CHEMBL5734883

Solid Phase Receptor Assay (SPRA) for alphavbeta3 Function: Recombinant human vitronectin (R& D Systems, 2308-VN) diluted to 1 μg/mL in TBS+ buffer (25 mM Tris pH 7.4, 137 mM NaCl, 2.7 mM KCl, 1 mM CaCl2, 1 mM MgCl2, 1 mM MnCl2) was added to wells (50 μL/well) of a 96-well half-well transparent microtiter plate (Greiner 675061) and incubated overnight at 4° C. Wells were washed 3 times with 150 μL TBS+ and 150 μL of blocking buffer (TBS+ with 1% bovine serum albumin, Sigma A7906) were added. The plate was incubated for 1 hr at 37° C. and then washed 3× with TBS+ buffer. Recombinant human integrin αvβ3 (R&D Systems, 3050-AV) was diluted to 1 μg/mL in TBS+/0.1% bovine serum albumin. Compounds were diluted 1:100 into the integrin solution and then 50 μL added to empty wells of the washed vitronectin-coated plate according to a standard template with each sample repeated in triplicate. After incubation for two hours at room temperature, the plate was washed 3× with 150 μL of TBS+ buffer. To each well, 50 μL of biotinylated anti-αv antibody (R&D Systems, BAF1219) at 0.5 μg/mL in TBS+/0.1% BSA were added and the plate covered and incubated for 1 hr at room temperature. After washing the plate 3× with 150 μL of TBS+ buffer, 50 μL of streptavidin-conjugated horseradish peroxidase (R&D Systems, DY998) diluted in TBS+ blocking buffer were added to the wells and the plate incubated for 20 min at room temperature. The plate was washed 3× with TBS+ buffer followed by 50 μL of TMB substrate (Sigma, T4444) added to each well and the plate was incubated for 20 min at room temperature. Plates were read by colorimetric detection at 650 nm wavelength using a Tecan Safire II plate reader. Concentration-response curves were constructed by non-linear regression (best fit) analysis, and IC50 values were calculated for each compound.