Electron Transport across Peptides and Proteins
Prof. David Cahen, Weizmann Institute of Science
Electron transport (ETp), i.e., electronic conduction across peptides and proteins in a solid state–like configuration is surprisingly efficient, and comparable to, or at times even more efficient than via completely conjugated molecules of comparable length. Working with modified proteins and with homopeptides we find both cofactors and secondary structure to matter for ETp efficiency. An open question is if contact to the external world is the dominant factor, or intra-protein transport. This is important, also for electron transfer, ET: nature regulates ET via redox chemistry, i.e., injection and extraction of electrons; this is where ET and ETp are related, because the analog in the latter is the coupling to the electrodes. In ET control over the process is achieved at the free energy price of a redox event, but no redox process is required for ETp. This allows studying ETp via non-redox proteins, such as rhodopsins or albumins (“dopable” proteins), pointing to peptides as efficient transport media; studying transport via, including coupling to them, can help to learn about protein ETp.