Unravelling Structural Dynamics within a Photoswitchable Single Peptide: A Step Towards Multimodal Bioinspired Nanodevices

Abstract

The majority of the protein structures have been elucidated under equilibrium conditions. The aim herein is to provide a better understanding of the dynamic behavior inherent to proteins by fabricating a label‐free nanodevice comprising a single‐peptide junction to measure real‐time conductance, from which their structural dynamic behavior can be inferred. This device contains an azobenzene photoswitch for interconversion between a well‐defined cis, and disordered trans isomer. Real‐time conductance measurements revealed three distinct states for each isomer, with molecular dynamics simulations showing each state corresponds to a specific range of hydrogen bond lengths within the cis isomer, and specific dihedral angles in the trans isomer. These insights into the structural dynamic behavior of peptides may rationally extend to proteins. Also demonstrated is the capacity to modulate conductance which advances the design and development of bioinspired electronic nanodevices.

Photoisomerization effects in molecular devices

“…众所周知，所有的蛋白质都是连续运动的动态结构，原子受其所在的环境影响而经历 随机的热波动和微小的构象变化 [65] 。 然而，大多数蛋白质结构是在平衡条件下被阐明，对其 结构动态特性了解有限 [66] 。为了进一步理解运动中的结构化/非结构化蛋白质，需要建立一 个完善的体系来测量它们的物理性质，从而推断它们的结构动态行为。由于蛋白质的内在 复杂性，不利于直接研究，本工作采用模型单肽制备无标记单分子器件来测量实时电导， 可以更好地理解蛋白质固有的动态行为，并据此推断其结构动态行为 [67] [67] (网络版彩图)…”