Peptide Models

We have used peptide models to determine the characteristic rates of a-helix formation. The relaxation kinetics in response to a fast T-jump of a monomeric helical peptide (F_s peptide) and a coiled-coil helical peptide (GCN4-pl) are shown above. The monomeric F_s peptide dynamics represent the simple helix coil transition and yield a helix coil formation rate of 10⁷s^-1. In contrast, the coiled-coil dynamics are three orders of magnitude slower and represent the much slower cooperative process of forming tertiary (helix-helix) interactions.