title: Effects of Ca2+ions on bestrophin-1 surface films.
abstract: Human bestrophin-1 (hBest1) is a transmembrane calcium-activated chloride channel protein - member of the bestrophin family of anion channels, predominantly expressed in the membrane of retinal pigment epithelium (RPE) cells. Mutations in the protein cause ocular diseases, named Bestrophinopathies. Here, we present the first Fourier transform infrared (FTIR) study of the secondary structure elements of hBest1, π/A isotherms and hysteresis, Brewster angle microscopy (BAM) and atomic force microscopy (AFM) visualization of the aggregation state of protein molecules dispersed as Langmuir and Langmuir-Blodgett films. The secondary structure of hBest1 consists predominantly of 310-helices (27.2%), α-helixes (16.3%), β-turns and loops (32.2%). AFM images of hBest1 suggest approximate lateral dimensions of 100×160Å and 75Å height. Binding of calcium ions (Ca2+) induces conformational changes in the protein secondary structure leading to assembly of protein molecules and changes in molecular and macro-organization of hBest1 in monolayers. These data provide basic information needed in pursuit of molecular mechanisms underlying retinal and other pathologies linked to this protein.
authors: Sofia University "St. Kliment Ohridski", Department of Biochemistry, Faculty of Biology, 8 Dragan Tzankov str., 1164 Sofia, Bulgaria.
authors: Kirilka
authors: K
authors: Mladenova
authors: Sofia University "St. Kliment Ohridski", Department of Biochemistry, Faculty of Biology, 8 Dragan Tzankov str., 1164 Sofia, Bulgaria.
authors: Svetla D
authors: SD
authors: Petrova
authors: Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, 1113 Sofia, Bulgaria.
authors: Tonya D
authors: TD
authors: Andreeva
authors: Sofia University "St. Kliment Ohridski", Department of Cytology, Histology and Embryology, Faculty of Biology, 8 Dragan Tzankov str., 1164 Sofia, Bulgaria.
authors: Veselina
authors: V
authors: Moskova-Doumanova
authors: Sofia University "St. Kliment Ohridski", Department of Cytology, Histology and Embryology, Faculty of Biology, 8 Dragan Tzankov str., 1164 Sofia, Bulgaria.
authors: Tanya
authors: T
authors: Topouzova-Hristova
authors: Institute of Mineralogy and Crystallography, Acad. G. Bonchev Str., Bl. 107, 1113 Sofia, Bulgaria.
authors: Yuri
authors: Y
authors: Kalvachev
authors: Sofia University "St. Kliment Ohridski", Department of Physical Chemistry, Faculty of Chemistry and Pharmacy, 1 James Bourchier Blvd., 1164 Sofia, Bulgaria.
authors: Konstantin
authors: K
authors: Balashev
authors: Andalusian Center of Molecular Biology and Regenerative Medicine, Centro Andaluz de Biología Molecular y Medicina Regenerativa (CABIMER), Avda. Americo Vespucio s/n, Parque Cientifico y Tecnologico, Isla de la Cartuja 41092 Sevilla, Spain.
authors: Shomi S
authors: SS
authors: Bhattacharya
authors: Institute of Ophthalmology, University College London, 11-43 Bath Street, London EC1 V 9EL, UK.
authors: Christina
authors: C
authors: Chakarova
authors: Sofia University "St. Kliment Ohridski", Department of Biochemistry, Faculty of Biology, 8 Dragan Tzankov str., 1164 Sofia, Bulgaria.
authors: Zdravko
authors: Z
authors: Lalchev
authors: Sofia University "St. Kliment Ohridski", Department of Biochemistry, Faculty of Biology, 8 Dragan Tzankov str., 1164 Sofia, Bulgaria. Electronic address: doumanov@biofac.uni-sofia.bg.
authors: Jordan A
authors: JA
authors: Doumanov
mesh_terms: D000818:Animals; D000075002:Bestrophins; D002118:Calcium / Q000737:chemistry*; D002413:Cations, Divalent; D018118:Chloride Channels / Q000737:chemistry* / Q000235:genetics; D004285:Dogs; D005136:Eye Proteins / Q000737:chemistry* / Q000235:genetics; D015870:Gene Expression; D006801:Humans; D061985:Madin Darby Canine Kidney Cells; D008567:Membranes, Artificial; D009154:Mutation; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics; D013499:Surface Properties; D013816:Thermodynamics
chemical_list: C113133:BEST1 protein, human; D000075002:Bestrophins; D002413:Cations, Divalent; D018118:Chloride Channels; D005136:Eye Proteins; D008567:Membranes, Artificial; D011994:Recombinant Proteins; D002118:Calcium
keywords: AFM; BAM; FTIR; Langmuir-Blodgett films; hBest1; π/A isotherms