Self-complementary alternating amphiphilic

Figure 20.10. Amphiphilic ionic self-complementary peptides. This class of peptides has 16 amino acids, c. 5 nm in size, with an alternating polar and non-polar pattern. They form stable (3-strand and 3-sheet structures thus, the side chains partition into two sides, one polar and the other non-polar. They undergo self-assembly to form nanofibers with the non-polar residues inside positively and negatively charged residues form complementary ionic interactions, like a checkerboard. These nanofibers form interwoven matrices that further form a scaffold hydrogel with a very high water content ( 99.5%). The simplest peptide scaffold may form compartments to separate molecules into localized places where they can not only have high concentration, but also form a molecular gradient, one of the key prerequisites for prebiotic molecular evolution.

Figure 6.3 Self-assembled nanostructures based on P-sheet (a) peptides packing into sheets and fibers based on hydrophobic interactions on one face of the molecule, and complementary ionic interaction on the other (b) peptides with alternating hydrophilic and hydrophobic residues assemble into P-sheet structures (left) that form twisted ribbons (right) and bundle into larger fibers and (c) self-assembly based on amphiphilic triblock peptides, where the central hydrophobic block forces self-assembly via hydrophobic interactions between molecules and hydrogen bonding along the fiber axis.

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