1
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Martynyuk VA, Efimova SS, Malykhina AI, Ostroumova OS. The effects of plant flavones on the membrane boundary potential and lipid packing stress. Colloids Surf B Biointerfaces 2024; 245:114269. [PMID: 39341052 DOI: 10.1016/j.colsurfb.2024.114269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2024] [Revised: 08/12/2024] [Accepted: 09/17/2024] [Indexed: 09/30/2024]
Abstract
Here we have revealed the effects of different plant flavones on the physicochemical properties of model lipid membranes. We have demonstrated that baicalein increases the boundary potential of membranes composed of phosphatidylcholine, while wogonin does not affect it. Other flavones tested reduce membrane boundary potential, with this ability increasing among scutellarein, chrysin, apigenin, morin, fisetin, and luteolin. Molecular dynamics simulations demonstrate connection of alteration in boundary potential with the preferential orientation of intrinsic flavone dipole moments in membranes. We have also shown that flavones reduce the melting point of phosphatidylcholine, and this ability increases in the series of luteolin, morin, wogonin, scutellarein, apigenin, baicalein, chrysin, and fisetin. The introduction of baicalein, chrysin and fisetin also leads to a significant decrease in the sharpness of the lipid phase transition. We have hypothesized that the localization of flavones in the glycerol backbone or in the C1-C8 methylene region of lipid hydrocarbon chains leads to an increase in the area per lipid and, as a consequence, to an expansion of the lipid melting peak. Replacement of neutral phosphatidylcholine with negatively charged phosphatidylserine affects the membrane-modifying activity of flavones which given the externalization of phosphatidylserine on the surface of cancer cells may be crucial in the flavone anticancer effects.
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Affiliation(s)
- Vera A Martynyuk
- Institute of Cytology of Russian Academy of Sciences, ikhoretsky 4, Saint Petersburg 194064, Russian Federation
| | - Svetlana S Efimova
- Institute of Cytology of Russian Academy of Sciences, ikhoretsky 4, Saint Petersburg 194064, Russian Federation
| | - Anna I Malykhina
- Institute of Cytology of Russian Academy of Sciences, ikhoretsky 4, Saint Petersburg 194064, Russian Federation
| | - Olga S Ostroumova
- Institute of Cytology of Russian Academy of Sciences, ikhoretsky 4, Saint Petersburg 194064, Russian Federation.
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2
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Kirsanov R, Khailova LS, Rokitskaya TI, Lyamzaev KG, Panteleeva AA, Nazarov PA, Firsov AM, Iaubasarova IR, Korshunova GA, Kotova EA, Antonenko YN. Synthesis of Triphenylphosphonium-Linked Derivative of 3,5-Di tert-butyl-4-hydroxybenzylidene-malononitrile (SF6847) via Knoevenagel Reaction Yields an Effective Mitochondria-Targeted Protonophoric Uncoupler. ACS OMEGA 2024; 9:11551-11561. [PMID: 38496966 PMCID: PMC10938414 DOI: 10.1021/acsomega.3c08621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 02/07/2024] [Accepted: 02/14/2024] [Indexed: 03/19/2024]
Abstract
Mitochondrial uncouplers are actively sought as potential therapeutics. Here, we report the first successful synthesis of mitochondria-targeted derivatives of the highly potent uncoupler 3,5-ditert-butyl-4-hydroxybenzylidene-malononitrile (SF6847), bearing a cationic alkyl(triphenyl)phosphonium (TPP) group. As a key step of the synthesis, we used condensation of a ketophenol with malononitrile via the Knoevenagel reaction. SF-C5-TPP with a pentamethylene linker between SF6847 and TPP, stimulating respiration and collapsing membrane potential of rat liver mitochondria at submicromolar concentrations, proved to be the most effective uncoupler of the series. SF-C5-TPP showed pronounced protonophoric activity on a model planar bilayer lipid membrane. Importantly, SF-C5-TPP exhibited rather low toxicity in fibroblast cell culture, causing mitochondrial depolarization in cells at concentrations that only slightly affected cell viability. SF-C5-TPP was more effective in decreasing the mitochondrial membrane potential in the cell culture than SF6847, in contrast to the case of isolated mitochondria. Like other zwitterionic uncouplers, SF-C5-TPP inhibited the growth of Bacillus subtilis in the micromolar concentration range.
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Affiliation(s)
- Roman
S. Kirsanov
- Belozersky
Institute of Physico-Chemical Biology, Lomonosov
Moscow State University, 119991 Moscow, Russia
| | - Ljudmila S. Khailova
- Belozersky
Institute of Physico-Chemical Biology, Lomonosov
Moscow State University, 119991 Moscow, Russia
| | - Tatyana I. Rokitskaya
- Belozersky
Institute of Physico-Chemical Biology, Lomonosov
Moscow State University, 119991 Moscow, Russia
| | - Konstantin G. Lyamzaev
- Belozersky
Institute of Physico-Chemical Biology, Lomonosov
Moscow State University, 119991 Moscow, Russia
- The
“Russian Clinical Research Center for Gerontology” of
the Ministry of Healthcare of the Russian Federation, Pirogov Russian National Research Medical University, 117997 Moscow, Russia
| | - Alisa A. Panteleeva
- Belozersky
Institute of Physico-Chemical Biology, Lomonosov
Moscow State University, 119991 Moscow, Russia
| | - Pavel A. Nazarov
- Belozersky
Institute of Physico-Chemical Biology, Lomonosov
Moscow State University, 119991 Moscow, Russia
| | - Alexander M. Firsov
- Belozersky
Institute of Physico-Chemical Biology, Lomonosov
Moscow State University, 119991 Moscow, Russia
| | - Iliuza R. Iaubasarova
- Belozersky
Institute of Physico-Chemical Biology, Lomonosov
Moscow State University, 119991 Moscow, Russia
| | - Galina A. Korshunova
- Belozersky
Institute of Physico-Chemical Biology, Lomonosov
Moscow State University, 119991 Moscow, Russia
| | - Elena A. Kotova
- Belozersky
Institute of Physico-Chemical Biology, Lomonosov
Moscow State University, 119991 Moscow, Russia
| | - Yuri N. Antonenko
- Belozersky
Institute of Physico-Chemical Biology, Lomonosov
Moscow State University, 119991 Moscow, Russia
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3
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Efimova SS, Ostroumova OS. Modulation of the Dipole Potential of Model Lipid Membranes with Phytochemicals: Molecular Mechanisms, Structure-Activity Relationships, and Implications in Reconstituted Ion Channels. MEMBRANES 2023; 13:453. [PMID: 37103880 PMCID: PMC10141572 DOI: 10.3390/membranes13040453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 04/17/2023] [Accepted: 04/18/2023] [Indexed: 06/19/2023]
Abstract
Phytochemicals, such as flavonoids, stilbenoids, alkaloids, terpenoids, and related compounds, have a wide range of useful pharmacological properties which cannot be ascribed to binding to a single peptide or protein target alone. Due to the relatively high lipophilicity of phytochemicals, the lipid membrane is thought to mediate their effects via changes in the properties of the lipid matrix, in particular, by modulating the transmembrane distribution of the electrical potential and, consequently, the formation and functioning of the ion channels reconstituted in the lipid bilayers. Therefore, biophysical studies on the interactions between plant metabolites and model lipid membranes are still of interest. This review represents an attempt to provide a critical analysis of a variety of studies on altering membranes and ion channels with phytochemicals via disturbing the potential drop at the membrane-aqueous solution interface. Critical structural motifs and functioning groups in the molecules of plant polyphenols (alkaloids and saponins are identified) and the possible mechanisms of dipole potential modulation with phytochemicals are discussed.
