Purification of membrane receptors with peptide-carrying affinity latex particles

We developed affinity particles and a purification method for specific proteins using batchwise operation. In this study, affinity particles carrying Gly-Arg-Gly-Asp-Ser peptides were employed for the purification of receptor proteins from octylglucoside extracts of human platelets. The molecular masses of the purified proteins were 116 118 kD or 90 133 kD as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis under reducing or non-reducing conditions, respectively. The affinity between the peptides on the particles and these proteins depended on peptide sequences, divalent cations, and temperature. Western blotting with monoclonal anti-human platelet GP IIIa antibody indicated that the proteins were GP IIb/IIIa. Thus, it was concluded that efficient and quick purification is feasible using the affinity particles.