Table 2.

Summary of determined affinities and trypsin digestion results

Affinities of differently phosphorylated peptides to arrestin-1, -2 and -3 (see Fig. 2) are listed on the left side of the table, and the summary of limited trypsin digest results for arrestin-1, -2 and -3 (see Fig. 3 and Supplementary Figure 1) is listed on the right side of the table. All affinity measurements were performed in triplicate. The determined dissociation constants (K_d) are listed. The K_d values of noninteracting or weakly interacting phosphopeptides that could not be determined because they were below the detectable range of the assay are indicated as “>250”. Phosphopeptides that induced a change in the digest pattern of arrestin-1 and arrestin-3 from three to two bands are indicated by “+”, and those that failed to induce a change are indicated by “−”. In our hands, trypsin digestion of arrestin-2 always resulted in two bands, and the presence of certain phosphopeptides increased the rate of digestion. Increased rate of digestion is indicated by “Faster”, and no change in rate is indicated by “Normal” (Source data are provided as a Source Data file.)