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Affiliation(s)
| | - Olga S. Ostroumova
- Laboratory of Membrane and Ion Channel Modeling, Institute of Cytology of Russian Academy of Science, Tikhoretsky Ave. 4, 194064 St. Petersburg, Russia
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4
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Kirsanov RS, Khailova LS, Rokitskaya TI, Iaubasarova IR, Nazarov PA, Panteleeva AA, Lyamzaev KG, Popova LB, Korshunova GA, Kotova EA, Antonenko YN. Ester-stabilized phosphorus ylides as protonophores on bilayer lipid membranes, mitochondria and chloroplasts. Bioelectrochemistry 2023; 150:108369. [PMID: 36638678 DOI: 10.1016/j.bioelechem.2023.108369] [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: 10/12/2022] [Revised: 12/19/2022] [Accepted: 01/03/2023] [Indexed: 01/06/2023]
Abstract
Triphenylphosphonium ylides are commonly used as key intermediates in the Wittig reaction. Based on the known acidities of stabilized ylide precursors, we proposed that a methylene group adjacent to phosphorus in these compounds can ensure proton shuttling across lipid membranes. Here, we synthesized (decyloxycarbonylmethyl)triphenylphosphonium bromide (CMTPP-C10) by reaction of triphenylphosphine with decyl bromoacetate. This phosphonium salt precursor of the ester-stabilized phosphorus ylide along with its octyl (CMTPP-C8) and dodecyl (CMTPP-C12) analogues was found to be a carrier of protons in mitochondrial, chloroplast and artificial lipid membranes, suggesting that it can reversibly release hydrogen ions and diffuse through the membranes in both zwitterionic (ylide) and cationic forms. The CMTPP-C10-mediated electrical current across planar bilayer lipid membranes exhibited pronounced proton selectivity. Similar to conventional protonophores, known to uncouple electron transport and ATP synthesis, CMTPP-Cn (n = 8, 10, 12) stimulated mitochondrial respiration, while decreasing membrane potential, at micromolar concentrations, thereby showing the classical uncoupling activity in mitochondria. CMTPP-C12 also caused dissipation of transmembrane pH gradient on chloroplast membranes. Importantly, CMTPP-C10 exhibited substantially lower toxicity in cell culture, than C12TPP. Thus, we report the finding of a new class of ylide-type protonophores, which is of substantial interest due to promising therapeutic properties of uncouplers.
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Affiliation(s)
- Roman S Kirsanov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Ljudmila S Khailova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Tatyana I Rokitskaya
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Iliuza R Iaubasarova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia; Faculty of Chemistry, Lomonosov Moscow State University, Leninskie Gory 1/3, Moscow 119991, Russia
| | - Pavel A Nazarov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Alisa A Panteleeva
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Konstantin G Lyamzaev
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia; The "Russian Clinical Research Center for Gerontology" of the Ministry of Healthcare of the Russian Federation, Pirogov Russian National Research Medical University, Moscow, Russia
| | - Lyudmila B Popova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Galina A Korshunova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Elena A Kotova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Yuri N Antonenko
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia.
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5
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Lipid Microenvironment Modulates the Pore-Forming Ability of Polymyxin B. Antibiotics (Basel) 2022; 11:antibiotics11101445. [PMID: 36290103 PMCID: PMC9598075 DOI: 10.3390/antibiotics11101445] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 10/18/2022] [Accepted: 10/19/2022] [Indexed: 11/17/2022] Open
Abstract
The ability of polymyxin B, an antibiotic used to treat infections caused by multidrug-resistant Gram-negative bacteria as a last-line therapeutic option, to form ion pores in model membranes composed of various phospholipids and lipopolysaccharides was studied. Our data demonstrate that polymyxin B predominantly interacts with negatively charged lipids. Susceptibility decreases as follows: Kdo2-Lipid A >> DOPG ≈ DOPS >> DPhPG ≈ TOCL ≈ Lipid A. The dimer and hexamer of polymyxin B are involved in the pore formation in DOPG(DOPS)- and Kdo2-Lipid A-enriched bilayers, respectively. The pore-forming ability of polymyxin B significantly depends on the shape of membrane lipids, which indicates that the antibiotic produces toroidal lipopeptide-lipid pores. Small amphiphilic molecules diminishing the membrane dipole potential and inducing positive curvature stress were shown to be agonists of pore formation by polymyxin B and might be used to develop innovative lipopeptide-based formulations.
