Peptide Self-Assembly Measured Using Fluorescence Correlation Spectroscopy
Fluorescence correlation spectroscopy (FCS) is a flexible and powerful technique to measure the diffusion of fluorescently labeled particles. It has been important in examining a range of biological processes, from intracellular transport, to DNA hybridization. It is particularly suited to measuring the assembly of peptides, since peptides are often too small to be detected by standard light scattering methods, or may not contain aromatic amino acid residues, which limits the use of other spectroscopic techniques. In this protocol, we describe state-of-the-art sample preparation for Aβ1–42 peptide solutions and the measurement and analysis of the self-assembly of the peptide to form fibrils via a number of intermediate states using FCS.
Key wordsFluorescence correlation spectroscopy Peptide Self-assembly Size distribution Complex fluids Polydispersity Gaussian distribution model
This work was made possible by funding from Science Foundation Ireland Stokes Lectureship (to J. J.McM); European Science Foundation networking programme “epitopeMap” (grant to J.O. R. and J. J. McM); EU FP7 (NanoTransKinetics grant to JJM, JOR), Deutsche Forschungsgemeinschaft (JJM, travel grant).
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