Super-resolution microscopy reveals structural diversity in molecular exchange among peptide amphiphile nanofibres

• Published in: Nature communications Vol. 7; no. 1; pp. 11561 - 10
• Main Authors: da Silva, Ricardo M. P., van der Zwaag, Daan, Albertazzi, Lorenzo, Lee, Sungsoo S., Meijer, E. W., Stupp, Samuel I.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 19.05.2016; Nature Publishing Group; Nature Portfolio
• Subjects: 639/638/45/535; 639/638/92/56; 639/925/930/328; adhesion; biophysical chemistry; Biophysical chemistry Microscopy Structural biology; Cell division; cells; Dyes; dynamics; Extracellular matrix; GENERAL AND MISCELLANEOUS; Humanities and Social Sciences; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; MATERIALS SCIENCE; medicine; Microscopy; multidisciplinary; multivalency; Peptides; probes; Science; Science (multidisciplinary); structural biology; systems; vesicles; United States > US; Illinois; Chicago Illinois
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms11561

The dynamic behaviour of supramolecular systems is an important dimension of their potential functions. Here, we report on the use of stochastic optical reconstruction microscopy to study the molecular exchange of peptide amphiphile nanofibres, supramolecular systems known to have important biomedical functions. Solutions of nanofibres labelled with different dyes (Cy3 and Cy5) were mixed, and the distribution of dyes inserting into initially single-colour nanofibres was quantified using correlative image analysis. Our observations are consistent with an exchange mechanism involving monomers or small clusters of molecules inserting randomly into a fibre. Different exchange rates are observed within the same fibre, suggesting that local cohesive structures exist on the basis of β-sheet discontinuous domains. The results reported here show that peptide amphiphile supramolecular systems can be dynamic and that their intermolecular interactions affect exchange patterns. This information can be used to generate useful aggregate morphologies for improved biomedical function. Dynamic behaviour in supramolecular systems is an important aspect of their functionality. Here, the authors use stochastic optical reconstruction microscopy to unveil structural diversity in self-assembled peptide amphiphile nanofibres, with potential relevance to biomedical applications.