MGAT SPA Assay: MGAT2 enzyme was assayed using membranes isolated from Sf9 cells expressing the recombinant human MGAT2 cDNA with 2-monooleoylglycerol and [3H]-oleoyl-CoA as substrates as described by Seethala et al. [Anal. Biochem., 383(2):144-150 (Dec. 15, 2008)]. Briefly, the assays were conducted in 384-well plates in a total volume of 30 uL at 25° C. In each assay, 200 ng of recombinant human MGAT2 membrane was incubated with 10 uM of 2-monooleoylglycerol and 15 uM of [3H]-oleoyl-CoA in 100 mM potassium phosphate (pH 7.4) for 20 min with various concentrations of compounds delivered in DMSO. The assay was terminated by the addition of 20 ul of Stopping Solution (7.5 mg/ml Yttrium Oxide Polylysine beads, 3.3 mg/ml Fraction V BSA and 200 uM Mercuric chloride in 50 mM HEPES, pH 7.4). The signal was measured 1 h after quenching the reaction using LEADSEEKERSM for 5 minutes. To calculate the degree of inhibition, the zero level of enzyme activity (blank) was defined.
MGAT LCMS Assay: The MGAT enzyme reactions were performed in CORNING Falcon 96-well Polypropylene plates, in a total volume of 60 uL of 50 mM Potassium Phosphate buffer pH 7.4, containing a final concentration of 100 uM 2-oleoylglycerol, 15 uM oleoyl-Coenzyme A and 0.0013 ug/uL Human or Mouse MGAT-2 or 0.0026 ug/uL Rat recombinant MGAT-2 membranes expressed in Sf9 cells. Assay plates were run through a fully automated robotics system and shaken for 5 seconds every minute for a total 10 minutes. The reactions were then quenched with 120 uL of ice cold methanol containing 1 ug/mL 1,2-distearoyl-rac-glycerol as the internal standard. Plates were shaken for 2 minutes and spun down to remove protein precipitation. After the spin, samples were transferred to LC/MS compatible PCR plates. For LC/MS analysis, a ThermoFisher Surveyor pump, utilizing a Waters Symmetry C8, 50x2.1 mm column, was used for the chromatography of enzyme products.
Inhibition of human recombinant MGAT2 expressed in Sf9 cell membrane using 2-monooleglycerol and [H3]-oleoyl-CoA as substrates incubated for 20 mins by scintillation proximity assay
Inhibition of mouse recombinant MGAT2 expressed in Sf9 cell membrane using 2-oleoylglycerol and oleoyl-CoA as substrates incubated for 10 mins by LCMS assay
Inhibition of rat recombinant MGAT2 expressed in Sf9 cell membrane using 2-oleoylglycerol and oleoyl-CoA as substrates incubated for 10 mins by LCMS assay