Department of Laboratory Medicine, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing, 400038, China; Key Laboratory of Laboratory Medical Diagnostics, Ministry of Education, Department of Laboratory Medicine, Chongqing Medical University, Chongqing, 400016, China.
Department of Laboratory Medicine, Southwest Hospital, Army Medical University (Third Military Medical University), Chongqing, 400038, China.
Biosens Bioelectron. 2021 Apr 1;177:112981. doi: 10.1016/j.bios.2021.112981. Epub 2021 Jan 8.
Molecular machines constructed by three-dimensional (3-D) DNA walker have emerged as a hot topic in applications such as novel biosensors, cargo delivery platforms and intracellular imaging. Herein, we first propose a lame DNA walker that can randomly and autonomously move on microsphere-based 3-D track. The stochastic lame walker has a long leg mainly responsible for persistent movement and a short leg cutting substrates rapidly. Its motion is propelled by a nicking endonuclease cleavage of hybridized DNA tracks. Kinetic and persistent study show that the lame DNA walker enables reaction equilibrium at 30 min, need a cleat domain of at least 14 nucleotides and can persistently move on 3-D tracks with an average rate of 6.467 × 10 M s. We also demonstrate that the lame walker can be used to detect target DNA in the detection range of 10 pM-5 nM with high specificity by toehold exchange mechanism. This work will further expand the performance of 3-D DNA walkers and substantially contributes to the improved understanding of DNA walking systems.
由三维 (3-D) DNA walker 构建的分子机器在新型生物传感器、货物输送平台和细胞内成像等应用中成为热门话题。在此，我们首次提出了一种 lame DNA walker，它可以在基于微球的 3-D 轨道上随机且自主地移动。随机 lame DNA walker 有一条主要负责持续运动的长腿和一条快速切割底物的短腿。其运动由杂交 DNA 轨道的缺口内切酶切割推动。动力学和持久性研究表明，lame DNA walker 可以在 30 分钟内达到反应平衡，需要至少 14 个核苷酸的 cleat 结构域，并且可以以 6.467×10^-6 M/s 的平均速度在 3-D 轨道上持续移动。我们还通过链置换机制证明，该 lame walker 可以用于检测 10 pM-5 nM 检测范围内的靶 DNA，具有很高的特异性。这项工作将进一步扩展 3-D DNA walker 的性能，并对 DNA 行走系统的深入理解做出重要贡献。
