Figure 4. (A) Residuals obtained from fitting the fluorescent trace from a typical experiment to three, four, or five components. When four components are used, the residuals generally are no larger than the random noise, which is approximately 1% of the total increase in fluorescence observed between mixing and equilibrium. (B) Decrease in the value of the sum of the squares of the residuals as a function of the number of fluorescence components (exponentials) used in the nonlinear least-squares fit of experimental fluorescent traces. Each component is defined by an amplitude and a rate. Each point is the average plus/minus SD from nine experiments. The total amplitudes of all traces were normalized to 1.0. Final concentrations were 2.0 micro Meter Dns-C6-Cho and 0.4 micro Meter agonist binding sites.
