Figure 9.
Temperature dependence of the diffusion-limited rate for contact formation. The values of kD+ measured at 10°, 20°, and 30°C for peptide agq (diamonds), age (squares), and aqe (open circles) in GdmCl and for peptide aqe in urea (solid circles) are reported as a function of the reciprocal absolute temperature. Each value of kD+ has been obtained from the viscosity dependence of the triplet quenching rate using four different sucrose concentrations. Given the relatively high photodamage of tryptophan during the triplet quenching experiments, new samples have been prepared for each temperature. The dashed lines represent Arrhenius fits. Error bars represent the uncertainties on the extracted value of ηkD+.