title: Analyzing Protein-Phosphoinositide Interactions with Liposome Flotation Assays.
abstract: Liposome flotation assays are a convenient tool to study protein-phosphoinositide interactions. Working with liposomes resembles physiological conditions more than protein-lipid overlay assays, which makes this method less prone to detect false positive interactions. However, liposome lipid composition must be well-considered in order to prevent nonspecific binding of the protein through electrostatic interactions with negatively charged lipids like phosphatidylserine. In this protocol we use the PROPPIN Hsv2 (homologous with swollen vacuole phenotype 2) as an example to demonstrate the influence of liposome lipid composition on binding and show how phosphoinositide binding specificities of a protein can be characterized with this method.
authors.affiliation: Department of Neurobiology, Max-Planck-Institute for Biophysical Chemistry, Am Faßberg 11, 37077, Göttingen, Germany.
authors.forename: Ricarda A
authors.initials: RA
authors.lastname: Busse
authors.affiliation: Department of Neurobiology, Max-Planck-Institute for Biophysical Chemistry, Am Faßberg 11, 37077, Göttingen, Germany.
authors.forename: Andreea
authors.initials: A
authors.lastname: Scacioc
authors.affiliation: Department of Neurobiology, Max-Planck-Institute for Biophysical Chemistry, Am Faßberg 11, 37077, Göttingen, Germany.|Department of Biochemistry and Molecular Genetics, University of Illinois at Chicago, Chicago, IL, 60607, USA.
authors.forename: Amanda M
authors.initials: AM
authors.lastname: Schalk
authors.affiliation: Institute of Cellular Biochemistry, University Medicine, Georg-August University, Humboldtallee 23, 37073, Göttingen, Germany.
authors.forename: Roswitha
authors.initials: R
authors.lastname: Krick
authors.affiliation: Institute of Cellular Biochemistry, University Medicine, Georg-August University, Humboldtallee 23, 37073, Göttingen, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Thumm
authors.affiliation: Department of Neurobiology, Max-Planck-Institute for Biophysical Chemistry, Am Faßberg 11, 37077, Göttingen, Germany. kkuehne@gwdg.de.
authors.forename: Karin
authors.initials: K
authors.lastname: Kühnel
mesh_terms: D008081:Liposomes / Q000737:chemistry; D010716:Phosphatidylinositols / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D011506:Proteins / Q000737:chemistry / Q000378:metabolism; D055672:Static Electricity
chemical_list: D008081:Liposomes; D010716:Phosphatidylinositols; D011506:Proteins
keywords: Analytical ultracentrifuge; Hsv2; PROPPIN; Protein–lipid overlay assay; Small unilamellar vesicle s