FIG. 5.

Immunoblot of K562 cell fractions shows that proteins recognized by K5.M MAbs are in lipid rafts. Nonionic detergent lysates were prepared from K562 cells and subjected to equilibrium centrifugation on sucrose gradients, and fractions were collected as described in Materials and Methods. The fractions were subjected to immunoblot analysis with the MAbs indicated. Lipid raft and soluble fractions were identified by anti-CD59 and anti-CD71 MAbs, respectively. Anti-MHC-1 MAb (MHM.5) served as a negative control.