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Updated: Jul 7, 2026

Split-and-pool Synthesis and Characterization of Peptide Tertiary Amide Library
Published on: June 20, 2014
Aggregation of the amphipathic peptides (AAKA)n into antiparallel beta-sheets
Thomas J Measey1, Reinhard Schweitzer-Stenner
1Department of Chemistry, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104, USA.
Abstract:
Helical wheel projections of peptides based on the repeating unit Ac-(AAKA)n-NH2 clearly illustrate an amphipathic nature. One should therefore expect these peptides to form helices if the number of residues exceeds a certain threshold value. Indeed, ECD measurements show that Ac-(AAKA)4-NH2 and, to a minor extent, also Ac-(AAKA)3-NH2 exhibit some helical content at millimolar concentrations in aqueous solution. Surprisingly, however, these peptides were found to form hydrogels with an antiparallel beta-sheet conformation at centimolar concentrations. This occurs despite the positively charged lysine side chain which would be expected to inhibit the formation of extended beta-sheet layers.
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