SpeedScreen, a Label-Free, Affinity-Based High-Throughput Screening Technology for the Discovery of Orphan Protein Ligands

Abstract

A high-throughput screening method, tailored to the discovery of ligands for both known and orphan proteins, was developed and implemented into Novartis' lead discovery process. Neither labeling of target proteins nor labeling of screening compounds is required, as the ligands are affinity-selected by incubation of the protein with mixtures of compounds in aqueous binding buffer. Unbound small molecular weight compounds are removed from the target protein:ligand complex by rapid size-exclusion chromatography in 96-well plate format. The protein fraction is then analyzed subsequently by liquid chromatography/mass spectrometry (LC/MS) for identification of the bound ligand(s). All sample handling steps and the analytics are rapid, robust, and largely automated, adopting this technology to the needs of present high-throughput screening (HTS) processes. This affinity-selection technology, termed SpeedScreen, is currently an integral part of our lead discovery process. In addition to the screening of conventional compound libraries this technology can also be applied for the de-convolution of libraries originating from combinatorial chemistry efforts as well as complex natural extracts.