title: Single-molecule mapping of long-range electron transport for a cytochrome b(562) variant.
abstract: Cytochrome b(562) was engineered to introduce a cysteine residue at a surface-exposed position to facilitate direct self-assembly on a Au(111) surface. The confined protein exhibited reversible and fast electron exchange with a gold substrate over a distance of 20 Å between the heme redox center and the gold surface, a clear indication that a long-range electron-transfer pathway is established. Electrochemical scanning tunneling microscopy was used to map electron transport features of the protein at the single-molecule level. Tunneling resonance was directly imaged and apparent molecular conductance was measured, which both show strong redox-gated effects. This study has addressed the first case of heme proteins and offered new perspectives in single-molecule bioelectronics.
authors.affiliation: School of Physics and Astronomy, Cardiff University, Queens's Building, The Parade, Cardiff CF24 3AA, U.K.
authors.forename: Eduardo Antonio Della
authors.initials: EA
authors.lastname: Pia
authors.forename: Qijin
authors.initials: Q
authors.lastname: Chi
authors.forename: D Dafydd
authors.initials: DD
authors.lastname: Jones
authors.forename: J Emyr
authors.initials: JE
authors.lastname: Macdonald
authors.forename: Jens
authors.initials: J
authors.lastname: Ulstrup
authors.forename: Martin
authors.initials: M
authors.lastname: Elliott
mesh_terms: D003545:Cysteine / Q000737:chemistry / Q000235:genetics; D003573:Cytochrome b Group / Q000737:chemistry* / Q000235:genetics; D004563:Electrochemistry; D004579:Electron Transport; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics; D006046:Gold / Q000737:chemistry*; D016252:Microscopy, Scanning Tunneling / Q000379:methods*; D010084:Oxidation-Reduction; D015202:Protein Engineering
chemical_list: D003573:Cytochrome b Group; D029968:Escherichia coli Proteins; D006046:Gold; C017850:cytochrome b562, E coli; D003545:Cysteine