Figure 1. Probing a β-arrestin 2 peptide array with PDE4D5–GST and PDE4D3–GST.

β-Arrestin 2 is shown schematically with its N- and C-domains. Results show immobilized peptide ‘spots’ of overlapping 25-mer peptides each shifted along by five amino acids in the entire β-arrestin 2 sequence probed for interaction with either PDE4D5–GST or PDE4D3–GST and detection by immunoblotting. Positively interacting peptides generate dark spots, while those that do not interact leave white (blank) spots. In all other sections of the array, spots were blank with either probe. Spot numbers relate to peptides in the scanned array and whose sequence is given as indicated. Arrays probed with purified GST did not yield any positively interacting spots. These data are typical of experiments performed three times.