Thorneywork Alice L, Gladrow Jannes, Qing Yujia, Rico-Pasto Marc, Ritort Felix, Bayley Hagan, Kolomeisky Anatoly B, Keyser Ulrich F
Cavendish Laboratory, University of Cambridge, Cambridge, CB3 0HE, UK.
Department of Chemistry, University of Oxford, Oxford OX1 3TA, UK.
Sci Adv. 2020 May 1;6(18):eaaz4642. doi: 10.1126/sciadv.aaz4642. eCollection 2020 May.
All natural phenomena are governed by energy landscapes. However, the direct measurement of this fundamental quantity remains challenging, particularly in complex systems involving intermediate states. Here, we uncover key details of the energy landscapes that underpin a range of experimental systems through quantitative analysis of first-passage time distributions. By combined study of colloidal dynamics in confinement, transport through a biological pore, and the folding kinetics of DNA hairpins, we demonstrate conclusively how a short-time, power-law regime of the first-passage time distribution reflects the number of intermediate states associated with each of these processes, despite their differing length scales, time scales, and interactions. We thereby establish a powerful method for investigating the underlying mechanisms of complex molecular processes.
所有自然现象均受能量景观的支配。然而，对这一基本量的直接测量仍然具有挑战性，尤其是在涉及中间态的复杂系统中。在这里，我们通过对首次通过时间分布的定量分析，揭示了支撑一系列实验系统的能量景观的关键细节。通过对受限胶体动力学、通过生物孔的传输以及DNA发夹的折叠动力学的联合研究，我们确凿地证明了首次通过时间分布的短时间幂律 regime 如何反映与这些过程中的每一个相关的中间态数量，尽管它们的长度尺度、时间尺度和相互作用各不相同。我们由此建立了一种强大的方法来研究复杂分子过程的潜在机制。
