Figure 3.

A comparison of CD3ζ phosphorylation mechanisms. A model analysis for mechanisms of (A) sequential-order phosphorylation, (B) random-order phosphorylation, (C) phosphate-priming phosphorylation (Phos) rates, and (D) competitive inhibition (Inhib) by unphosphorylated and phosphorylated CD3ζ ITAM sites is shown. (Top) The model was fitted to experimental data. Error represents the residual error between the model and the data for all data sets, including wild-type, individual tyrosine-to-phenylalanine mutants, and different liposome concentrations. AIC represents the Akaike information criterion calculation for each model (AIC_i). We also report the AIC difference (Δ_i) between each model and the model with the lowest AIC, as a means of model comparison. (Middle) Half-maximal times of the model predictions are shown. (Bottom) Hill coefficients of the model predictions are shown. Black dots indicate the mean values from the sigmoidal fit to the data shown in Fig. 1, D and F. To see this figure in color, go online.