Protein Binding and Orientation Matter: Bias-Induced Conductance Switching in a Mutated Azurin Junction.

ABSTRACT: We observe reversible, bias-induced switching of conductance via a blue copper protein azurin mutant, N42C Az, with a nearly 10-fold increase at |V| > 0.8 V than at lower bias. No such switching is found for wild-type azurin, WT Az, up to |1.2 V|, beyond which irreversible changes occur. The N42C Az mutant will, when positioned between electrodes in a solid-state Au-protein-Au junction, have an orientation opposite that of WT Az with respect to the electrodes. Current(s) via both proteins are temperature-independent, consistent with quantum mechanical tunneling as dominant transport mechanism. No noticeable difference is resolved between the two proteins in conductance and inelastic electron tunneling spectra at <|0.5 V| bias voltages. Switching behavior

SUBMITTER: Fereiro JA 

PROVIDER: S-EPMC7662909 | biostudies-literature | 2020 Nov

REPOSITORIES: biostudies-literature