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Updated: Jun 12, 2026

Scalable Nanohelices for Predictive Studies and Enhanced 3D Visualization
Published on: November 12, 2014
Direct observation of morphological transformation from twisted ribbons into helical ribbons
E Thomas Pashuck1, Samuel I Stupp
1Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, USA.
Abstract:
We report on the direct observation of a nanostructural transformation from a twisted ribbon to a helical ribbon in supramolecular assemblies of peptide amphiphiles. Using cryogenic electron microscopy, a peptide amphiphile molecule containing aromatic residues was found to first assemble into short twisted ribbons in the time range of seconds, which then elongate in the time scale of minutes, and finally transform into helical ribbons over the course of weeks. By synthesizing an analogous molecule without the aromatic side groups, it was found that a cylindrical nanostructure is formed that does not undergo any transitions during the same time period. The study of metastable states in peptide aggregation can contribute to our understanding of amyloid-related diseases, such as Alzheimer's disease.
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