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Nerath G, Oliveira DA, Siqueira JR, Caseli L. Using Carbon Nanotubes to Improve Enzyme Activity and Electroactivity of Fatty Acid Langmuir-Blodgett Film-Incorporated Galactose Oxidase for Sensing and Energy Storage Applications. ACS APPLIED MATERIALS & INTERFACES 2024. [PMID: 38334123 DOI: 10.1021/acsami.3c18824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2024]
Abstract
Incorporating enzymes into nanostructured supercapacitor devices represents a groundbreaking advancement in energy storage. Enzyme catalysis using nanomaterials enhances performance, efficiency, and stability by facilitating precise charge transfer, while the nanostructure provides a high surface area and improved conductivity. This synergy yields eco-friendly, high-performance energy storage solutions crucial for diverse applications, from portable electronics to renewable energy systems. In this study, we harnessed the versatility of Langmuir-Blodgett films to create meticulously organized thin films with specific enzyme properties, coupled with carbon nanotubes, to develop biosupercapacitors. Langmuir monolayers were constructed with stearic acid, carbon nanotubes, and galactose oxidase. Following comprehensive characterization using tensiometric, rheological, morphological, and spectroscopic techniques, the monolayers were transferred to solid supports, yielding Langmuir-Blodgett films. These films exhibited superior performance, with persisting enzyme activity. However, increasing film thickness did not enhance enzymatic activity values, indicating a surface-driven process. Subsequently, we explored the electrochemical properties of the films, revealing stability compatible with supercapacitor applications. The introduction of carbon nanotubes demonstrated a higher capacitance, indicating the potential viability of the films for energy storage applications.
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Affiliation(s)
- Gabriel Nerath
- Laboratory of Hybrid Materials (LMH), Institute of Environmental, Chemical and Pharmaceutical Sciences, Federal University of São Paulo (UNIFESP), Diadema 09913-030, São Paulo, Brazil
| | - Danilo A Oliveira
- Laboratory of Applied Nanomaterials and Nanostructures (LANNA), Institute of Exact Sciences, Natural and Education, Federal University of Triângulo Mineiro (UFTM), Uberaba 38064-200, Minas Gerais, Brazil
| | - José R Siqueira
- Laboratory of Applied Nanomaterials and Nanostructures (LANNA), Institute of Exact Sciences, Natural and Education, Federal University of Triângulo Mineiro (UFTM), Uberaba 38064-200, Minas Gerais, Brazil
| | - Luciano Caseli
- Laboratory of Hybrid Materials (LMH), Institute of Environmental, Chemical and Pharmaceutical Sciences, Federal University of São Paulo (UNIFESP), Diadema 09913-030, São Paulo, Brazil
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Wadeesirisak K, Castano S, Vaysse L, Bonfils F, Peruch F, Rattanaporn K, Liengprayoon S, Lecomte S, Bottier C. Interactions of REF1 and SRPP1 rubber particle proteins from Hevea brasiliensis with synthetic phospholipids: Effect of charge and size of lipid headgroup. Biochem Biophys Res Commun 2023; 679:205-214. [PMID: 37708579 DOI: 10.1016/j.bbrc.2023.08.062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 08/18/2023] [Accepted: 08/29/2023] [Indexed: 09/16/2023]
Abstract
According to the fatty acid and headgroup compositions of the phospholipids (PL) from Hevea brasiliensis latex, three synthetic PL were selected (i.e. POPA: 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphate POPC: 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine and POPG: 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol) to investigate the effect of PL headgroup on the interactions with two major proteins of Hevea latex, i.e. Rubber Elongation Factor (REF1) and Small Rubber Particle Protein (SRPP1). Protein/lipid interactions were screened using two models (lipid vesicles in solution or lipid monolayers at air/liquid interface). Calcein leakage, surface pressure, ellipsometry, microscopy and spectroscopy revealed that both REF1 and SRPP1 displayed stronger interactions with anionic POPA and POPG, as compared to zwitterionic POPC. A particular behavior of REF1 was observed when interacting with POPA monolayers (i.e. aggregation + modification of secondary structure from α-helices to β-sheets, characteristic of its amyloid aggregated form), which might be involved in the irreversible coagulation mechanism of Hevea rubber particles.
