Fig. 6
Engineering PSD-95 selective ligands. a Design of selective competitors against PSD-95 tandem PDZ domains. The purple ball corresponds to the Xph clone C-terminus (T94) that is fused to the linker and binding motif. The binding motif can in principle bind to each domain (overlay of the two situations). b Representative SPR sensorgrams obtained by single-cycle kinetics of tandem PDZ domains (analyte) against immobilized biotinylated Xph15/18/20-binding motif (ligand). The reported concentrations represent the highest concentration used on the final analyte injection, the previous four injections are a series of twofold dilutions. The coloured curves represent measured data points and black lines represent the global fit obtained with a 1:1 binding model used for analysis. For rate plane with isoaffinity diagonals representation, see Supplementary Fig. 24. c Competitive titrations of Xph20-ETWV against a complex of tandem PDZ domains and a divalent ligand. Top: colloidal blue-stained SDS-PAGE analysis of the competition against indicated PDZ domains (non-competed material). Bottom: quantification by densitometry of competition. Each data point represents the mean of two independent experiments and s.e.m. For uncropped gels, see Supplementary Fig. 25. Source data are provided as Source Data file
