Can ionic effects induce α-sheet conformation of Peptides?

We report coupled cluster, MP2 and DFT data on the relative energy and geometry of alpha-sheet and 13-strand conformations of model peptides. We show that ionic effects have a strong effect on energy balance through formation of multiple cation-oxygen contacts in the alpha-sheet form. Such effects are markedly dependent on both sequence and ion: two peptides considered favour alpha-sheet in the presence of cations, whereas a third, non-polar one favours 13-strand in the same conditions.

Automated summary

Ionic effects play a significant role in the energy balance of peptide conformations, primarily through the formation of multiple cation-oxygen contacts in the alpha-sheet form. This effect is highly dependent on the sequence of peptides and the type of ions present, with some peptides favoring alpha-sheet while others favor 13-strand under the same conditions.