Relationship between salt-bridge identity and 14-helix stability of beta3-peptides in aqueous buffer.

We report a systematic analysis of the relationship between salt bridge composition and 14-helix structure within a family of model beta-peptides in aqueous buffer. We find an inverse relationship between side-chain length and the extent of 14-helix structure as judged by CD. Introduction of a stabilizing salt bridge pair within a previously reported beta-peptide ligand for hDM2 led to changes in structure that were detectable by NMR.