PDHK — application of off-rate screening
Off-rate screening of unpurified reaction products by SPR drove rapid hit-to-lead progression to selective, sub-100 nM pan-isoform PDHK inhibitors.
The Challenge
Hit-to-lead progression is usually gated by compound purification: every candidate has to be cleaned up before it can be measured, which caps how much chemical space a programme can sample. Vernalis pioneered off-rate screening to remove that constraint — measuring binding kinetics directly on unpurified reaction products. PDHK, a pan-isoform target requiring broad ATP-competitive coverage, was the test case.
Related Publications
Application of Off-Rate Screening in the Identification of Novel Pan-Isoform Inhibitors of Pyruvate Dehydrogenase Kinase
Brough, P. A. et al., J. Med. Chem. 2017, 60, 2271–2286
Read on ACS PublicationsVER-246608, a Novel Pan-Isoform ATP Competitive Inhibitor of Pyruvate Dehydrogenase Kinase, Disrupts Warburg Metabolism and Induces Context-Dependent Cytostasis in Cancer Cells
Moore, J. D. et al., Oncotarget 2014, 5, 12862–12876
Read on Impact JournalsOff-Rate Screening (ORS) by Surface Plasmon Resonance. An Efficient Method to Kinetically Sample Hit to Lead Chemical Space from Unpurified Reaction Products
Murray, J. B. et al., J. Med. Chem. 2014, 57, 2845–2850
Read on ACS PublicationsThe Science
Libraries of non-purified resorcinol amide derivatives were screened by surface plasmon resonance (SPR) to determine the binding dissociation constant (off-rate) for compounds binding to the pyruvate dehydrogenase kinase (PDHK) enzyme.
Parallel off-rate measurements against Hsp90, together with the application of structure-based drug design, enabled rapid hit-to-lead progression in a programme to identify pan-isoform ATP-competitive inhibitors of PDHK.
Lead optimisation identified selective, sub-100 nM inhibitors of the enzyme, such as VER-246808, which significantly reduced phosphorylation of the E1α subunit in the PC3 cancer cell line in vitro.
Crystal structure of an inhibitor bound to PDHK (PDB: 4V26).
Key Takeaways
- Screening unpurified reaction products removes compound purification from the critical path
- Parallel off-rate measurement against Hsp90 built selectivity into the cascade, not after it
- Selective, sub-100 nM pan-isoform inhibitors identified, including VER-246808
- Cellular target engagement confirmed by reduced E1a phosphorylation in PC3 cells
Service Areas
Work with us
Vernalis has collaborated with a wide range of partners to enable some of the most challenging therapeutic targets. Present and past collaborators include Servier, Pierre Fabre, Genentech and Lundbeck. Vernalis can support programs with DEL and fragment-based technologies through to establishing full drug discovery programmes for our partners.
Our track record is built on innovation and success in enabling drug discovery and identifying clinical candidates for a wide variety of therapeutic targets.
Research Director and Joint Site Lead
James Murray PhD
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