Assay Method Information

Assay Name:  In Vitro JAK Kinase Assay
Description:  JAK1 inhibitors that can be used for the treatment of cytokine-related diseases or disorders are tested for inhibitory activity of JAK targets according to the following in vitro assay described in Park et al., Analytical Biochemistry 1999, 269, 94-104. The catalytic domains of human JAK1 (a.a. 837-1142), JAK2 (a.a. 828-1132) and JAK3 (a.a. 781-1124) with an N-terminal His tag are expressed using baculovirus in insect cells and purified. The catalytic activity of JAK1, JAK2 or JAK3 was assayed by measuring the phosphorylation of a biotinylated peptide. The phosphorylated peptide was detected by homogenous time resolved fluorescence (HTRF). IC5os of compounds are measured for each kinase in the 40 microL reactions that contain the enzyme, 1 mM ATP and 500 nM peptide in 50 mM Tris (pH 7.8) buffer with 100 mM NaCl, 5 mM DTT, and 0.1 mg/mL (0.01%) BSA. For the 1 mM IC50 measurements, ATP concentration in the reactions is 1 mM. Reactions are carried out at room temperature for 1 hour and then stopped with 20 μL 45 mM EDTA, 300 nM SA-APC, 6 nM Eu-Py20 in assay buffer (Perkin Elmer, Boston, MA). Binding to the Europium labeled antibody takes place for 40 minutes and HTRF signal was measured on a Fusion plate reader (Perkin Elmer, Boston, MA).
Affinity data for this assay
 

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