GSK1904529A (GSK 4529) is a specific inhibitor of IGF-1R (IC50=27 nM) and IR(IC50=25 nM) .

IGF-1R:27 nM, Insulin receptor:25 nM

Kinase assays: GSK1904529A is dissolved in DMSO as stock solution at 10 mM. Baculovirus-expressed glutathione S-transferase-tagged proteins encoding the intracellular domain of IGF-1R (amino acids 957-1367) and IR (amino acids 979-1382) are used for determination of IC50. Kinases are activated by preincubating the enzyme (2.7 μM final concentration) in 50 mM HEPES (pH 7.5), 10 mM MgCl2, 0.1 mg/mL bovine serum albumin, and 2 mM ATP. GSK1904529A is diluted in DMSO and dispensed into the assay plates (100 nL/well). Kinase reactions contained (in 10 μL) 50 mM HEPES (pH 7.5), 3 mM DTT, 0.1 mg/mL bovine serum albumin, 1 mM CHAPS, 10 mM MgCl2, 10 μM ATP, 500 nM substrate peptide (biotin-aminohexylAEEEEYMMMMAKKKK-NH2; QPC), and 0.5 nM activated enzyme. Reactions are stopped after 1 hour at room temperature with 33 μM EDTA. Peptide phosphorylation is measured by time-resolved fluorescence resonance energy transfer with 7 nM streptavidin Surelight allophycocyanin and 1 nM europium-conjugated phosphotyrosine antibodies. Plates are read in a multilabel reader.

Cells are seeded in 96-well plates and incubated overnight at 37 °C, and treated with various concentrations of GSK1904529A for 72 hours. For the NIH-3T3/LISN, cells are seeded on collagen-coated 96-well tissue culture plates and allowed to adhere for 24 hours. The tissue culture medium is replaced with serum-free medium and the cells are treated with DMSO or GSK1904529A for 2 hours. IGF-I (30 ng/mL) is added and the cells are incubated at 37 °C for 72 hours. Cell proliferation is quantified using the CellTiter-Glo Luminescent Cell Viability Assay. IC50 values are determined.

GSK 4529

H2O: < 1 mg/mL (insoluble or slightly soluble)

Ethanol: < 1 mg/mL (insoluble or slightly soluble)

DMSO: 96.67 mg/mL (113.47 mM), Sonication is recommended.

10% DMSO+40% PEG300+5% Tween 80+45% Saline: 4 mg/mL (4.7 mM), Sonication is recommended.