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6
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Ion permeation across the membrane: A comprehensive comparison analysis on passive permeations of differently charged ions. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.119339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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7
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Disalvo A, Frias MA. Surface Characterization of Lipid Biomimetic Systems. MEMBRANES 2021; 11:membranes11110821. [PMID: 34832050 PMCID: PMC8621788 DOI: 10.3390/membranes11110821] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 10/21/2021] [Accepted: 10/21/2021] [Indexed: 11/16/2022]
Abstract
Zeta potential and dipole potential measures are direct operational methodologies to determine the adsorption, insertion and penetration of ions, amphipathic and neutral compounds into the membranes of cells and model systems. From these results, the contribution of charged and dipole groups can be deduced. However, although each method may give apparent affinity or binding constants, care should be taken to interpret them in terms of physical meaning because they are not independent properties. On the base of a recent model in which the lipid bilayer is considered as composed by two interphase regions at each side of the hydrocarbon core, this review describes how dipole potential and zeta potential are correlated due to water reorganization. From this analysis, considering that in a cell the interphase region the membrane extends to the cell interior or overlaps with the interphase region of another supramolecular structure, the correlation of dipole and electrostatic forces can be taken as responsible of the propagation of perturbations between membrane and cytoplasm and vice versa. Thus, this picture gives the membrane a responsive character in addition to that of a selective permeability barrier when integrated to a complex system.
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8
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Iaubasarova IR, Khailova LS, Firsov AM, Grivennikova VG, Kirsanov RS, Korshunova GA, Kotova EA, Antonenko YN. The mitochondria-targeted derivative of the classical uncoupler of oxidative phosphorylation carbonyl cyanide m-chlorophenylhydrazone is an effective mitochondrial recoupler. PLoS One 2020; 15:e0244499. [PMID: 33378414 PMCID: PMC7773232 DOI: 10.1371/journal.pone.0244499] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Accepted: 12/10/2020] [Indexed: 12/11/2022] Open
Abstract
The synthesis of a mitochondria-targeted derivative of the classical mitochondrial uncoupler carbonyl cyanide-m-chlorophenylhydrazone (CCCP) by alkoxy substitution of CCCP with n-decyl(triphenyl)phosphonium cation yielded mitoCCCP, which was able to inhibit the uncoupling action of CCCP, tyrphostin A9 and niclosamide on rat liver mitochondria, but not that of 2,4-dinitrophenol, at a concentration of 1–2 μM. MitoCCCP did not uncouple mitochondria by itself at these concentrations, although it exhibited uncoupling action at tens of micromolar concentrations. Thus, mitoCCCP appeared to be a more effective mitochondrial recoupler than 6-ketocholestanol. Both mitoCCCP and 6-ketocholestanol did not inhibit the protonophoric activity of CCCP in artificial bilayer lipid membranes, which might compromise the simple proton-shuttling mechanism of the uncoupling activity on mitochondria.
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Affiliation(s)
- Iliuza R. Iaubasarova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
- Faculty of Chemistry, Lomonosov Moscow State University, Moscow, Russia
| | - Ljudmila S. Khailova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Alexander M. Firsov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | | | - Roman S. Kirsanov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Galina A. Korshunova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Elena A. Kotova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Yuri N. Antonenko
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
- * E-mail:
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9
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Rokitskaya TI, Kotova EA, Luzhkov VB, Kirsanov RS, Aleksandrova EV, Korshunova GA, Tashlitsky VN, Antonenko YN. Lipophilic ion aromaticity is not important for permeability across lipid membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1863:183483. [PMID: 33002452 DOI: 10.1016/j.bbamem.2020.183483] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Revised: 08/31/2020] [Accepted: 09/22/2020] [Indexed: 12/23/2022]
Abstract
To clarify the contribution of charge delocalization in a lipophilic ion to the efficacy of its permeation through a lipid membrane, we compared the behavior of alkyl derivatives of triphenylphosphonium, tricyclohexylphosphonium and trihexylphosphonium both in natural and artificial membranes. Exploring accumulation of the lipophilic cations in response to inside-negative membrane potential generation in mitochondria by using an ion-selective electrode revealed similar mitochondrial uptake of butyltricyclohexylphosphonium (C4TCHP) and butyltriphenylphosphonium (C4TPP). Fluorescence correlation spectroscopy also demonstrated similar membrane potential-dependent accumulation of fluorescein derivatives of tricyclohexyldecylphosphonium and decyltriphenylphosphonium in mitochondria. The rate constant of lipophilic cation translocation across the bilayer lipid membrane (BLM), measured by the current relaxation method, moderately increased in the following sequence: trihexyltetradecylphosphonium ([P6,6,6,14]) < triphenyltetradecylphosphonium (C14TPP) < tricyclohexyldodecylphosphonium (C12TCHP). In line with these results, measurements of the BLM stationary conductance indicated that membrane permeability for C4TCHP is 2.5 times higher than that for C4TPP. Values of the difference in the free energy of ion solvation in water and octane calculated using the density functional theory and the polarizable continuum solvent model were similar for methyltriphenylphosphonium, tricyclohexylmethylphosphonium and trihexylmethylphosphonium. Our results prove that both cyclic and aromatic moieties are not necessary for lipophilic ions to effectively permeate through lipid membranes.
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Affiliation(s)
- Tatyana I Rokitskaya
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119991, Russia.
