title: Application of Peak Intensity Analysis to Measurements of Protein Binding to Lipid Vesicles and Erythrocytes Using Fluorescence Correlation Spectroscopy: Dependence on Particle Size.
abstract: Fluorescence correlation spectroscopy (FCS) is a sensitive analytical tool for investigation of processes accompanied by changes in the mobility of molecules and complexes. In the present work, peak intensity analysis (PIA) in combination with the solution stirring using FCS setup was applied to explore the interaction between fluorescently labeled protein ligands and corresponding receptors located on membranes. In the system composed of biotinylated liposomes and fluorescently labeled streptavidin as a ligand, PIA allowed us to determine the optimum receptor concentration and demonstrate the essential dependence of the binding efficacy on the length of the linker between the biotin group and the polar head group of the lipid. The binding was dependent on the size of liposomes which was varied by lipid extrusion through filters of different pore diameters. The sensitivity of the method was higher with the liposomes of larger sizes. The PIA approach can be applied not only to liposomes but also to relatively large objects, e.g., erythrocytes or Sepharose beads derivatized with lactose as a receptor for the binding of viscumin and ricin.
authors.affiliation: Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia, 119991. antonen@genebee.msu.ru.
authors.forename: Yuri N
authors.initials: YN
authors.lastname: Antonenko
authors.affiliation: Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia, 119991.
authors.forename: Anna S
authors.initials: AS
authors.lastname: Lapashina
authors.affiliation: Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia, 119991.
authors.forename: Elena A
authors.initials: EA
authors.lastname: Kotova
authors.affiliation: Biological Department, Lomonosov Moscow State University, Moscow, Russia.
authors.forename: Alla A
authors.initials: AA
authors.lastname: Ramonova
authors.affiliation: Biological Department, Lomonosov Moscow State University, Moscow, Russia.
authors.forename: Mikhail M
authors.initials: MM
authors.lastname: Moisenovich
authors.affiliation: Biological Department, Lomonosov Moscow State University, Moscow, Russia.|Shumakov Research Center of Transplantology and Artificial Organs, Moscow, Russia.
authors.forename: Igor I
authors.initials: II
authors.lastname: Agapov
mesh_terms: D000818:Animals; D001710:Biotin; D002417:Cattle; D004912:Erythrocytes / Q000378:metabolism*; D008055:Lipids / Q000737:chemistry*; D008081:Liposomes / Q000737:chemistry; D010316:Particle Size; D011485:Protein Binding; D011506:Proteins / Q000737:chemistry* / Q000378:metabolism; D054790:Ribosome Inactivating Proteins, Type 2 / Q000737:chemistry / Q000378:metabolism; D012276:Ricin / Q000737:chemistry / Q000378:metabolism; D013050:Spectrometry, Fluorescence; D013194:Staining and Labeling; D014118:Toxins, Biological / Q000737:chemistry / Q000378:metabolism
chemical_list: D008055:Lipids; D008081:Liposomes; D011506:Proteins; D054790:Ribosome Inactivating Proteins, Type 2; D014118:Toxins, Biological; C488862:mistletoe lectin I; D001710:Biotin; D012276:Ricin
keywords: Fluorescence correlation spectroscopy (FCS); GM1; Liposome; Ricin; Streptavidin; Viscumin