CHEMBL3705907

Enzyme Assay: MIF tautomerase activity was measured by UV-Visible recording spectrophotometry (SHIMADZU, UV1600U). A fresh stock solution of L-dopachrome methyl ester was prepared at 2.4 mM through oxidation of L-3,4-dihydroxyphenylalanine methyl ester with sodium periodate. 1 μL of MIF solution (800-900 ng/mL) and 1 μL of a DMSO solution with various concentrations of the enzymatic inhibitor were added into a plastic cuvette (10 mm, 1.5 mL) containing 0.7 mL assay buffer (50 mM potassium phosphate, pH 7.2). Then L-dopachrome methyl ester solution (0.3 mL) was added to the assay buffer mixture. Activity was determined at room temperature and the spectrometric measurements were made at λ=475 nm for 20 seconds by monitoring the rate of decolorization of L-dopachrome methyl ester in comparison to a standard solution.