National Center for
3F87: An alpha/beta-Peptide Helix Bundle with a Pure beta-Amino Acid Core and a Distinctive Quarternary Structure: GCN4pLI derivative with beta residues at a and d heptad positions - higher symmetry crystal
An alpha/beta-peptide helix bundle with a pure beta3-amino acid core and a distinctive quaternary structure
J. Am. Chem. Soc. (2009) 131 p.9860-9861
Helix bundles are among the most widely studied tertiary and quaternary structural motifs in proteins. Here we present the crystal structure of an alpha/beta-peptide foldamer that adopts a tetrameric helix-bundle quaternary structure with a hydrophobic core composed solely of beta-amino acids. The structure displays features that are unprecedented among all known helix bundles composed of either alpha-peptides or peptidic foldamers. The tetramer is characterized by an asymmetry of interaction between neighboring helices, and the side-chain packing within the hydrophobic core differs fundamentally from the knobs-into-holes arrangement typical of most helix bundles.