Figure 6.

Thermal stability of ARD. (a) Shown are CD spectra of the ARD at the temperatures indicated in the inset. (b) The normalized ellipticity change at 208 nm is plotted as a function of temperature. Data are mean ± SE for n = 3 experiments (black circles). The blue circles are the data from one experiment at an attempt at refolding of the ARD by returning the temperature to 30°C and indicate an irreversible unfolding transition. The continuous curve represents a fit to a sigmoid function (slope 1.13 ± 0.14). The value of T_m from the fit is 34.2 ± 0.2°C. (c) Shown are tryptophan fluorescence spectra of the ARD at the temperatures indicated by the color scale. (d) The normalized fluorescence intensity increase for n = 3 experiments is plotted as the mean ± SE. The continuous curve represents a fit to a sigmoid function (slope 2.17 ± 0.10). The value of T_m from the fit of intensity data is 39.7 ± 0.1°C. To see this figure in color, go online.