1 research outputs found
Bioengineering a Single-Protein Junction
Bioelectronics
moves toward designing nanoscale electronic platforms
that allow <i>in vivo</i> determinations. Such devices require
interfacing complex biomolecular moieties as the sensing units to
an electronic platform for signal transduction. Inevitably, a systematic
design goes through a bottom-up understanding of the structurally
related electrical signatures of the biomolecular circuit, which will
ultimately lead us to tailor its electrical properties. Toward this
aim, we show here the first example of bioengineered charge transport
in a single-protein electrical contact. The results reveal that a
single point-site mutation at the docking hydrophobic patch of a Cu-azurin
causes minor structural distortion of the protein blue Cu site and
a dramatic change in the charge transport regime of the single-protein
contact, which goes from the classical Cu-mediated two-step transport
in this system to a direct coherent tunneling. Our extensive spectroscopic
studies and molecular-dynamics simulations show that the proteinsā
folding structures are preserved in the single-protein junction. The
DFT-computed frontier orbital of the relevant protein segments suggests
that the Cu center participation in each protein variant accounts
for the different observed charge transport behavior. This work is
a direct evidence of charge transport control in a protein backbone
through external mutagenesis and a unique nanoscale platform to study
structurally related biological electron transfer