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Affiliation(s)
- Kanthida Wadeesirisak
- Institute of Food Research and Product Development, Kasetsart University, 10900, Bangkok, Thailand
| | - Sabine Castano
- Univ. Bordeaux, CNRS, Bordeaux INP, CBMN, UMR5248, F-33600, Pessac, France
| | - Laurent Vaysse
- CIRAD, UPR BioWooEB, F-34398, Montpellier, France; BioWooEB, Univ Montpellier, CIRAD, Montpellier, France
| | - Frédéric Bonfils
- CIRAD, UPR BioWooEB, F-34398, Montpellier, France; BioWooEB, Univ Montpellier, CIRAD, Montpellier, France
| | - Frédéric Peruch
- Univ. Bordeaux, CNRS, Bordeaux INP, LCPO, UMR 5629, F-33600, Pessac, France
| | - Kittipong Rattanaporn
- Department of Biotechnology, Faculty of Agro-Industry, Kasetsart University, 10900, Bangkok, Thailand
| | - Siriluck Liengprayoon
- Kasetsart Agricultural and Agro-Industrial Product Improvement Institute, Kasetsart University, 10900, Bangkok, Thailand
| | - Sophie Lecomte
- Univ. Bordeaux, CNRS, Bordeaux INP, CBMN, UMR5248, F-33600, Pessac, France.
| | - Céline Bottier
- CIRAD, UPR BioWooEB, F-34398, Montpellier, France; BioWooEB, Univ Montpellier, CIRAD, Montpellier, France.
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Geng Y, Cao Y, Li Y, Zhao Q, Liu D, Fan G, Tian S. A Deeper Insight into the Interfacial Behavior and Structural Properties of Mixed DPPC/POPC Monolayers: Implications for Respiratory Health. MEMBRANES 2022; 13:33. [PMID: 36676840 PMCID: PMC9864691 DOI: 10.3390/membranes13010033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 12/21/2022] [Accepted: 12/26/2022] [Indexed: 06/17/2023]
Abstract
1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and 1-palmitoyl-2-oleyl-sn-glycerol-3-phosphorcholine (POPC) are important components in pulmonary surfactants (PSs), of which the relative content is related to lung compliance. Herein, the phase behavior and thermodynamic structure of mixed DPPC/POPC monolayers were studied to elucidate the intermolecular interaction between DPPC and POPC molecules. Surface pressure-molecular area isotherms demonstrated that POPC significantly affected the phase behavior of the lipid domain structure as a function of its concentration. The compression modulus of the mixed monolayers reduced with the increase in POPC proportion, which can be attributed to the intermolecular repulsion between DPPC and POPC. Brewster angle microscopy analysis showed that the ordered structure of the monolayers trended toward fluidization in the presence of POPC. Raman spectroscopy results revealed that the change in C-C skeleton stretching vibration was the main cause of the decrease in the monolayer packing density. These findings provide new insights into the role of different phospholipid components in the function of PS film at a molecular level, which can help us to understand the synergy effects of the proportional relationship between DPPC and POPC on the formation and progression of lung disease and provide some references for the synthesis of lung surfactants.