| | - Elena A Kotova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Victor B Luzhkov
- Department of Kinetics of Chemical and Biological Processes, Institute of Problems of Chemical Physics, Russian Academy of Sciences, acad. Semenov av. 1, Chernogolovka, Moscow Region 142432, Russia; Department of Fundamental Physical and Chemical Engineering, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Roman S Kirsanov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119991, Russia
| | | | - Galina A Korshunova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Vadim N Tashlitsky
- Department of Chemistry, Lomonosov Moscow State University, Moscow 119991, Russia
| | - Yuri N Antonenko
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119991, Russia
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10
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Effect of Cholesterol on the Dipole Potential of Lipid Membranes. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1115:135-154. [DOI: 10.1007/978-3-030-04278-3_6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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11
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Gomes B, Gonçalves S, Disalvo A, Hollmann A, Santos NC. Effect of 25-hydroxycholesterol in viral membrane fusion: Insights on HIV inhibition. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1171-1178. [PMID: 29408450 DOI: 10.1016/j.bbamem.2018.02.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 01/08/2018] [Accepted: 02/01/2018] [Indexed: 12/15/2022]
Abstract
Recently, it was demonstrated that 25-hydroxycholesterol (25HC), an oxidized cholesterol derivative, inhibits human immunodeficiency virus type 1 (HIV) entry into its target cells. However, the mechanisms involved in this action have not yet been established. The aim of this work was to study the effects of 25HC in biomembrane model systems and at the level of HIV fusion peptide (HIV-FP). Integration of different biophysical approaches was made in the context of HIV fusion process, to clarify the changes at membrane level due to the presence of 25HC that result in the suppressing of viral infection. Lipid vesicles mimicking mammalian and HIV membranes were used on spectroscopy assays and lipid monolayers in surface pressure studies. Peptide-induced lipid mixing assays were performed by Förster resonance energy transfer to calculate fusion efficiency. Liposome fusion is reduced by 50% in the presence of 25HC, comparatively to cholesterol. HIV-FP conformation was assessed by infrared assays and it relies on sterol nature. Anisotropy, surface pressure and dipole potential assays indicate that the conversion of cholesterol in 25HC leads to a loss of the cholesterol modulating effect on the membrane. With different biophysical techniques, we show that 25HC affects the membrane fusion process through the modification of lipid membrane properties, and by direct alterations on HIV-FP structure. The present data support a broad antiviral activity for 25HC.
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Affiliation(s)
- Bárbara Gomes
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisbon, Portugal
| | - Sónia Gonçalves
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisbon, Portugal
| | - Anibal Disalvo
- Laboratory of Biointerfaces and Biomimetic Systems, CITSE, University of Santiago del Estero, -CONICET, 4200 Santiago del Estero, Argentina
| | - Axel Hollmann
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisbon, Portugal; Laboratory of Biointerfaces and Biomimetic Systems, CITSE, University of Santiago del Estero, -CONICET, 4200 Santiago del Estero, Argentina; Laboratory of Molecular Microbiology, Institute of Basic and Applied Microbiology, University of Quilmes, B1876BXD Bernal, Argentina
| | - Nuno C Santos
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisbon, Portugal.
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12
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Shrestha R, Anderson CM, Cardenas AE, Elber R, Webb LJ. Direct Measurement of the Effect of Cholesterol and 6-Ketocholestanol on the Membrane Dipole Electric Field Using Vibrational Stark Effect Spectroscopy Coupled with Molecular Dynamics Simulations. J Phys Chem B 2017; 121:3424-3436. [PMID: 28071910 PMCID: PMC5398937 DOI: 10.1021/acs.jpcb.6b09007] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Biological membranes are heterogeneous structures with complex electrostatic profiles arising from lipids, sterols, membrane proteins, and water molecules. We investigated the effect of cholesterol and its derivative 6-ketocholestanol (6-kc) on membrane electrostatics by directly measuring the dipole electric field (F⃗d) within lipid bilayers containing cholesterol or 6-kc at concentrations of 0-40 mol% through the vibrational Stark effect (VSE). We found that adding low concentrations of cholesterol, up to ∼10 mol %, increases F⃗d, while adding more cholesterol up to 40 mol% lowers F⃗d. In contrast, we measured a monotonic increase in F⃗d as 6-kc concentration increased. We propose that this membrane electric field is affected by multiple factors: the polarity of the sterol molecules, the reorientation of the phospholipid dipole due to sterol, and the impact of the sterol on hydrogen bonding with surface water. We used molecular dynamics simulations to examine the distribution of phospholipids, sterol, and helix in bilayers containing these sterols. At low concentrations, we observed clustering of sterols near the vibrational probe whereas at high concentrations, we observed spatial correlation between the positions of the sterol molecules. This work demonstrates how a one-atom difference in a sterol changes the physicochemical and electric field properties of the bilayer.
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Affiliation(s)
- Rebika Shrestha
- Department of Chemistry, ‡Institute for Cell and Molecular Biology, §Center for Nano- and Molecular Science and Technology, and ∥Institute for Computational Engineering and Sciences, The University of Texas at Austin , Austin, Texas 78712, United States
| | - Cari M Anderson
- Department of Chemistry, ‡Institute for Cell and Molecular Biology, §Center for Nano- and Molecular Science and Technology, and ∥Institute for Computational Engineering and Sciences, The University of Texas at Austin , Austin, Texas 78712, United States
| | - Alfredo E Cardenas
- Department of Chemistry, ‡Institute for Cell and Molecular Biology, §Center for Nano- and Molecular Science and Technology, and ∥Institute for Computational Engineering and Sciences, The University of Texas at Austin , Austin, Texas 78712, United States
| | - Ron Elber
- Department of Chemistry, ‡Institute for Cell and Molecular Biology, §Center for Nano- and Molecular Science and Technology, and ∥Institute for Computational Engineering and Sciences, The University of Texas at Austin , Austin, Texas 78712, United States
| | - Lauren J Webb
- Department of Chemistry, ‡Institute for Cell and Molecular Biology, §Center for Nano- and Molecular Science and Technology, and ∥Institute for Computational Engineering and Sciences, The University of Texas at Austin , Austin, Texas 78712, United States
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13
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Barrientos G, Sánchez-Aguilera P, Jaimovich E, Hidalgo C, Llanos P. Membrane Cholesterol in Skeletal Muscle: A Novel Player in Excitation-Contraction Coupling and Insulin Resistance. J Diabetes Res 2017; 2017:3941898. [PMID: 28367451 PMCID: PMC5358446 DOI: 10.1155/2017/3941898] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 02/06/2017] [Indexed: 11/17/2022] Open
Abstract
Membrane cholesterol is critical for signaling processes in a variety of tissues. We will address here current evidence supporting an emerging role of cholesterol on excitation-contraction coupling and glucose transport in skeletal muscle. We have centered our review on the transverse tubule system, a complex network of narrow plasma membrane invaginations that propagate membrane depolarization into the fiber interior and allow nutrient delivery into the fibers. We will discuss current evidence showing that transverse tubule membranes have remarkably high cholesterol levels and we will address how modifications of cholesterol content influence excitation-contraction coupling. In addition, we will discuss how membrane cholesterol levels affect glucose transport by modulating the insertion into the membrane of the main insulin-sensitive glucose transporter GLUT4. Finally, we will address how the increased membrane cholesterol levels displayed by obese animals, which also present insulin resistance, affect these two particular skeletal muscle functions.
