Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands.
Nanoscale. 2021 Feb 7;13(5):3002-3009. doi: 10.1039/d0nr08556a. Epub 2021 Jan 28.
We report on charge transport across single short peptides using the Mechanically Controlled Break Junction (MCBJ) method. We record thousands of electron transport events across single-molecule junctions and with an unsupervised machine learning algorithm, we identify several classes of traces with multifarious conductance values that may correspond to different peptide conformations. Data analysis shows that very short peptides, which are more rigid, show conductance plateaus at low conductance values of about 10G and below, with G being the conductance quantum, whereas slightly longer, more flexible peptides also show plateaus at higher values. Fully stretched peptide chains exhibit conductance values that are of the same order as that of alkane chains of similar length. The measurements show that in the case of short peptides, different compositions and molecular lengths offer a wide range of junction conformations. Such information is crucial to understand mechanism(s) of charge transport in and across peptide-based biomolecules.
我们使用机械控制断接（MCBJ）方法报告了单个短肽的电荷传输情况。我们在单分子结上记录了数千个电子输运事件，并使用无监督机器学习算法，我们识别出了具有多种电导值的多个轨迹类别，这些类别可能对应于不同的肽构象。数据分析表明，更刚性的非常短的肽在约 10G 及以下的低电导值处表现出电导平台，其中 G 是电导量子，而稍长的、更灵活的肽在更高的值处也表现出平台。完全拉伸的肽链表现出与相似长度的烷烃链相同数量级的电导值。这些测量结果表明，在短肽的情况下，不同的组成和分子长度提供了广泛的结构构象。这些信息对于理解基于肽的生物分子内部和之间的电荷传输机制至关重要。
