Comparison of the binding of α-helical and β-sheet peptides to a hydrophobic surface

The induction and stabilisation of secondary structure for a series of amphipathic α-helical and β-sheet peptides upon their binding to lipid- like surfaces has been characterised by reversed phase high-performance liquid chromatography (RP-HPLC). In addition, a series of peptides which have been shown to switch from β-sheet to α-helical conformation upon transfer from a polar to a non-polar solution environment also have been studied. Binding parameters related to the hydrophobic contact area and affinity for immobilised C18 chains were determined at temperatures that ranged from 5 to 85°C, allowing conformational transitions for the peptides during surface adsorption to be monitored. The results demonstrated that all peptides which adopt secondary structure in solution also exhibited large changes in their interactive properties. Overall, this study demonstrates that the hydrophobic face of each amphipathic peptide dominates the binding process and that hydrophobic interactions are a major factor controlling the surface induction of secondary structure.