Figure 3.

Representative lifetime decays and residual errors for W87in (top) and W167in (bottom) at 30 °C. Decays were collected at the peak emission wavelength determined from the steady-state emission spectra for each single-Trp variant. Each panel contains the instrument response function (black), the raw decay data (green), and the final fit from which lifetime data were derived (red). W87in was fit as a triexponential; W167in was fit as a biexponential. The panels showing the residuals underneath the fluorescence traces are listed in order of increasing number of exponentials. The associated χ² values for W87in are 15.29 (top), 1.44 (middle), and 1.01 (bottom) for a one, two, and three-exponential fit, respectively. For W167in, the respective χ² values were 1.90 (top) and 1.10 (bottom) for one and two exponentials.