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Affiliation(s)
- Yingxue Geng
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China
- Faculty of Civil and Hydraulic Engineering, Xichang University, Xichang 615013, China
| | - Yan Cao
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China
| | - Yingjie Li
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China
| | - Qun Zhao
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China
| | - Dan Liu
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China
| | - Ge Fan
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China
| | - Senlin Tian
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650500, China
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Kalinova R, Mladenova K, Petrova S, Doumanov J, Dimitrov I. Nanoarchitectonics of Spherical Nucleic Acids with Biodegradable Polymer Cores: Synthesis and Evaluation. MATERIALS (BASEL, SWITZERLAND) 2022; 15:8917. [PMID: 36556721 PMCID: PMC9786340 DOI: 10.3390/ma15248917] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 12/09/2022] [Accepted: 12/12/2022] [Indexed: 06/17/2023]
Abstract
Spherical nucleic acids (SNAs) have gained significant attention due to their unique properties allowing them to overcome the challenges that face current nanocarriers used for gene therapies. The aim of this study is to synthesize and characterize polymer-oligonucleotide conjugates of different architecture and to evaluate the possibility of forming SNAs with biodegradable cores. Initially, two types of azide (multi)functional polyester-based (co)polymers were successfully synthesized and characterized. In the next step, short oligonucleotide strands were attached to the polymer chains applying the highly efficient and metal-free "click" reaction, thus forming conjugates with block or graft architecture. Both conjugates spontaneously self-assembled in aqueous media forming nanosized SNAs with a biodegradable polyester core and a surface of oligonucleotide chains as evidenced from dynamic and electrophoretic light scattering measurements. The nano-assemblies were in vitro evaluated for potential cytotoxicity. Furthermore, the interactions of the newly synthesized SNAs with membrane lipids were studied. The preliminary results indicate that both types of polymer-based SNAs are good candidates for potential application in gene therapy and that it is worth to be further evaluated.
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Affiliation(s)
- Radostina Kalinova
- Institute of Polymers, Bulgarian Academy of Sciences, Akad. G. Bonchev St., bl. 103-A, 1113 Sofia, Bulgaria
| | - Kirilka Mladenova
- Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tzankov Blvd., 1164 Sofia, Bulgaria
| | - Svetla Petrova
- Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tzankov Blvd., 1164 Sofia, Bulgaria
| | - Jordan Doumanov
- Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tzankov Blvd., 1164 Sofia, Bulgaria
| | - Ivaylo Dimitrov
- Institute of Polymers, Bulgarian Academy of Sciences, Akad. G. Bonchev St., bl. 103-A, 1113 Sofia, Bulgaria
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Videv P, Mladenova K, Andreeva TD, Park JH, Moskova-Doumanova V, Petrova SD, Doumanov JA. Cholesterol Alters the Phase Separation in Model Membranes Containing hBest1. Molecules 2022; 27:molecules27134267. [PMID: 35807512 PMCID: PMC9268032 DOI: 10.3390/molecules27134267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Revised: 06/24/2022] [Accepted: 06/29/2022] [Indexed: 02/04/2023] Open
Abstract
Human retinal pigment epithelial (RPE) cells express the transmembrane Ca2+-dependent Cl− channel bestrophin-1 (hBest1) of the plasma membrane. Mutations in the hBest1 protein are associated with the development of distinct pathological conditions known as bestrophinopathies. The interactions between hBest1 and plasma membrane lipids (cholesterol (Chol), 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and sphingomyelin (SM)) determine its lateral organization and surface dynamics, i.e., their miscibility or phase separation. Using the surface pressure/mean molecular area (π/A) isotherms, hysteresis and compressibility moduli (Cs−1) of hBest1/POPC/Chol and hBest1/SM/Chol composite Langmuir monolayers, we established that the films are in an LE (liquid-expanded) or LE-LC (liquid-condensed) state, the components are well-mixed and the Ca2+ ions have a condensing effect on the surface molecular organization. Cholesterol causes a decrease in the elasticity of both films and a decrease in the ΔGmixπ values (reduction of phase separation) of hBest1/POPC/Chol films. For the hBest1/SM/Chol monolayers, the negative values of ΔGmixπ are retained and equalized with the values of ΔGmixπ in the hBest1/POPC/Chol films. Shifts in phase separation/miscibility by cholesterol can lead to changes in the structure and localization of hBest1 in the lipid rafts and its channel functions.
