Photoaffinity labeling of a P-3 purinoceptor-like protein purified from rat brain membranes

We have found a novel adenosine binding protein in rat brain membranes. Based on the ligand binding specificities, this protein is not classified into any known P-1 or P-2 purinoceptors but is likely to be classified into the putative P3 purinoceptor which was recently proposed. This P-3 purinoceptor-like protein was partially purified from rat brain membranes and characterized further by photoaffinity labeling with 8-azidoadenosine-5'-[gamma-P-32]triphosphate. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the labeled preparations revealed that the probe is incorporated specifically into a single band with an approximate molecular size of 54kDa. (C) 1996 Academic Press, Inc.