BCSJ : Vol. 80 (2007) , No. 8 pp.1483-1491

Unique Helical Triangle Molecular Geometry Induced by Dipole–Dipole Interactions

Takahito Ishikawa¹⁾, Tomoyuki Morita¹⁾ and Shunsaku Kimura¹⁾

1) Department of Material Chemistry, Graduate School of Engineering, Kyoto University

(Received January 22, 2007)

Novel helix-peptide wheels, in which three helices were connected by using a template, were prepared, and the dipole–dipole interactions among the helices were studied in relation to the formation of a planar triangle structure containing three helices. The helical segments had a 3₁₀-helix structure. ¹³C spin-lattice relaxation time (T₁) measurements showed that the helical segments had restricted mobility. Deuterium exchange rates of amide protons were accelerated in the helix-peptide wheels compared to the respective linear helix peptides, suggesting that there is torsion on the cylindrical shape. Therefore, the predominant structure of the helix-peptide wheels is a planar triangle in solution. Further, the triangle structure was successfully transferred onto a gold substrate.

Novel helix-peptide wheels, in which three helices were connected by using a template, were prepared, and dipole–dipole interactions among helices were studied in relation to the formation of a planar triangle structure involving three helices.