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Affiliation(s)
- G. Barrientos
- Center for Molecular Studies of the Cell, Facultad de Medicina, Universidad de Chile, Santiago, Chile
- Physiology and Biophysics Program, ICBM, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - P. Sánchez-Aguilera
- Center for Molecular Studies of the Cell, Facultad de Medicina, Universidad de Chile, Santiago, Chile
- Institute for Research in Dental Sciences, Facultad de Odontología, Universidad de Chile, Santiago, Chile
| | - E. Jaimovich
- Center for Molecular Studies of the Cell, Facultad de Medicina, Universidad de Chile, Santiago, Chile
- Cell and Molecular Biology Program, ICBM, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - C. Hidalgo
- Center for Molecular Studies of the Cell, Facultad de Medicina, Universidad de Chile, Santiago, Chile
- Physiology and Biophysics Program, ICBM, Facultad de Medicina, Universidad de Chile, Santiago, Chile
- BNI, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - P. Llanos
- Center for Molecular Studies of the Cell, Facultad de Medicina, Universidad de Chile, Santiago, Chile
- Institute for Research in Dental Sciences, Facultad de Odontología, Universidad de Chile, Santiago, Chile
- *P. Llanos:
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14
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Rokitskaya TI, Kosenko ID, Sivaev IB, Antonenko YN, Bregadze VI. Fast flip–flop of halogenated cobalt bis(dicarbollide) anion in a lipid bilayer membrane. Phys Chem Chem Phys 2017; 19:25122-25128. [DOI: 10.1039/c7cp04207h] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Halogenation dramatically affects the flip–flop of cobalt bis(dicarbollide) across the lipid membrane causing acceleration (Cl, Br, I) or deceleration (F).
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Affiliation(s)
- Tatyana I. Rokitskaya
- Belozersky Institute of Physico-Chemical Biology
- Lomonosov Moscow State University
- Moscow 119991
- Russian Federation
| | - Irina D. Kosenko
- A. N. Nesmeyanov Institute of Organoelement Compounds
- Russian Academy of Sciences
- Moscow
- Russian Federation
| | - Igor B. Sivaev
- A. N. Nesmeyanov Institute of Organoelement Compounds
- Russian Academy of Sciences
- Moscow
- Russian Federation
| | - Yuri N. Antonenko
- Belozersky Institute of Physico-Chemical Biology
- Lomonosov Moscow State University
- Moscow 119991
- Russian Federation
| | - Vladimir I. Bregadze
- A. N. Nesmeyanov Institute of Organoelement Compounds
- Russian Academy of Sciences
- Moscow
- Russian Federation
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15
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Pearlstein RA, Dickson CJ, Hornak V. Contributions of the membrane dipole potential to the function of voltage-gated cation channels and modulation by small molecule potentiators. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1859:177-194. [PMID: 27836643 DOI: 10.1016/j.bbamem.2016.11.005] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 10/28/2016] [Accepted: 11/06/2016] [Indexed: 01/27/2023]
Abstract
The membrane dipole potential (Ψd) constitutes one of three electrical potentials generated by cell membranes. Ψd arises from the unfavorable parallel alignment of phospholipid and water dipoles, and varies in magnitude both longitudinally and laterally across the bilayer according to membrane composition and phospholipid packing density. In this work, we propose that dynamic counter-balancing between Ψd and the transmembrane potential (ΔΨm) governs the conformational state transitions of voltage-gated ion channels. Ψd consists of 1) static outer, and dynamic inner leaflet components (Ψd(extra) and Ψd(intra), respectively); and 2) a transmembrane component (ΔΨd(inner-outer)), ariing from differences in intra- and extracellular leaflet composition. Ψd(intra), which transitions between high and low energy states (Ψd(intra, high) and Ψd(intra, low)) as a function of channel conformation, is transduced by the pore domain. ΔΨd(inner-outer) is transduced by the voltage-sensing (VS) domain in summation with ΔΨm. Potentiation of voltage-gated ion channels is of interest for the treatment of cardiac, neuronal, and other disorders arising from inherited/acquired ion channel dysfunction. Potentiators are widely believed to alter the rates and voltage-dependencies of channel gating transitions by binding to pockets in the membrane-facing and other regions of ion channel targets. Here, we propose that potentiators alter Ψd(intra) and/or Ψd(extra), thereby increasing or decreasing the energy barriers governing channel gating transitions. We used quantum mechanical and molecular dynamics (MD) simulations to predict the overall Ψd-modulating effects of a series of published positive hERG potentiators partitioned into model DOPC bilayers. Our findings suggest a strong correlation between the magnitude of Ψd-lowering and positive hERG potentiation across the series.
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Affiliation(s)
- Robert A Pearlstein
- Global Discovery Chemistry, Computer-Aided Drug Discovery, Novartis Institutes for BioMedical Research, 181 Mass Ave., Cambridge, MA 02139, USA.
| | - Callum J Dickson
- Global Discovery Chemistry, Computer-Aided Drug Discovery, Novartis Institutes for BioMedical Research, 181 Mass Ave., Cambridge, MA 02139, USA
| | - Viktor Hornak
- Global Discovery Chemistry, Computer-Aided Drug Discovery, Novartis Institutes for BioMedical Research, 181 Mass Ave., Cambridge, MA 02139, USA
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16
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Zhang HY, Xu Q, Wang YK, Zhao TZ, Hu D, Wei DQ. Passive Transmembrane Permeation Mechanisms of Monovalent Ions Explored by Molecular Dynamics Simulations. J Chem Theory Comput 2016; 12:4959-4969. [PMID: 27599103 DOI: 10.1021/acs.jctc.6b00695] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Passive or unassisted ion permeation through lipid bilayers involves a type of rare events by which cells regulate their salt concentrations and pH. It is important to understand its mechanism in order to develop technologies of, for example, delivering or maintaining small drug-like molecules inside cells. In earlier simulations of passive ion permeations, the commonly used sampling methods usually define the positions of ions relative to the membrane as a measure of permeation, i.e., the collective variable, ignoring the active participations of other particles. Newly defined collective variables involving the movements of ions, lipids, and water molecules allow us to identify the transition paths on the free energy landscape using the 2D umbrella sampling techniques. In this work, this technique was used to study the permeation processes of some well-known ions, sodium, potassium, and chloride. It is found permeations of sodium and potassium are assisted by important lipid bilayer deformations and massive water solvation, while chloride may not. Chloride may have two different possible pathways, in which the energetic favorable one is similar to the solubility-diffusion model. The free energy barriers for the permeation of these ions are in semiquantitative agreement with experiments. Further analyses on the distributions of oxygens and interaction energies suggest the electrostatic interactions between ions and polar headgroups of lipids may greatly influence membrane deformation as well as the water wire and furthermore the free energy barriers of waterwire mediated pathways. For chloride, the nonwaterwire pathway may be energetically favorable.
