title: Interaction of the water-soluble protein aprotinin with liposomes: gel-filtration, turbidity studies, and 31P NMR studies.
abstract: The interactions of a water-soluble nonmembrane protein aprotinin with multilamellar vesicles (MLV) and small unilamellar vesicles (SUV) from soybean phospholipids were studied using Sephadex G-75 gel chromatography combined with different methods of the analysis of the eluate fractions (fluorescence, light-scattering, turbidity; 31P NMR spectroscopy). The composition of the liposomes mainly containing soybean phosphatidylcholine (PC) was varied by the addition of phosphatidylethanolamine (PE), phosphatidylinositol (PI) and lyso-phosphatidylcholine (lyso-PC). To evaluate the lipid-protein interactions, the amount of aprotinin in the MLV-aprotinin complexes was determined. Lipid-protein interactions were found to strongly depend on the liposome composition, medium pH and ionic strength. These dependencies point to the electrostatic nature of the aprotinin-lipid interactions. 31P NMR spectroscopy of the MLV-aprotinin complexes indicated that aprotinin influences the phospholipid structure in MLV at pH 3.0. In the case of PC:PE:PI and PC:PE:PI:lyso-PC vesicles, aprotinin induced liposome aggregation and a lamellar-to-isotropic phase transition of the phospholipids.
authors.affiliation: Department of Chemical Enzymology, Faculty of Chemistry, Lomonosov Moscow State University, Moscow, Russia.
authors.forename: O
authors.initials: O
authors.lastname: Tiourina
authors.forename: T
authors.initials: T
authors.lastname: Sharf
authors.forename: A
authors.initials: A
authors.lastname: Balkina
authors.forename: M
authors.initials: M
authors.lastname: Ollivon
authors.forename: A
authors.initials: A
authors.lastname: Selischeva
authors.forename: G
authors.initials: G
authors.lastname: Sorokoumova
authors.forename: N
authors.initials: N
authors.lastname: Larionova
mesh_terms: D007611:Aprotinin / Q000737:chemistry / Q000378:metabolism*; D002850:Chromatography, Gel; D006863:Hydrogen-Ion Concentration; D050356:Lipid Metabolism; D008055:Lipids / Q000737:chemistry; D008081:Liposomes / Q000737:chemistry / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D009391:Nephelometry and Turbidimetry / Q000379:methods*; D010713:Phosphatidylcholines / Q000737:chemistry; D010714:Phosphatidylethanolamines / Q000737:chemistry; D010716:Phosphatidylinositols / Q000737:chemistry; D010743:Phospholipids / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D012965:Sodium Chloride / Q000737:chemistry; D012995:Solubility; D013025:Glycine max / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D008055:Lipids; D008081:Liposomes; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D010716:Phosphatidylinositols; D010743:Phospholipids; D014867:Water; D012965:Sodium Chloride; D007611:Aprotinin