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Affiliation(s)
- Pavel Videv
- Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tzankov Str., 1164 Sofia, Bulgaria; (P.V.); (K.M.); (J.H.P.); (V.M.-D.); (S.D.P.)
| | - Kirilka Mladenova
- Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tzankov Str., 1164 Sofia, Bulgaria; (P.V.); (K.M.); (J.H.P.); (V.M.-D.); (S.D.P.)
| | - Tonya D. Andreeva
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, 1113 Sofia, Bulgaria;
- Faculty of Applied Chemistry, Reutlingen University, Alteburgstraße 150, 72762 Reutlingen, Germany
| | - Jong Hun Park
- Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tzankov Str., 1164 Sofia, Bulgaria; (P.V.); (K.M.); (J.H.P.); (V.M.-D.); (S.D.P.)
| | - Veselina Moskova-Doumanova
- Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tzankov Str., 1164 Sofia, Bulgaria; (P.V.); (K.M.); (J.H.P.); (V.M.-D.); (S.D.P.)
| | - Svetla D. Petrova
- Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tzankov Str., 1164 Sofia, Bulgaria; (P.V.); (K.M.); (J.H.P.); (V.M.-D.); (S.D.P.)
| | - Jordan A. Doumanov
- Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tzankov Str., 1164 Sofia, Bulgaria; (P.V.); (K.M.); (J.H.P.); (V.M.-D.); (S.D.P.)
- Correspondence: ; Tel.: +359-2-8167-262; Fax: +359-2-8656-641
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Self-organization and surface properties of hBest1 in models of biological membranes. Adv Colloid Interface Sci 2022; 302:102619. [PMID: 35276535 DOI: 10.1016/j.cis.2022.102619] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 02/19/2022] [Accepted: 02/20/2022] [Indexed: 11/22/2022]
Abstract
The transmembrane Ca2+ - activated Cl- channel - human bestrophin-1 (hBest1) is expressed in retinal pigment epithelium and mutations of BEST1 gene cause ocular degenerative diseases colectivelly referred to as "bestrophinopathies". A large number of genetical, biochemical, biophysical and molecular biological studies have been performed to understand the relationship between structure and function of the hBest1 protein and its pathophysiological significance. Here, we review the current understanding of hBest1 surface organization, interactions with membrane lipids in model membranes, and its association with microdomains of cellular membranes. These highlights are significant for modulation of channel activity in cells.
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Videv P, Mladenov N, Andreeva T, Mladenova K, Moskova-Doumanova V, Nikolaev G, Petrova SD, Doumanov JA. Condensing Effect of Cholesterol on hBest1/POPC and hBest1/SM Langmuir Monolayers. MEMBRANES 2021; 11:membranes11010052. [PMID: 33451008 PMCID: PMC7828479 DOI: 10.3390/membranes11010052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Revised: 01/10/2021] [Accepted: 01/12/2021] [Indexed: 11/22/2022]
Abstract
Human bestrophin-1 protein (hBest1) is a transmembrane channel associated with the calcium-dependent transport of chloride ions in the retinal pigment epithelium as well as with the transport of glutamate and GABA in nerve cells. Interactions between hBest1, sphingomyelins, phosphatidylcholines and cholesterol are crucial for hBest1 association with cell membrane domains and its biological functions. As cholesterol plays a key role in the formation of lipid rafts, motional ordering of lipids and modeling/remodeling of the lateral membrane structure, we examined the effect of different cholesterol concentrations on the surface tension of hBest1/POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine) and hBest1/SM Langmuir monolayers in the presence/absence of Ca2+ ions using surface pressure measurements and Brewster angle microscopy studies. Here, we report that cholesterol: (1) has negligible condensing effect on pure hBest1 monolayers detected mainly in the presence of Ca2+ ions, and; (2) induces a condensing effect on composite hBest1/POPC and hBest1/SM monolayers. These results offer evidence for the significance of intermolecular protein–lipid interactions for the conformational dynamics of hBest1 and its biological functions as multimeric ion channel.
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Affiliation(s)
- Pavel Videv
- Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tzankov Blvd., 1164 Sofia, Bulgaria; (P.V.); (N.M.); (K.M.); (V.M.-D.); (G.N.); (S.D.P.)
| | - Nikola Mladenov
- Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tzankov Blvd., 1164 Sofia, Bulgaria; (P.V.); (N.M.); (K.M.); (V.M.-D.); (G.N.); (S.D.P.)
