View article

The self-assembly of nanotubes from chiral amphiphiles and peptide mimics is still poorly understood. Here, we present the first complete path to nanotubes by chiral self-assembly studied with C₁₂-β₁₂ (N-α-lauryl-lysyl-aminolauryl-lysyl-amide), a molecule designed to have unique hybrid architecture. Using the technique of direct-imaging cryo-transmission electron microscopy (cryo-TEM), we show the time-evolution from micelles of C₁₂-β₁₂ to closed nanotubes, passing through several types of one-dimensional (1-D) intermediates such as elongated fibrils, twisted ribbons, and coiled helical ribbons. Scattering and diffraction techniques confirm that the fundamental unit is a monolayer lamella of C₁₂-β₁₂, with the hydrophobic tails in the gel state and β-sheet arrangement. The lamellae are held together by a combination of hydrophobic interactions, and two sets of hydrogen-bonding networks, supporting C₁₂-β₁₂ …