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Affiliation(s)
- Hui-Yuan Zhang
- State Key Laboratory of Microbial Metabolism and School of Life Science and Biotechnology and ‡Department of Mathematics, Institute of Natural Science, and MOE-LEC, Shanghai Jiao Tong University , Shanghai 200240, China
| | - Qin Xu
- State Key Laboratory of Microbial Metabolism and School of Life Science and Biotechnology and ‡Department of Mathematics, Institute of Natural Science, and MOE-LEC, Shanghai Jiao Tong University , Shanghai 200240, China
| | - Yu-Kun Wang
- State Key Laboratory of Microbial Metabolism and School of Life Science and Biotechnology and ‡Department of Mathematics, Institute of Natural Science, and MOE-LEC, Shanghai Jiao Tong University , Shanghai 200240, China
| | - Tang-Zhen Zhao
- State Key Laboratory of Microbial Metabolism and School of Life Science and Biotechnology and ‡Department of Mathematics, Institute of Natural Science, and MOE-LEC, Shanghai Jiao Tong University , Shanghai 200240, China
| | - Dan Hu
- State Key Laboratory of Microbial Metabolism and School of Life Science and Biotechnology and ‡Department of Mathematics, Institute of Natural Science, and MOE-LEC, Shanghai Jiao Tong University , Shanghai 200240, China
| | - Dong-Qing Wei
- State Key Laboratory of Microbial Metabolism and School of Life Science and Biotechnology and ‡Department of Mathematics, Institute of Natural Science, and MOE-LEC, Shanghai Jiao Tong University , Shanghai 200240, China
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17
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Abkin SV, Ostroumova OS, Komarova EY, Meshalkina DA, Shevtsov MA, Margulis BA, Guzhova IV. Phloretin increases the anti-tumor efficacy of intratumorally delivered heat-shock protein 70 kDa (HSP70) in a murine model of melanoma. Cancer Immunol Immunother 2016; 65:83-92. [PMID: 26646850 PMCID: PMC11028722 DOI: 10.1007/s00262-015-1778-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Accepted: 11/19/2015] [Indexed: 10/22/2022]
Abstract
Recombinant HSP70 chaperone exerts a profound anticancer effect when administered intratumorally. This action is based on the ability of HSP70 to penetrate tumor cells and extract its endogenous homolog. To enhance the efficacy of HSP70 cycling, we employed phloretin, a flavonoid that enhances the pore-forming activity of the chaperone on artificial membranes. Phloretin increased the efficacy of HSP70 penetration in B16 mouse melanoma cells and K-562 human erythroblasts; this was accompanied with increased transport of the endogenous HSP70 to the plasma membrane. Importantly, treatment with HSP70 combined with phloretin led to the elevation of cell sensitivity to cytotoxic lymphocytes by 16-18 % compared to treatment with the chaperone alone. The incubation of K-562 cells with biotinylated HSP70 and phloretin increased the amount of the chaperone released from cells, suggesting that chaperone cycling could trigger a specific anti-tumor response. We studied the effect of the combination of HSP70 and phloretin using B16 melanoma and a novel method of HSP70-gel application. We found that the addition of phloretin to the gel reduced tumor weight almost fivefold compared with untreated mice, while the life span of the animals extended from 25 to 39 days. The increased survival was corroborated by the activation of innate and adaptive immunity; interestingly, HSP70 was more active in induction of CD8+ cell-mediated toxicity and γIFN production while phloretin contributed largely to the CD56+ cell response. In conclusion, the combination of HSP70 with phloretin could be a novel treatment for efficient immunotherapy of intractable cancers such as skin melanoma.
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Affiliation(s)
- Sergey V Abkin
- Institute of Cytology of Russian Academy of Sciences, Tikhoretsky Prospect, 4, St. Petersburg, Russia, 194064
| | - Olga S Ostroumova
- Institute of Cytology of Russian Academy of Sciences, Tikhoretsky Prospect, 4, St. Petersburg, Russia, 194064
| | - Elena Y Komarova
- Institute of Cytology of Russian Academy of Sciences, Tikhoretsky Prospect, 4, St. Petersburg, Russia, 194064
| | - Darya A Meshalkina
- Institute of Cytology of Russian Academy of Sciences, Tikhoretsky Prospect, 4, St. Petersburg, Russia, 194064
| | - Maxim A Shevtsov
- Institute of Cytology of Russian Academy of Sciences, Tikhoretsky Prospect, 4, St. Petersburg, Russia, 194064
| | - Boris A Margulis
- Institute of Cytology of Russian Academy of Sciences, Tikhoretsky Prospect, 4, St. Petersburg, Russia, 194064
| | - Irina V Guzhova
- Institute of Cytology of Russian Academy of Sciences, Tikhoretsky Prospect, 4, St. Petersburg, Russia, 194064.
