PUBCHEM_BIOASSAY: Confirmation Assay for Inhibitors of Human Galactosidase (GALK). (Class of assay: confirmatory) [Related pubchem assays: 1868, 1379 ]
PUBCHEM_BIOASSAY: qHTS Validation Assay for Inhibitors of Human Galactosidase (GALK). (Class of assay: confirmatory) [Related pubchem assays (depositor defined):AID1868, AID2114]
Inhibition of galactosidase in human primary fibroblasts derived from GALT-deficient patients assessed as reduction in accumulation of gal-1P at 50 uM preincubated overnight prior galactose challenge measured after 4 hrs
Inhibition of galactosidase in human primary fibroblasts derived from GALT-deficient patients assessed as reduction in accumulation of gal-1P at 100 uM preincubated overnight prior galactose challenge measured after 4 hrs
qHTS Assay: Assay details and protocol: The primary assay monitored ATP depletion using Promega's KinaseGlo technology, where ATP levels are measured through luminescence generated from firefly luciferase, a bioluminescent ATP-dependent enzymes. ATP was held at 35 μM, near its reported KM value, and the KM for galactose was determined under the 1536-well assay conditions to be 50-100M (FIG. 1A). As well, the IC50 for a commercially available CD45 inhibitor (N-(9,10-dioxo-9,10-dihydrophenanthren-2-yl)pivalamide) was confirmed (previously found to inhibit GALK (FIG. 1B)). This was used as the positive control for the assay. The assay used 5 nM GALK and a 1 hr incubation time, which gave sufficient signal:background and stability for the HTS.
Inhibition of His6-tagged recombinant human GALK expressed in Escherichia coli HMS174 (DE3) incubated for 60 mins using galactose and ATP by Kinase-Glo reagent based assay
Inhibition of His6-tagged recombinant human GALK expressed in Escherichia coli HMS174 (DE3) at 5 to 15 uM incubated for 60 mins using galactose and ATP by Kinase-Glo reagent based assay
Inhibition of recombinant human GALK1 using galactose as substrate incubated for 1 hrs in the presence of ATP by Kinase-Glo reagent based luminescence assay
Inhibition of human GALK1 in GALT-deficient human fibroblast assessed as reduction in gal-1P level incubated for 2 to 4 hrs by cellular Gal-1P accumulation assay
Inhibition of human GALK1 in GALT-deficient human fibroblast assessed as reduction in gal-1P level at 3 uM incubated for 2 to 4 hrs by cellular Gal-1P accumulation assay relative to control