Simultaneous Multiple MS Binding Assays Addressing D1 and D2 Dopamine Receptors

5 years ago

Simultaneous Multiple MS Binding Assays Addressing D1 and D2 Dopamine Receptors

Klaus T. Wanner, Georg Höfner, Marion Schuller

MS Binding Assays are a label-free alternative to radioligand binding assays. They provide basically the same capabilities as the latter, but use a non-labeled reporter ligand instead of a radioligand. In contrast to radioligand binding assays, MS Binding Assays offer—owing to the selectivity of mass spectrometric detection—the opportunity to monitor the binding of different reporter ligands at different targets simultaneously. The present study shows a proof of concept for this strategy as exemplified for MS Binding Assays selectively addressing D1 and D2 dopamine receptors in a single binding experiment. A highly sensitive, rapid and robust LC–ESI-MS/MS quantification method capable of quantifying both SCH23390 and raclopride, selectively addressing D1 and D2 receptors, respectively, was established and validated for this purpose. Based thereon, simultaneous saturation and competition experiments with SCH23390 and raclopride in the presence of both D1 and D2 receptors were performed and analyzed by LC–MS/MS within a single chromatographic cycle. The present study thus demonstrates the feasibility of this strategy and the high versatility of MS Binding Assays that appears to surpass that common for conventional radioligand binding assays. Beyond radiolabeling: Simultaneous Multiple MS Binding Assays provide the capability to address different targets with selective reporter ligands in a single binding experiment. This study shows the feasibility of this concept exemplified for binding experiments targeting D1 and D2 dopamine receptors using SCH23390 and raclopride as reporter ligands, quantified with high sensitivity by LC–ESI-MS/MS.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/cmdc.201700369