Zotti Linda A, Cuevas Juan Carlos
Departamento de Física Teórica de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, Ciudad Universitaria de Cantoblanco, E-28049 Madrid, Spain.
ACS Omega. 2018 Apr 3;3(4):3778-3785. doi: 10.1021/acsomega.7b01917. eCollection 2018 Apr 30.
Motivated by recent experiments, we performed a theoretical study of electron transport through single-molecule junctions incorporating four kinds of homopeptides (based on alanine, glutamic acid, lysine, and tryptophan). Our results suggest that these molecules are rather insulating and operate in off-resonance tunneling as their main transport mechanism. We ascribe their poor performance as conductors to the high localization of their frontier orbitals. We found that binding scenarios in which side chains lie on the side of gold protuberances could give rise to an increase in conductance with respect to end-to-end binding configurations. These findings provide an insight into the conductance mechanism of the building blocks of proteins and identify key issues that need to be further investigated.
受近期实验的启发，我们对通过包含四种同型肽（基于丙氨酸、谷氨酸、赖氨酸和色氨酸）的单分子结的电子传输进行了理论研究。我们的结果表明，这些分子相当绝缘，并且以非共振隧穿作为其主要传输机制。我们将它们作为导体的性能不佳归因于其前沿轨道的高度局域化。我们发现，侧链位于金凸起侧面的结合情况相对于端对端结合构型可能会导致电导率增加。这些发现为蛋白质构建块的导电机制提供了见解，并确定了需要进一步研究的关键问题。
