Figure 2.

Immunoblot demonstrating immunoaffinity isolation of thromboxane receptors: (Left) Western blot demonstrating isolation of TXA₂ receptors from human platelet lysates. TXA₂ receptors were isolated by incubating platelet lysates with TXR2 anti-receptor antibody precoupled to agarose beads. Bead eluates (E1–E3) were resolved by SDS/PAGE, transferred to nitrocellulose, and then immunoblotted with TXR2 antibody. L, platelet lysate; L*, lysate after incubating with TXR2 antibody beads; B*, IgG from TXR2 beads; E1–E3, sequential eluates from the TXR2 antibody beads incubated with platelet lysate, washed, and then eluted with low pH glycine buffer. The 47–53-kDa band in lanes L, E1, E2, and E3 is the platelet TXA₂ receptor. (Right) Separate experiments demonstrating the expected (ref. 42) small decrease in M_r of the TXA₂ receptor following endoproteinase Lys-C digestion. One of four similar experiments. R, TXA₂ receptors; LC, receptor digested with endoproteinase Lys-C.