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18
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Efimova SS, Ostroumova OS. Modifiers of the Dipole Potential of Lipid Bilayers. Acta Naturae 2015; 7:70-9. [PMID: 26798493 PMCID: PMC4717251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
This paper assesses the magnitude of change in the dipole potential (φd) of membranes caused by the adsorption of modifiers on lipid bilayers of various compositions. We tested flavonoids, muscle relaxants, thyroid hormones, and xanthene and styrylpyridinium dyes in order to assess their dipole-modifying properties. A quantitative description of the modifying action of flavonoids, muscle relaxants, thyroid hormones, and xanthene dyes is shown as the ratio of the maximum change in the bilayer dipole potential upon saturation and the absolute φd value of the unmodified membrane. The slopes of the linear relationship between the increase in the dipole potential of phospholipid bilayers and the concentration of styrylpyridinium dyes in membrane-bathing solutions were found. We described the relationships between the change in φd and the chemical structure of modifiers, as well as the charge and spontaneous curvature of lipid monolayers.
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Affiliation(s)
- S. S. Efimova
- Institute of Cytology of the Russian Academy of Sciences, Tikhoretsky av. 4, St. Petersburg 194064 , Russia
| | - O. S. Ostroumova
- Institute of Cytology of the Russian Academy of Sciences, Tikhoretsky av. 4, St. Petersburg 194064 , Russia
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19
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Molecular PET Imaging of Cyclophosphamide Induced Apoptosis with 18F-ML-8. BIOMED RESEARCH INTERNATIONAL 2015; 2015:317403. [PMID: 25977920 PMCID: PMC4420799 DOI: 10.1155/2015/317403] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 03/28/2015] [Indexed: 01/08/2023]
Abstract
In this paper, a novel small-molecular apoptotic PET imaging probe, 18F-ML-8 with a malonate motif structure, is presented and discussed. After study, the small tracer that belongs to a member of ApoSense family is proved to be capable of imaging merely apoptotic regions in the CTX treated tumor-bearing mice. The experimental result is further confirmed by in vitro cell binding assays and TUNEL staining assay. As a result, 18F-ML-8 could be used for noninvasive visualization of apoptosis induced by antitumor chemotherapy.
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20
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The dehydration dynamics of a model cell membrane induced by cholesterol analogue 6-ketocholestanol investigated using sum frequency generation vibrational spectroscopy. Sci China Chem 2015. [DOI: 10.1007/s11426-014-5308-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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21
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Modifiers of membrane dipole potentials as tools for investigating ion channel formation and functioning. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2015; 315:245-97. [PMID: 25708465 DOI: 10.1016/bs.ircmb.2014.12.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Electrostatic fields generated on and within biological membranes play a fundamental role in key processes in cell functions. The role of the membrane dipole potential is of particular interest because of its powerful impact on membrane permeability and lipid-protein interactions, including protein insertion, oligomerization, and function. The membrane dipole potential is defined by the orientation of electric dipoles of lipid headgroups, fatty acid carbonyl groups, and membrane-adsorbed water. As a result, the membrane interior is several hundred millivolts more positive than the external aqueous phase. This potential decrease depends on the lipid, and especially sterol, composition of the membrane. The adsorption of certain electroneutral molecules known as dipole modifiers may also lead to significant changes in the magnitude of the potential decrease. These agents are widely used to study the effects of the dipole potential on membrane transport. This review presents a critical analysis of a variety of data from studies dedicated to ion channel formation and functioning in membranes with different dipole potentials. The types of ion channels found in cellular membranes and pores formed by antimicrobial agents and toxins in artificial lipid membranes are summarized. The mechanisms underlying the influence of the membrane dipole potential on ion channel activity, including dipole-dipole and charge-dipole interactions in the pores and in membranes, are discussed. A hypothesis, in which lipid rafts in both model and cellular membranes also modulate ion channel activity by virtue of an increased or decreased dipole potential, is also considered.
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Shrestha R, Cardenas AE, Elber R, Webb LJ. Measurement of the membrane dipole electric field in DMPC vesicles using vibrational shifts of p-cyanophenylalanine and molecular dynamics simulations. J Phys Chem B 2015; 119:2869-76. [PMID: 25602635 DOI: 10.1021/jp511677j] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The magnitude of the membrane dipole field was measured using vibrational Stark effect (VSE) shifts of nitrile oscillators placed on the unnatural amino acid p-cyanophenylalanine (p-CN-Phe) added to a peptide sequence at four unique positions. These peptides, which were based on a repeating alanine-leucine motif, intercalated into small unilamellar DMPC vesicles which formed an α-helix as confirmed by circular dichroic (CD) spectroscopy. Molecular dynamics simulations of the membrane-intercalated helix containing two of the nitrile probes, one near the headgroup region of the lipid (αLAX(25)) and one buried in the interior of the bilayer (αLAX(16)), were used to examine the structure of the nitrile with respect to the membrane normal, the assumed direction of the dipole field, by quantifying both a small tilt of the helix in the bilayer and conformational rotation of the p-CN-Phe side chain at steady state. Vibrational absorption energies of the nitrile oscillator at each position showed a systematic blue shift as the nitrile was stepped toward the membrane interior; for several different concentrations of peptide, the absorption energy of the nitrile located in the middle of the bilayer was ∼3 cm(-1) greater than that of the nitrile closest to the surface of the membrane. Taken together, the measured VSE shifts and nitrile orientations within the membrane resulted in an absolute magnitude of 8-11 MV/cm for the dipole field, at the high end of the range of possible values that have been accumulated from a variety of indirect measurements. Implications for this are discussed.
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Affiliation(s)
- Rebika Shrestha
- Department of Chemistry, ‡Institute for Cell and Molecular Biology, §Center for Nano- and Molecular Science and Technology, and ∥Institute for Computational Engineering and Sciences, The University of Texas at Austin , Austin, Texas 78712, United States
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23
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Disalvo EA, Hollmann A, Martini MF. Hydration in Lipid Monolayers: Correlation of Water Activity and Surface Pressure. Subcell Biochem 2015; 71:213-231. [PMID: 26438267 DOI: 10.1007/978-3-319-19060-0_9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
In order to give a physical meaning to each region of the membrane we define the interphase as the region in a lipid membrane corresponding to the polar head groups imbibed in water with net different properties than the hydrocarbon region and the water phase. The interphase region is analyzed under the scope of thermodynamics of surface and solutions based on the definition of Defay-Prigogine of an interphase and the derivation that it has in the understanding of membrane processeses in the context of biological response. In the view of this approach, the complete monolayer is considered as the lipid layer one molecule thick plus the bidimensional solution of the polar head groups inherent to it (the interphase region). Surface water activity appears as a common factor for the interaction of several aqueous soluble and surface active proteins with lipid membranes of different composition. Protein perturbation can be measured by changes in the surface pressure of lipid monolayers at different initial water surface activities. As predicted by solution chemistry, the increase of surface pressure is independent of the particle nature that dissolves. Therefore, membranes give a similar response in terms of the determined surface states given by water activity independent of the protein or peptide.
