Formation of oriented polypeptides on Au(111) surface depends on the secondary structure controlled by peptide length
✍ Scribed by Toshihiko Sakurai; Sayaka Oka; Atsushi Kubo; Katsuhiko Nishiyama; Isao Taniguchi
- Publisher
- John Wiley and Sons
- Year
- 2006
- Tongue
- English
- Weight
- 322 KB
- Volume
- 12
- Category
- Article
- ISSN
- 1075-2617
- DOI
- 10.1002/psc.740
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✦ Synopsis
Abstract
We synthesized three different lengths of poly(L‐lysine) containing an ‐SH group at the terminal (PLL~n~‐SH, n (polymerization degree) = 4, 10, 30) and adsorbed them on an Au(111) surface. To analyze the formation process and the structure of self‐assembled monolayers (SAMs), we used atomic force microscopy (AFM) and Fourier transform infrared reflection absorption spectra (FT‐IR RAS). At the initial stage of SAM growth, formation of nanosize domains was confirmed by AFM imaging. The α‐helical PLL~30~‐SH exhibited a well‐defined SAM structure after adsorption reached equilibrium. The α‐helical PLL~30~‐SH was almost perpendicular to the gold surface and exhibited interesting molecular packing due to the secondary structure of PLL~30~‐SH and the underlying Au(111) array. The tilt angle of the helix axis from the substrate normal was estimated to be about 50° (AFM) and 44° (FT‐IR RAS) respectively. On the other hand, PLL~4~‐SH and PLL~10~‐SH formed β‐sheet‐type SAMs on the Au(111) surface based on the structure determined by FT‐IR RAS spectrum. Copyright © 2005 European Peptide Society and John Wiley & Sons, Ltd.