AKR1C3-IN-1

Kinase experiment:

A competitive fluorescence assay is used to measure AKR1C enzyme activity, where a nonfluorescent ketone probe (probe 5) selective for the AKR1C enzyme isoforms is reduced to a fluorescent alcohol in the presence of AKR1C enzyme and NADPH. Briefly, purified protein (2 μg/mL AKR1C1, 1 μg/mL AKR1C2, 2 μg/mL AKR1C3, and 5 μg/mL AKR1C4) are incubated with 40 μM probe 5, AKR1C3-IN-1, and 50 μM NADPH in an assay buffer of 10 mM MOPS (pH=7.2), 130 mM NaCl, 1 mM DTT, and 0.01% Triton-X-100 for 1 h at 37°C. The reaction is stopped by addition of 35 mM NaOH, and fluorescence is read in a SpectraMax M2 microplate reader at excitation/emission wavelengths of 420/510 nM. The compounds and known AKR1C3 inhibitors (flufenamic acid, indomethacin, naproxen, meclofenamic acid, S(+)-ibuprofen and flurbiprofen) are tested at multiple concentrations between 0.1 nM and 100 μM in 2% DMSO to generate AKR1C enzyme inhibition data. Compound IC50 values are calculated by fitting the inhibition data to a four-parameter logistic sigmoidal dose-response curve using Prism 5.02.

References:

[1]. Jamieson SM, et al. 3-(3,4-Dihydroisoquinolin-2(1H)-ylsulfonyl)benzoic Acids: highly potent and selective inhibitors of the type 5 17-β-hydroxysteroid dehydrogenase AKR1C3. J Med Chem. 2012 Sep 13;55(17):7746-58.