Self-assembly of the peptide A10K – Intermediate state in aggregate formation
July 31-August 4, 2017
We have studied the synthetic surfactant-like peptide A10K in solution. Upon mixing the freeze dried, essentially amorphous peptide powder in heavy water, the peptides self-assemble into long ribbon-like aggregates with a fixed cross section of circa 3x8 nm. It is still unclear whether this self-assembly is equilibrium like a surfactant micelle formation or whether it corresponds to a precipitation of a solid phase. Through light scattering measurements on dilution series, the solubility of the ribbons has been determined to 4.7 μM. However, quantitative NMR spectroscopy shows a monomer concentration of 3 mM, corresponding to a roughly 60 times supersaturation, and independent of the total concentration. Samples prepared directly at, or below this specific concentration shows no, or only minor signs of aggregation. In combination with a broad peak in high resolution 1H NMR spectroscopy we conclude that the formation of the A10K aggregates occurs through an intermediate state in equilibrium with the peptide monomers.
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Axel Rüter, Stefan Kuczera, Luigi Gentile, Karl-Erik Bergquist, and Ulf Olsson, "Self-assembly of the peptide A10K – Intermediate state in aggregate formation" in "Association in Solution IV", Ulf Olsson, Lund University, Sweden Norman Wagner, University of Delaware, USA Anand Yethiraj, Memorial University of Newfoundland, Canada Eds, ECI Symposium Series, (2017). http://dc.engconfintl.org/assoc_solution_iv/6