| Assay Method Information | |
| | Measurement of A2b Binding Affinity |
| Description: | The reported affinity of the compounds of the invention for the human A2b adenosine receptor was determined experimentally using a radioligand filtration binding assay. This assay measures the amount of binding of a tritiated proprietary A2b receptor antagonist, in the presence and absence of a compound of the invention, to membranes made from HEK293 cells recombinantly expressing the human A2b adenosine receptor (Perkin Elmer, Cat. No. ES-013-C).To perform the assay, compounds of the invention to be tested were first solubilized in 100% DMSO and further diluted in 100% DMSO to generate, typically, a 10-point titration at half-log intervals such that the final assay concentrations did not exceed 10 μM of compound or 1% DMSO. 148 μL (135 μg/mL) membranes and 2 μL test compounds were transferred to individual wells of a 96-well polypropylene assay plate and incubated for 15 to 30 minutes at room temperature with agitation. Tritiated radioligand was diluted to a concentration of 14 nM in assay buffer (phosphate buffered saline without Magnesium and Calcium, pH 7.4; GE Healthcare Life Sciences, Cat. No. SH30256.01) and then 50 μL of the solution were transferred to each well of the assay plate. To define total and non-specific binding, wells containing 1% DMSO and 20 μM N-ethylcarboxamidoadenosine (Tocris Bioscience, Cat. No. 1691) respectively, were also included. The wells of the assay plate were incubated at room temperature for 60 minutes with agitation, then filtered using a FilterMate Harvester (Perkin Elmer) or similar equipment through a UniFilter-96 PEI coated plate (Perkin Elmer Cat. No. 6005274 or 6005277). Filtering was achieved by aspirating the contents of the assay plate for 5 seconds, then washing and aspirating the contents three times with ice-cooled wash buffer (assay buffer supplemented with 0.0025% Brij58) and allowing the vacuum manifold to dry the plate for 30 seconds. The filter plate was incubated for at least 1 hour at 55° C. and allowed to dry. The bottom of the filter plate was then sealed with backing tape. 40 μL Ultima Gold (Perkin Elmer, Cat. No. 6013329) was added to each well of the filter plate and the top of the plate was sealed with TopSeal-A PLUS clear plate seal (Perkin Elmer, Cat. No. 6050185). The plates were then incubated for at least 20 minutes, and then the amount of radioactivity remaining in each well was determined using a TopCount (Perkin Elmer) scintillation counter. After normalization to total and non-specific binding, the percent effect at each compound concentration was calculated. The plot of percent effect versus the log of compound concentration was analyzed electronically using a 4-parameter logistic fit based on the Levenberg-Marquardt algorithm to generate IC50 values. |
| Affinity data for this assay | |
|---|---|
| If you find an error in this entry please send us an E-mail | |