Distinctive circular dichroism signature for 14-helix-bundle formation by ß-peptides

We identify a distinctive circular dichroism (CD) signature for self-assembled 14-helical ß-peptides. Our data show that self-assembly leads to a mimimum at 205 nm, which is distinct from the well-known minimum at 214 nm for a monomeric 14-helix. The onset of assembly is indicated by [θ]₂₀₅/[θ]₂₁₄ > 0.7. Our results will facilitate rapid screening for self-assembling ß-peptides and raise the possibility that far-UV CD will be useful for detecting higher-order structure for other well-folded oligoamide backbones.