CHEMBL5737269

Biochemical ATX Assay (Assay A): 5 nM recombinant ATX (Cayman Chemicals) was supplemented to 50 mM Tris buffer (pH 8.0) containing 3 mM KCl, 1 mM CaCl2, 1 mM MgCl2 0.14 mM NaCl, and 0.1% bovine serum albumin. Test compounds were dissolved in DMSO and tested in the range of 0.1 nM to 10 μM. The enzymatic reaction (22.5 μL) was started by addition of 2.5 μL 10 μM 18:1 LPC (Avanti Lipids, Alabaster, Ala., USA). After 2-h incubation at room temperature, the reaction was stopped by addition of 20 μL water containing 500 nM 20:4 LPA as internal standard and 100 μL 1-butanol for extracting LPA. Subsequently, the plates were centrifuged at 4000 rpm, 4° C., for 2 min. The resultant upper butanol phase was directly used for injection at a RapidFire system (Agilent).The RapidFire autosampler was coupled to a binary pump (Agilent 1290) and a Triple Quad 6500 (ABSciex, Toronto, Canada). This system was equipped with a 10-μL loop, 5 μL Waters Atlantis HILIC cartridge (Waters, Elstree, UK), 90% acetonitrile containing 10 mM ammonium acetate as eluent A and 40% acetonitrile containing 10 mM ammoniumacetate as eluent B. For details see (Bretschneider et al., SLAS Discovery, 2017). 1 The MS was operated in negative mode with a source temperature of 550° C., curtain gas=35, gas 1=65, and gas 2=80. The following transitions and MS parameters (DP: declustering potential and CE: collision energy) for the respective LPAs were determined: 18:1 LPA at 435.2/152.8, DP=−40, CE=−28 and 20:4 LPA at 457.2/152.8, DP=−100, CE=−27).