Stability of Nanopeptides: Structure and Molecular Exchange of Self-assembled Peptide Fibers

Nico König, Szymon Mikolaj Szostak, Josefine Eilsø Nielsen, Martha Dunbar, Su Yang, Weike Chen, Ari Benjamin, Aurel Radulescu, Najet Mahmoudi, Lutz Willner, Sinan Keten, He Dong, Reidar Lund*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

4 Scopus citations

Abstract

Often nanostructures formed by self-assembly of small molecules based on hydrophobic interactions are rather unstable, causing morphological changes or even dissolution when exposed to changes in aqueous media. In contrast, peptides offer precise control of the nanostructure through a range of molecular interactions where physical stability can be engineered in and, to a certain extent, decoupled from size via rational design. Here, we investigate a family of peptides that form beta-sheet nanofibers and demonstrate a remarkable physical stability even after attachment of poly(ethylene glycol). We employed small-angle neutron/X-ray scattering, circular dichroism spectroscopy, and molecular dynamics simulation techniques to investigate the detailed nanostructure, stability, and molecular exchange. The results for the most stable sequence did not reveal any structural alterations or unimer exchange for temperatures up to 85 °C in the biologically relevant pH range. Only under severe mechanical perturbation (i.e., tip sonication) would the fibers break up, which is reflected in a very high activation barrier for unimer exchange of ∼320 kJ/mol extracted from simulations. The results give important insight into the relation between molecular structure and stability of peptide nanostructure that is important for, e.g., biomedical applications.

Original languageEnglish (US)
Pages (from-to)12394-12408
Number of pages15
JournalACS nano
Volume17
Issue number13
DOIs
StatePublished - Jul 11 2023

Keywords

  • Peptide-assembly
  • computer simulation
  • molecular exchange
  • nanostructured peptides
  • peptide−polymer conjugates
  • small-angle scattering
  • structural stability

ASJC Scopus subject areas

  • General Engineering
  • General Physics and Astronomy
  • General Materials Science

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