Time-dependent inhibition of PHD2
Isabelle Tcholakov1, Charles E Grimshaw2, Lihong Shi2
1In Vitro Pharmacology, Immunology, Takeda California, Inc., 10410 Science Center Drive, San Diego, CA 92121, U.S.A.
Bioscience Reports
|June 9, 2017
Summary
Small molecule inhibitors targeting prolyl hydroxylases (PHDs) show promise for anemia treatment. These compounds reversibly inhibit PHDs by competing with 2-oxoglutarate, acting as pan PHD inhibitors with long-lasting effects.
Area of Science:
- Biochemistry
- Pharmacology
- Cellular Biology
Background:
- Prolyl hydroxylases (PHDs) regulate hypoxia-inducible factors (HIFs) through proline residue hydroxylation, impacting cellular response to hypoxia.
- PHD inhibitors are under investigation for anemia treatment, with several in clinical trials.
Purpose of the Study:
- To perform detailed kinetic analysis of small molecule PHD inhibitors.
- To elucidate the mechanism of inhibition for these compounds.
Main Methods:
- Enzyme kinetics assays were performed to determine inhibition constants and mechanisms.
- Analysis included determination of co-substrate competition and time-dependent inhibition (TDI).
Main Results:
- The inhibitors were found to be reversible and competitive with 2-oxoglutarate (2-OG) at the enzyme active site.
- Most compounds acted as pan PHD inhibitors, affecting multiple PHD isoforms.
- A time-dependent inhibition (TDI) mechanism was observed, characterized by a slow dissociation rate constant (koff) and long residence time.
Conclusions:
- Small molecule PHD inhibitors exhibit competitive inhibition with 2-OG.
- The observed TDI mechanism suggests prolonged target engagement, potentially beneficial for therapeutic applications.
- These findings provide valuable kinetic insights for the development of PHD inhibitors for anemia.
Keywords:
hypoxiahypoxia inducible factorliquid chromatography-tandem mass spectrometryprolyl hydroxylase 2residence timetime-dependent inhibitionMore Related Videos
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