Liposome-Binding Assays to Assess Specificity and Affinity of PhospholipidProtein Interactions

Protein–lipid interactions play an important role in cellular protein relocation, activation and signal transduction. The liposome-binding assay is a simple and inexpensive method to examine protein–lipid binding in vitro. The phospholipids used for liposome production are dried and hydrated. Subsequent extrusion of the phospholipid mixture ensures the production of large unilamellar vesicles (LUV) filled with raffinose. Those LUVs can be easily separated from the aqueous solution by centrifugation. By incubating a protein of interest with the LUVs and subsequent centrifugation steps, the bound protein fraction can be determined using Western Blot or Coomassie staining. This technique enables analysis of protein–lipid binding affinity and specificity.