and bound ligands. A common way to measure the T1 value of a small molecule is the inversion recovery experiment [158,159], although other experiments are also available such as ultrafast NMR T1 [160] and saturation inversion recovery [161]. In general, the shorter T1 the relaxation time the less intense the peak signal will be and the broader the signal linewidth [162]. The T1 values of free and bound ligand will