Dielectric assembly of a collagen-model polypeptide in a triple helix

In expectation of the formation of a thermally stable, dielectric supramolecular assembly of a polypeptide with an amino acid sequence similar to that of type-2 collagen, a sequential polypeptide consisting of the repetition of the Pro-Pro-Gly tripeptide was synthesized by solid-phase synthesis. Column chromatography of an ethanol solution of (Pro-Pro-Gly)₁₀ NH₂ showed the presence of a double helix or triple helix of the polypeptide. The pattern of a circular dichroism (CD) spectrum of an ethanol solution of (Pro-Pro-Gly)₁₀ NH₂ was very similar to that of an aqueous solution of (Pro-Pro-Gly)₁₀ OH, strongly suggesting the presence of a triple helix of the polypeptide in ethanol. An oriented monolayer assembly of (Pro-Pro-Gly)₁₀ NH₂ was formed on a thin gold film. The distribution of surface unevenness and the surface potential were investigated with Kelvin force microscopy. The rising spots carried an electric potential from room temperature to 150 °C. The correspondence showed the usefulness of the oriented monolayer of the sequential polypeptide materials for thermally stable, dielectric nanodevices. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3632–3639, 2003