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Direct observation of morphological transformation from twisted ribbons into helical ribbons.

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.

SUBMITTER: Pashuck ET

PROVIDER: S-EPMC3116515 | biostudies-literature | 2010 Jul

REPOSITORIES: biostudies-literature

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Direct observation of morphological transformation from twisted ribbons into helical ribbons.

Pashuck E Thomas ET Stupp Samuel I SI

Journal of the American Chemical Society 20100701 26

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 molec ...[more]

PMID: 20552966

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