Kinetics of Compound Binding
In addition to enabling screening of different enzyme forms, the LanthaScreen Eu Kinase Binding Assay also has the advantage of allowing real-time measurements of compound binding, unlike activity assays. This feature can facilitate characterization of many so-called allosteric or Type II kinase inhibitors that often have a slow “on rate”, which arises when the compound binds preferentially to a conformation of the kinase that is in equilibrium with other forms. Although this can be measured by monitoring the activity of the kinase at various time points after preincubating the kinase and inhibitor, it is simpler to monitor this binding directly, as shown in Figure 5, in which the binding of BIRB-796 to p38 alpha is monitored over time.
The LanthaScreen Eu Kinase Binding Assay platform enables researchers to assay previously challenging targets, whether for inclusion in broad selectivity studies or for primary and secondary screening. Unlike traditional activity assays, this novel format allows for rapid, efficient assessment of inhibitor binding to kinases in either active or nonactive conformations, as well as kinases with activity too low to be easily studied with traditional methods.