CHEMBL5730108

In Vitro Enzyme Assay: A fusion protein comprising glutathione S transferase (GST) and human IRE-1α (GST-IRE-1α) was obtained from a 500 ml baculovirus-infected insect cell culture and used to measure IRE-1α activity in vitro. Five μl of a reaction mixture comprising 1× reaction buffer (5× reaction buffer is 100 mM Hepes pH 7.5, 250 mM KOAc, 2.5 mM MgCl2), 3 mM DTT, and 0.4% polyethylene glycol water were added to each well of 384 well plates. Twenty-five nanoliters of a 1 mM test compound solution were added to test wells. Three μl of a 128 ng/ml IRE-1α preparation were added to each test well and to positive control wells (final concentration 5.82 ng/well). Negative control wells contained only reaction mixture and test compound.After spinning the plates at 1200 rpm for 30 seconds, 3 μl of an IRE-1α human mini-XBP-1 mRNA stem-loop substrate 5′-CAGUCCGCAGCACUG-3′ (SEQ ID NO:1), labeled with the fluorescent dye Cy5 at the 5′ end and Black Hole Quench