Biomimetic Peptoid Structures for Therapeutic Applications

In order for folded helices to assemble into tertiary structures in water, they need to be amphipathic (e.g. where one hehcal face is hydrophobic and the other is hydrophilic). Because the first hehcal peptoids contained very hydrophobic chiral residues, ways to increase the water solubihty and side-chain diversity of the hehx-indudng residues were investigated [49]. It was found that a series of side chains with chiral-substituted carboxamides in place of the aromatic group could stiU favor hehx formation, while dramatically increasing water solubility. 

The well-defined helical structure associated with appropriately substituted peptoid oligomers (Section 1.6) can be employed to fashion compounds that closely mimic the stracture and function of certain bioactive peptides. There are many examples of small helical peptides ( 100 residues) whose mimicry by non-natural ohgomers could potentially yield valuable therapeutic and bioactive compounds. This section describes peptoids that have been rationaUy designed as mimics of antibacterial peptides, lung surfactant proteins, and coUagen proteins. Mimics of HIV-Tat protein, although relevant to this discussion, were described previously in this chapter (Sections 1.3.2 and 1.4.1). 

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