Evaluation of Cellular Dielectric Spectroscopy, a Whole-Cell, Label-Free Technology for Drug Discovery on G_i-Coupled GPCRs

¹ Lead Generation, AstraZeneca Pharmaceuticals LP, Wilmington, DE
² Neuroscience Biology Departments, AstraZeneca Pharmaceuticals LP, Wilmington, DE

^* To whom correspondence should be addressed. E-mail: Matt.Peters{at}astrazeneca.com.

	Abstract

Cellular dielectric spectroscopy (CDS) is an emerging technology capable of detecting a range of whole-cell responses in a label-free manner. A new CDS-based instrument, CellKey, has been developed that is optimized for G-protein coupled receptor (GPCR) detection and has automated liquid handling in microplate format, thereby making CDS accessible to lead generation/optimization drug discovery. In addition to having sufficient throughput, new assay technologies must pass rigorous standards for assay development, signal window, dynamic range, and reproducibility to effectively support drug discovery SAR studies. Here, the authors evaluated CellKey with 3 different G_i-coupled GPCRs for suitability in supporting SAR studies. Optimized assay conditions compatible with the precision, reproducibility, and throughput required for routine screening were quickly achieved for each target. Across a 1000-fold range in compound potencies, CellKey results correlated with agonist and antagonist data obtained using classical methods ([³⁵S]GTPS binding and cAMP production). For partial agonists, relative efficacy measurements also correlated with GTPS data. CellKey detection of positive allosteric modulators appeared superior to GTPS methodology. Agonist and antagonist activity could be accurately quantified under conditions of low receptor expression. CellKey is a new technology platform that uses label-free detection in a homogeneous assay that is unaffected by color quenching and is easily integrated into existing microtiter-based compound testing and data analysis procedures for drug discovery.

Key Words: cellular dielectric spectroscopy, GPCR, GTPS binding

First published on February 16, 2007, doi:10.1177/1087057106298637

Journal of Biomolecular Screening 2007;12:312.

A more recent version of this article appeared on April 1, 2007


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