Design of an automated enhanced-throughput platform for functional characterization of positive allosteric modulator-induced leftward shifts in apparent agonist potency in vitro

J Lab Autom. 2012 Apr;17(2):104-15. doi: 10.1177/2211068211435301. Epub 2012 Feb 1.

Abstract

Prosecution of positive allosteric modulator (PAM) targets demands a specialized assay toolset. Many GPCR or ion channel targets are adaptable to functional assays whereby PAM efficacy can be inferred from left or rightward shifts in the concentration-response curves of orthosteric agonist. The inherent emphasis on throughput and occasional paucity of radioligands for a diverse array of allosteric modulator targets yields a need for an enhanced throughput agonist potency shift assay. Here, we describe a process by which such an assay was automated with robust, reproducible in vitro pharmacology. In direct comparison with a manual CRC shift assay, the enhanced throughput automated platform described here delivered near identical rank orders (r(2) = 0.75) at ~4-fold throughput/assay iteration. Correspondingly, average cycle time/plate decreased from 104 to 72 minutes. We also observed reductions in assay interference associated with compounds exhibiting ago-allosterism, which we attribute to preread compound incubation periods which are more precisely time-constrained under automation control. By leveraging automated laboratory technology, we have achieved meaningful throughput with no sacrifice of precision. Rather than to be target-class specific, the present process was specifically designed to serve as a platform template for a variety of cell-based functional allosteric modulation assays.

MeSH terms

  • Automation, Laboratory / methods*
  • Cytological Techniques / methods*
  • Drug Evaluation, Preclinical / methods*
  • High-Throughput Screening Assays / methods
  • Humans
  • Ion Channels / agonists*
  • Technology, Pharmaceutical / methods*

Substances

  • Ion Channels