Figure 3.

Plot of the relative fluorescence versus time for the refolding of the mutant in the presence of ANS. The refolding data are in red, whereas the fit is shown in black. The process exhibits an increase in fluorescence, followed by a biexponential decay in the fluorescence intensity. The inset shows the first 600 msec of the folding reaction. The kinetic behavior of the F42W mutant differs from that of WT IL-1β where release of ANS is noticeably faster than that previously determined for WT IL-1β (22) in the initial phase of folding (inset).