GSK-3ɑ (Human)
0.65 nM
CHO-IR cells expressing human insulin receptor are grown to 80% con?uence in Hamm’s F12 medium with 10% fetal bovine serum and without hypoxanthine. Trypsinized cells are seeded in 6-well plates at 1 × 106 cells/well in 2 mL of medium without fetal bovine serum. After 24 hours, medium is replaced with 1 mL of serum-free medium containing GSK-3 inhibitor CHIR 98014 or control (?nal DMSO concentration 0.1%) for 30 min at 37 °C. Cells are lysed by freeze/thaw in 50 mM tris (pH 7.8) containing 1 mM EDTA, 1 mM DTT, 100 mM NaF, 1 mM phenylmethylsulfonyl ?uoride, and 25 μg/mL leupeptin (buffer A) and centrifuged 15 min at 4 °C/14000 g. The activity ratio of GS is calculated as the GS activity in the absence of glucose-6-phosphate divided by the activity in the presence of 5 mM glucose-6-phosphate.