系阳离子可以以浓度和力依赖的方式诱导 DNA 紧缩。单分子相互作用动力学显示出离子特异性，其中 Ho 被发现是最有效地引起 DNA 紧缩的镧系离子，这通过形态特征得到了验证。通过添加 EDTA，五种 Ln-DNA 配合物溶液中的 DNA 分子恢复到其原始长度，恢复速度不同，这进一步表明 Ho 离子与 DNA 的亲和力最强。我们得出结论，抗衡离子相关性不能单独解释离子依赖性 DNA 紧缩，应该考虑离子特异性。
