Conformation of model, alanine and proline containing tetrapeptides in water. Comparison of 13C-n.m.r. and CD results.
CD spectra of model alanine and prolyl-alanine tetrapeptides were measured at different pH values. An analysis of the spectra shows that proline in position 2 or 4 of a tetrapeptide favours folding of the peptide chain, and unfolding when it is in position 3. Changes in CD spectra evidence growing amounts of the beta-turn conformation upon increasing pH, independent of proline position in the peptide chain.
D000409:Alanine; D002942:Circular Dichroism; D009682:Magnetic Resonance Spectroscopy; D009842:Oligopeptides; D011392:Proline; D011487:Protein Conformation; D013329:Structure-Activity Relationship; D014867:Water
D009842:Oligopeptides; D014867:Water; D011392:Proline; D000409:Alanine