DNA Gold Nanoparticle Motors Demonstrate Processive Motion with Bursts of Speed Up to 50 nm Per Second
DNA Gold Nanoparticle Motors Demonstrate Processive Motion with Bursts of Speed Up to 50 nm Per Second
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DOI：
10.1021/acsnano.0c10658
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发表时间：
2021-05-06
期刊：
影响因子：
17.1
通讯作者：
Salaita, Khalid
中科院分区：
文献类型：
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作者：
Bazrafshan, Alisina;Kyriazi, Maria-Eleni;Salaita, Khalid
消耗化学能产生机械功的合成马达在从计算到药物输送和诊断的许多领域提供了潜在的应用。在迄今为止研究的各种合成马达中，基于DNA的机器提供了最大的可编程性，并显示出以自主方式转移微米距离的能力。DNA马达通过采用烧桥布朗棘轮机制移动，其中DNA“腿”杂交，然后破坏固定在表面上的互补核酸。我们之前已经表明，与双足步行者相比，滚动的高度多价DNA马达提供了更好的性能。在这里，我们使用DNA-金纳米颗粒缀合物来研究和增强DNA纳米颗粒的性能。具体来说，我们调整结构参数，如DNA腿密度，腿跨度，和纳米颗粒的各向异性以及缓冲条件，以提高电机性能。建模和实验都表明，增加DNA腿密度提高了马达的速度和持续性，而DNA腿跨度增加了持续性和方向性。通过利用纳米马达的无标记成像，我们还发现了Levy型运动，其中马达表现出易位的爆发，并伴有短暂的失速。二聚化颗粒还表现出更多的弹道轨迹，证实了滚动机制。我们的工作显示了控制DNA马达性能的基本特性，并展示了优化的马达，可以在几分钟内以高达50 nm/s的速度移动多个微米。这些纳米级马达的性能接近以100-1000 nm/s的速度行进的马达蛋白的性能，因此这项工作在开发原细胞系统以及下一代传感器和诊断方面可能是重要的。
Synthetic motors that consume chemical energy to produce mechanical work offer potential applications in many fields that span from computing to drug delivery and diagnostics. Among the various synthetic motors studied thus far, DNA-based machines offer the greatest programmability and have shown the ability to translocate micrometer-distances in an autonomous manner. DNA motors move by employing a burnt-bridge Brownian ratchet mechanism, where the DNA "legs" hybridize and then destroy complementary nucleic acids immobilized on a surface. We have previously shown that highly multivalent DNA motors that roll offer improved performance compared to bipedal walkers. Here, we use DNA-gold nanoparticle conjugates to investigate and enhance DNA nanomotor performance. Specifically, we tune structural parameters such as DNA leg density, leg span, and nanoparticle anisotropy as well as buffer conditions to enhance motor performance. Both modeling and experiments demonstrate that increasing DNA leg density boosts the speed and processivity of motors, whereas DNA leg span increases processivity and directionality. By taking advantage of label-free imaging of nanomotors, we also uncover Levy-type motion where motors exhibit bursts of translocation that are punctuated with transient stalling. Dimerized particles also demonstrate more ballistic trajectories confirming a rolling mechanism. Our work shows the fundamental properties that control DNA motor performance and demonstrates optimized motors that can travel multiple micrometers within minutes with speeds of up to SO nm/s. The performance of these nanoscale motors approaches that of motor proteins that travel at speeds of 100-1000 nm/s, and hence this work can be important in developing protocellular systems as well next generation sensors and diagnostics.