Solvent accessibility studies of β‐bends and application to cyclic hexapeptides

The solvent‐accessible surface areas (ASAs), of the atoms in tripeptides around the minimum‐energy conformations of the β‐bend types I, I′, II, and II′ have been computed as a first step in the systematic solvent accessibiity study of secondary structures. The side chains chosen at the two middle positions of the bend are L‐Ala, D‐Ala, and Gly. The ASAs of the hydrogen atoms are reported here and are found useful in determining the type of β‐bends in six examples of cyclic hexapeptides whose crystal structures are known. Comparison with observation showed that all the β‐bends in these cyclic hexapeptides were correctly identified by the present method. This points to a possible use of the method in identifying β‐bend types in solution.