Figure 5.
Comparison of protein enrichment in the different membrane subdomains. (A) Dot blot characterization of exosomal LDTI membranes. K562 and Daudi exosomes were lysed in 1% Triton X-100 and subjected to sucrose gradient centrifugation. The distribution of the 3 raft markers (GM1, Lyn, and flotillin-1) in the gradients was assessed by dot blot. Aliquots of the fractions were analyzed for HLA-DRα distribution in the gradient from Daudi exosomes. (B) Known protein amounts of exosomes, cells, and LDTI membranes isolated from cells or exosomes were loaded on SDS-PAGE to get roughly comparable amounts of flotillin and were analyzed by Western blot for the indicated proteins.