Liposome Binding Assay to Characterize the Structure and Function of Cavin Proteins.

Protein-protein and protein-lipid interactions play important roles in the assembly of protein coats that regulate membrane organization, signaling, and trafficking in eukaryotic cells. Caveolae are plasma membrane invaginations that are formed by a protein coat consisting of caveolin and cavin protein complexes. The biochemical and structural principles of membrane binding by coat components can be studied through in vitro reconstitution of purified proteins and lipid vesicles. In this chapter, we describe a method to isolate peripheral cavin coat complexes and to subsequently bind purified cavin to chemically defined liposomes. The cavin proteoliposomes can be further analyzed to gain insights into lipid binding specificity, membrane-remodeling properties, and structural characteristics of the cavin family members.