Conductance of alpha-helical peptides trapped within molecular junctions.
Self-assembled monolayers of alpha-helical peptides on a gold surface were employed as model systems for the investigation of mediated electron transfer. The peptides contained 14, 15, 16, and 17 amino acid residues. The measurements of electron transmission through single molecules of helical peptides were performed using scanning tunneling spectroscopy (STS). The molecules were trapped between the gold tip and the substrate. Electrical contact between the molecule and the gold probe was achieved by the use of peptides containing thiol groups present at each end of the helix. The conductance behavior of the peptides was examined as a function of tip-substrate distance at fixed bias voltage. Measurements performed with peptides containing different numbers of amino acid residues indicate that the distance dependence of electron transmission through an alpha-helix is weaker than that through simple n-alkyl bridges.
Sek
Slawomir
S
Department of Chemistry, University of Warsaw, Pasteura 1, 02093 Warsaw, Poland. slasek@chem.uw.edu.pl
Misicka
Aleksandra
A
Swiatek
Karolina
K
Maicka
Elwira
E
D000595:Amino Acid Sequence; D001703:Biophysics / Q000379:methods*; D002627:Chemistry, Physical / Q000379:methods*; D004563:Electrochemistry; D004583:Electrons; D016252:Microscopy, Scanning Tunneling; D008968:Molecular Conformation; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry*; D017433:Protein Structure, Secondary; D011506:Proteins / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties
D010455:Peptides; D011506:Proteins