- Faculty of Medicine, Medical University-Sofia, 1 Sv. Georgi Sofiiski Str., 1431 Sofia, Bulgaria
| | - Tonya Andreeva
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, 1113 Sofia, Bulgaria;
- Faculty of Applied Chemistry, Reutlingen University, Alteburgstraße 150, 72762 Reutlingen, Germany
| | - Kirilka Mladenova
- Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tzankov Blvd., 1164 Sofia, Bulgaria; (P.V.); (N.M.); (K.M.); (V.M.-D.); (G.N.); (S.D.P.)
| | - Veselina Moskova-Doumanova
- Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tzankov Blvd., 1164 Sofia, Bulgaria; (P.V.); (N.M.); (K.M.); (V.M.-D.); (G.N.); (S.D.P.)
| | - Georgi Nikolaev
- Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tzankov Blvd., 1164 Sofia, Bulgaria; (P.V.); (N.M.); (K.M.); (V.M.-D.); (G.N.); (S.D.P.)
| | - Svetla D. Petrova
- Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tzankov Blvd., 1164 Sofia, Bulgaria; (P.V.); (N.M.); (K.M.); (V.M.-D.); (G.N.); (S.D.P.)
| | - Jordan A. Doumanov
- Faculty of Biology, Sofia University “St. Kliment Ohridski”, 8 Dragan Tzankov Blvd., 1164 Sofia, Bulgaria; (P.V.); (N.M.); (K.M.); (V.M.-D.); (G.N.); (S.D.P.)
- Correspondence: ; Tel.: +359-2-8167262
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Miscibility of hBest1 and sphingomyelin in surface films - A prerequisite for interaction with membrane domains. Colloids Surf B Biointerfaces 2020; 189:110893. [PMID: 32113084 DOI: 10.1016/j.colsurfb.2020.110893] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 02/08/2020] [Accepted: 02/20/2020] [Indexed: 01/07/2023]
Abstract
Human bestrophin-1 (hBest1) is a transmembrane Ca2+- dependent anion channel, associated with the transport of Cl-, HCO3- ions, γ-aminobutiric acid (GABA), glutamate (Glu), and regulation of retinal homeostasis. Its mutant forms cause retinal degenerative diseases, defined as Bestrophinopathies. Using both physicochemical - surface pressure/mean molecular area (π/A) isotherms, hysteresis, compressibility moduli of hBest1/sphingomyelin (SM) monolayers, Brewster angle microscopy (BAM) studies, and biological approaches - detergent membrane fractionation, Laurdan (6-dodecanoyl-N,N-dimethyl-2-naphthylamine) and immunofluorescence staining of stably transfected MDCK-hBest1 and MDCK II cells, we report: 1) Ca2+, Glu and GABA interact with binary hBest1/SM monolayers at 35 °C, resulting in changes in hBest1 surface conformation, structure, self-organization and surface dynamics. The process of mixing in hBest1/SM monolayers is spontaneous and the effect of protein on binary films was defined as "fluidizing", hindering the phase-transition of monolayer from liquid-expanded to intermediate (LE-M) state; 2) in stably transfected MDCK-hBest1 cells, bestrophin-1 was distributed between detergent resistant (DRM) and detergent-soluble membranes (DSM) - up to 30 % and 70 %, respectively; in alive cells, hBest1 was visualized in both liquid-ordered (Lo) and liquid-disordered (Ld) fractions, quantifying protein association up to 35 % and 65 % with Lo and Ld. Our results indicate that the spontaneous miscibility of hBest1 and SM is a prerequisite to diverse protein interactions with membrane domains, different structural conformations and biological functions.
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Effects of Ca2+, Glu and GABA on hBest1 and composite hBest1/POPC surface films. Colloids Surf B Biointerfaces 2018; 161:192-199. [DOI: 10.1016/j.colsurfb.2017.10.051] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2017] [Revised: 10/11/2017] [Accepted: 10/17/2017] [Indexed: 12/22/2022]
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Effects of Ca 2+ ions on bestrophin-1 surface films. Colloids Surf B Biointerfaces 2016; 149:226-232. [PMID: 27768912 DOI: 10.1016/j.colsurfb.2016.10.023] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 10/07/2016] [Accepted: 10/12/2016] [Indexed: 01/01/2023]
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.
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