A team at Exscientia, led by Martin Redhead and David Damerell, in collaboration with BioAscent, has published a paper entitled “Application of particle swarm optimisation to understand the mechanism of action of allosteric inhibitors of the enzyme HSD17β13”.  The co-publication builds on the development of a challenging assay for the enzyme HSD17β13 and subsequent high-throughput screen performed in collaboration with Exscientia.

Exscientia chose BioAscent as a partner due to our expertise in assay development and track record of successful identification of allosteric hits from previous HTS. This hit discovery expertise coupled with our extensive compound storage and handling support allowed us to rapidly receive, store, plate and screen an external 50,000 compound library, and then efficiently and quickly cherry pick and plate hits for follow up and validation.

Assay development required extensive optimisation and troubleshooting of the chosen Promega NAD(P)H Glo technology. In particular, due to components of the NAD(P)H Glo kit acting as substrates of HSD17β13, the BioAscent team needed to identify a method of stopping HSD17β13 activity without affecting the coupling enzymes. To solve this difficult problem, BioAscent used its PAINS library of known problematic compounds, to not only optimise the assay and reduce its sensitivity to undesirable hits, but to identify a compound that would stop HSD17β13 activity whilst not affecting the NAD(P)H Glo coupling system.  Once the assay was developed and its robustness demonstrated, BioAscent screened a 50k external library, followed by hit confirmation and validation, identifying hits that were further validated by the Exscientia team.

Dr Stuart McElroy, Director of Biosciences at BioAscent, commented “Throughout the assay development and screening process, BioAscent focused on rapid problem solving in collaboration with the Exscientia team, setting up bi-weekly meetings to discuss timelines, assay development, results, and troubleshooting, and worked diligently to optimize the assay.

Of course, no two assay developments and screens proceed alike, all have their unique issues.  At BioAscent we pride ourselves on working closely with our customers as integrated project team members, responding flexibly to the data as it appears during each new phase in the screen. We believe this allows us to identify the most interesting compounds to take forward for further screening”.

Dr Martin Redhead, Head of Molecular Pharmacology at Exscientia, commented “In order to power our cutting-edge AI and ML approaches to drug discovery, Exscientia requires high quality data, which can be generated through collaboration with scientific experts. BioAscent delivered assay development and screening services which identified the compound studied in our publication, which provided allosteric inhibition via an unusual mechanism.”

The full paper is published in Cell Press Patterns (Volume 4, Issue 5, 100733, May 12, 2023), and describes a Particle Swarm Optimisation technique, an unbiased method to better interrogate complex protein kinetics to help determine a drug candidate's mechanism of action.