a. Helical wheel of GCN4-pAA (left) and 7-helix bundle with
helices A-G represented by the different colors. Coiled-coil lock washer is
represented by the displaced edge of the structure occurs at the interface
between the first (A, blue) and the seventh (G, gray) helices. b.
Helical wheel of the sequence of peptide 7HSAP1(left) and schematic
representation of the proposed model for self-assembly of lock-washer structures
derived from the 7-helix bundle of peptide 7HSAP1 into helical nanotubes.
c. The 7-helix bundle of GCN4-pAA that occupies structural
homologous positions with respect to the isotopically labeled sites in 7HSAP1*:
carbonyl carbons (C’) of Ala9 (black), amide nitrogen of Leu13 (blue),
and methyl carbons of Ala21 (gray). Reproduced with permission from Ref.
[74] Copyright 2013,
American Chemical Society