Formation of Mixed Ionic Complementary Peptide Fibrils |
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| Authors: | Stephen Boothroyd Alberto Saiani Aline F Miller |
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| Institution: | 1. Manchester Interdisciplinary Biocentre & School of Chemical Engineering and Analytical Science, University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK;2. School of Materials, University of Manchester, Grosvenor Street, Manchester, M1 7HS, UK |
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| Abstract: | Summary: Two peptides (FEFEFKFK and HHHHHHFEFEFKFK) have been synthesised and their phase diagrams mapped out as a function of concentration and temperature. Both peptides formed self-supporting fibrillar hydrogels above a similar critical molar gelation concentration with a fibril diameter corresponding to the length of the fully stretched monomer. Mixing the peptides in a 9:1 ratio of FEFEFKFK to histadine functionalized FEFEFKFK in the presence of nanogold particles (binds to the histadine groups) resulted in thicker fibres suggesting that two fibrils associate together to form a fibre. TEM studies revealed that the gold particles were distributed throughout the hydrogel and adjacent to both sides of the fibrillar structures with an average distance between particles of 21 nm. It is postulated that the peptides form anti-parallel beta sheet fibrils that associate together via π-stacking interactions between the imidazole side chains of the histadine groups to form a fibre, where on average 1 in every 44 peptides is functionalized. |
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| Keywords: | electron microscopy hydrogel peptide self-assembly |
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