Figure 2. Affinity to TSPO in [³H]PK11195 radioligand binding assay.

A. Chemical structures of EB54 and EB148. B. U87MG cell membranes (20 μg of proteins) were incubated with 1.5 nM [³H]PK11195 and different compound concentrations. After reaching equilibrium, samples were filtered and bound radioactivity was counted. Data are expressed as a percentage of specific binding versus the basal value (set to 100%) and represent the mean ± SEM of three different experiments. C. Kinetics binding profile of [³H]PK11195 to TSPO. U87MG cell membranes (20 μg protein) were incubated with 1.5 nM radioligand at various times up to 3 h. Dissociation kinetics were determined by pre-equilibrating membranes and [³H]PK11195 for 180 min; a saturating concentration of cold PK11195 (1 μM) was then added at various times. Association and dissociation data are expressed as percentage of maximum specific binding, and globally fit using Prism 5.0. Data represent the mean ± SEM of three different experiments.