Monolayers of a de novo designed 4-alpha-helix bundle carboprotein and partial structures on Au(111)-surfaces.
Mapping of structure and function of proteins adsorbed on solid surfaces is important in many contexts. Electrochemical techniques based on single-crystal metal surfaces and in situ scanning probe microscopies (SPM) have recently opened new perspectives for mapping at the single-molecule level. De novo design of model proteins has evolved in parallel and holds promise for test and control of protein folding and for new tailored protein structural motifs. These two strategies are combined in the present report. We present a synthetic scheme for a new 4-alpha-helix bundle carboprotein built on a galactopyranoside derivative with a thiol anchor aglycon suitable for surface immobilization on gold. The galactopyranoside with thiol anchor and the thiol anchor alone were prepared for comparison. Voltammetry of the three molecules on Au(111) showed reductive desorption peaks caused by monolayer adsorption via thiolate-Au bonding. In situ STM of the thiol anchor disclosed an ordered adlayer with clear domains and molecular features. This holds promise, broadly for single-molecule voltammetry and the SPM and scanning tunnelling microscopy (STM) of natural and synthetic proteins.
Brask
Jesper
J
Department of Chemistry, Buildings 201 and 207, Technical University of Denmark, DK-2800 Lyngby, Denmark.
Wackerbarth
Hainer
H
Jensen
Knud J
KJ
Zhang
Jingdong
J
Nielsen
Jens U
JU
Andersen
Jens E T
JE
Ulstrup
Jens
J
D004563:Electrochemistry; D004577:Electron Probe Microanalysis; D006046:Gold / Q000737:chemistry*; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry*
D011506:Proteins; D006046:Gold