Fig 4.
Example NMR spectra of PDZ domain titrated with compounds in the intermediate or in the fast exchange regime. (a) NMR spectra of PDZ domain titrated with compound 1, which is in intermediate exchange with the PDZ domain with a low-micromolar binding affinity. Spectra are colored by the protein to ligand ratios: red (1:0), blue (1:0.72), green (1:3.6), cyan (1:7.2), orange (1:10.8) and magenta (1:14.4). (b) NMR spectra of PDZ domain titrated with compound 15, which is in fast exchange with the PDZ domain with a relative weak binding affinity. Spectra are colored by the protein to ligand ratios: red (1:0), blue (1:1), green (1:6), cyan (1:10) and orange (1:15).