IRSp53 binds to PSD-95 via PDZ/PBM interactions. (A) ITC-based measurements of interactions between the PDZ domains of PSD-95 and the full-length IRSp53. 400 μΜ of PSD-95_PDZ1, PDZ2, or PSG was titrated into 20 μM of IRSp53. 200 μΜ of PSD-95_PDZ12 was titrated into 20 μM of IRSp53. (B and C) ITC-based assay measuring the binding affinity of different PSD-95 constructs to IRSp53_ΔPBM. 200 μM PSD-95 was titrated into 20 μM IRSp53_ΔPBM.