Assay Method Information

Assay Name:  HIF-PH Assay
Description:  Ketoglutaric acid α-[1-14C]-sodium salt, alpha-ketoglutaric acid sodium salt, and HPLC purified peptide were obtained from commercial sources, e.g., Perkin-Elmer (Wellesley Mass.), Sigma-Aldrich, and SynPep Corp. (Dublin Calif.), respectively. Peptides for use in the assay were fragments of HIFα as described above or as disclosed in International Publication WO 2005/118836, incorporated by reference herein. For example, a HIF peptide for use in the HIF-PH assay was [methoxycoumarin]-DLDLEALAPYIPADDDFQL-amide. HIF-PH, e.g., HIF-PH2 (also known as EGLN1 or PHD2), was expressed in, e.g., insect Hi5 cells, and partially purified, e.g., through a SP ion exchange chromatography column. Enzyme activity was determined by capturing 14CO2 using an assay described by Kivirikko and Myllyla (1982, Methods Enzymol. 82:245-304). Assay reactions contained 50 mM HEPES (pH 7.4), 100 μM α-ketoglutaric acid sodium salt, 0.30 μCi/mL α-ketoglutaric acid α-[1-14C]-sodium salt, 40 μM FeSO4, 1 mM ascorbate, 1541.8 units/mL Catalase, with or without 50 μM peptide substrate and various concentrations of compound of the invention. Reactions were initiated by addition of HIF-PH enzyme. The peptide-dependent percent turnover was calculated by subtracting percent turnover in the absence of peptide from percent turnover in the presence of substrate peptide. Percent inhibition and IC50 were calculated using peptide-dependent percent turnover at given inhibitor concentrations. Calculation of IC50 values for each inhibitor was conducted using GraFit software (Erithacus Software Ltd., Surrey UK).
Affinity data for this assay
 

If you find an error in this entry please send us an E-mail