Amino Acid Sequence Controls Enhanced Electron Transport in Heme-Binding Peptide Monolayers

作者：Hao Yang, Xiaolin Liu, Moeen Meigooni, Li Zhang, Junjiang Ren, Qian Chen, Mark D. Losego, Emad Tajkhorshid, Jeffrey S. Moore, Charles M. Schroeder · 发表于：ACS Central Science · 年份：2025 · DOI：10.1021/acscentsci.4c01849 · 被引用次数：8 · 研究领域：Molecular Junctions and Nanostructures、Quantum Dots Synthesis And Properties、Neuroscience and Neural Engineering

High Resolution Image Download MS PowerPoint Slide Metal-binding proteins have the exceptional ability to facilitate long-range electron transport in nature. Despite recent progress, the sequence-structure–function relationships governing electron transport in heme-binding peptides and protein assemblies are not yet fully understood. In this work, the electronic properties of a series of heme-binding peptides inspired by cytochrome bc 1 are studied using a combination of molecular electronics experiments, molecular modeling, and simulation. Self-assembled monolayers (SAMs) are prepared using sequence-defined heme-binding peptides capable of forming helical secondary structures. Following monolayer formation, the structural properties and chemical composition of assembled peptides are determined using atomic force microscopy and X-ray photoelectron spectroscopy, and the electronic properties (current density–voltage response) are characterized using a soft contact liquid metal electrode method based on eutectic gallium–indium alloys (EGaIn). Our results show a substantial 1000-fold increase in current density across SAM junctions upon addition of heme compared to identical peptide sequences in the absence of heme, while maintaining a constant junction thickness. These findings show that amino acid composition and sequence directly control enhancements in electron transport in heme-binding peptides. Overall, this study demonstrates the potential of using sequence-defined synthe...