Chemistry Reference
In-Depth Information
Figure 14.9 (a) Primary sequence of a series of multidomain peptides and (b) proposed mol-
ecular model of nanofiber packing indicating hydrophobic packing, axis of hydrogen bonding,
and repulsive charge interaction. Reprinted from Dong et al. (2007). Copyright 2007 American
Chemical Society.
thermodynamic equilibrium through the balance of forces driving self-assembly
(hydrophobic packing and hydrogen bonding) and opposing forces (electrostatic
repulsion) favoring solubility. The importance of charge interaction in determining
and controlling the fiber length has been corroborated in salt mixing experiments,
which showed that the addition of salt dramatically changed the morphology of
nanofibers from being short and dispersed to a cross-linked fiber network.
14.3.3. Nanofibers Derived from Short Peptide Sequences
There are numerous reports on the design of building blocks that adopted primarily
b-sheets from very short peptides. They can be structurally as simple as di-, tri-, and
tetra-amino acid peptides; however, mostly these short peptides were covalently
modified by organic functionality to set the conformation in favor of b-sheet
packing. For instance, Kelly's group systematically studied the self-assembly of
peptidomimetics that comprised two segments of tetrapeptides linked together by
a dibenzofuran moiety forming a b-hairpin structure (Lashuel et al. 2000;
