Conformation- and phosphorylation-dependent electron tunnelling across self-assembled monolayers of tau peptides

Ali Akbar Ashkarran, Atiyeh Hosseini, Reza Loloee, George Perry, Ki Bum Lee, Mikael Lund, Mohammad Reza Ejtehadi, Morteza Mahmoudi

Research output: Contribution to journalArticlepeer-review

2 Scopus citations

Abstract

We report on charge transport across self-assembled monolayers (SAMs) of short tau peptides by probing the electron tunneling rates and quantum mechanical simulation. We measured the electron tunneling rates across SAMs of carboxyl-terminated linker molecules (C6H12O2S) and short cis-tau (CT) and trans-tau (TT) peptides, supported on template-stripped gold (AuTS) bottom electrode, with Eutectic Gallium-Indium (EGaIn)(EGaIn) top electrode. Measurements of the current density across thousands of AuTS/linker/tau//Ga2O3/EGaIn single-molecule junctions show that the tunneling current across CT peptide is one order of magnitude lower than that of TT peptide. Quantum mechanical simulation demonstrated a wider energy bandgap of the CT peptide, as compared to the TT peptide, which causes a reduction in its electron tunneling current. Our findings also revealed the critical role of phosphorylation in altering the charge transport characteristics of short peptides; more specifically, we found that the presence of phosphate groups can reduce the energy band gap in tau peptides and alter their electrical properties. Our results suggest that conformational and phosphorylation of short peptides (e.g., tau) can significantly change their charge transport characteristics and energy levels.

Original languageEnglish (US)
Pages (from-to)2038-2050
Number of pages13
JournalJournal of Colloid And Interface Science
Volume606
DOIs
StatePublished - Jan 15 2022

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Biomaterials
  • Surfaces, Coatings and Films
  • Colloid and Surface Chemistry

Keywords

  • Charge transport
  • Cis-tau peptide
  • Conformation
  • Phosphorylation
  • Quantum mechanical simulation
  • Trans-tau peptide

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