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Affiliation(s)
- E Anibal Disalvo
- Laboratorio de Biointerfases y Sistemas Biomimeticos, Centro de Investigacion y Transferencia de Santiago del Estero, Universidad Nacional de Santiago del Estero-Consejo Nacional de Investigaciones Científicas y Técnicas, 4200, Santiago del Estero, Argentina.
| | - Axel Hollmann
- Laboratorio de Biointerfases y Sistemas Biomimeticos, Centro de Investigacion y Transferencia de Santiago del Estero, Universidad Nacional de Santiago del Estero-Consejo Nacional de Investigaciones Científicas y Técnicas, 4200, Santiago del Estero, Argentina
| | - M Florencia Martini
- Instituto de Química y Metabolismo del Fármaco, IQUIMEFA UBA-CONICET, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956 PP (1113), Buenos Aires, Argentina.
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Bittermann K, Spycher S, Endo S, Pohler L, Huniar U, Goss KU, Klamt A. Prediction of Phospholipid–Water Partition Coefficients of Ionic Organic Chemicals Using the Mechanistic Model COSMOmic. J Phys Chem B 2014; 118:14833-42. [DOI: 10.1021/jp509348a] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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25
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Hidaka Y, Asami K. Measurement of dipole potential in bilayer lipid membranes by dielectric spectroscopy. J Membr Biol 2014; 247:721-7. [PMID: 24935731 DOI: 10.1007/s00232-014-9697-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Accepted: 05/29/2014] [Indexed: 10/25/2022]
Abstract
Planar bilayer lipid membranes formed from egg phosphatidylcholine in aqueous media containing the lipophilic anion, dipicrylamine (DPA), were studied by dielectric spectroscopy over a frequency range of 10 Hz-10 MHz. The membranes showed dielectric relaxation due to the translocation of DPA between the membrane interfaces. Incorporating either cholesterol or 6-ketocholestanol into the membranes increased the characteristic frequency of the relaxation, which is proportional to the translocation rate constant of DPA. The results suggested that the sterol dipoles induced positive potential changes within the membrane interior. The changes of the dipole potential were 70 mV for cholesterol and 150 mV for 6-ketocholestanol when the sterol mole fraction was 0.67. The opposite effect was caused by phloretin added to the aqueous media, and the maximum dipole potential change was -90 mV at 100 μM.
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Affiliation(s)
- Yuta Hidaka
- Institute for Chemical Research, Kyoto University, Uji, Kyoto, 611-0011, Japan
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26
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Zhytniakivska O, Trusova V, Gorbenko G, Kirilova E, Kalnina I, Kirilov G, Molotkovsky J, Tulkki J, Kinnunen P. Location of Novel Benzanthrone Dyes in Model Membranes as Revealed by Resonance Energy Transfer. J Fluoresc 2014; 24:899-907. [DOI: 10.1007/s10895-014-1370-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Accepted: 02/24/2014] [Indexed: 01/21/2023]
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Ma S, Li H, Tian K, Ye S, Luo Y. In Situ and Real-Time SFG Measurements Revealing Organization and Transport of Cholesterol Analogue 6-Ketocholestanol in a Cell Membrane. J Phys Chem Lett 2014; 5:419-424. [PMID: 26276585 DOI: 10.1021/jz402537w] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Cholesterol organization and transport within a cell membrane are essential for human health and many cellular functions yet remain elusive so far. Using cholesterol analogue 6-ketocholestanol (6-KC) as a model, we have successfully exploited sum frequency generation vibrational spectroscopy (SFG-VS) to track the organization and transport of cholesterol in a membrane by combining achiral-sensitive ssp (ppp) and chiral-sensitive psp polarization measurements. It is found that 6-KC molecules are aligned at the outer leaflet of the DMPC lipid bilayer with a tilt angle of about 10°. 6-KC organizes itself by forming an α-β structure at low 6-KC concentration and most likely a β-β structure at high 6-KC concentration. Among all proposed models, our results favor the so-called umbrella model with formation of a 6-KC cluster. Moreover, we have found that the long anticipated flip-flop motion of 6-KC in the membrane takes time to occur, at least much longer than previously thought. All of these interesting findings indicate that it is critical to explore in situ, real-time, and label-free methodologies to obtain a precise molecular description of cholesterol's behavior in membranes. This study represents the first application of SFG to reveal the cholesterol-lipid interaction mechanism at the molecular level.
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Affiliation(s)
| | | | | | | | - Yi Luo
- ⊥Department of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology, S-10961 Stockholm, Sweden
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28
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Surface and hysteresis properties of lipid interphases composed by head group substituted phosphatidylethanolamines. Colloids Surf B Biointerfaces 2014; 113:243-8. [DOI: 10.1016/j.colsurfb.2013.08.044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 08/27/2013] [Accepted: 08/28/2013] [Indexed: 11/18/2022]
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29
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Dodecyl and octyl esters of fluorescein as protonophores and uncouplers of oxidative phosphorylation in mitochondria at submicromolar concentrations. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2014; 1837:149-58. [DOI: 10.1016/j.bbabio.2013.09.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 09/12/2013] [Accepted: 09/18/2013] [Indexed: 11/18/2022]
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30
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Electrogenic proton transport across lipid bilayer membranes mediated by cationic derivatives of rhodamine 19: comparison with anionic protonophores. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2013; 42:477-85. [DOI: 10.1007/s00249-013-0898-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Revised: 01/24/2013] [Accepted: 03/21/2013] [Indexed: 10/27/2022]
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31
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Luchian T. The modulatory effect of calcium ions upon alamethicin monomers uptake on artificial phospholipid membranes. J Biol Phys 2013; 31:23-33. [PMID: 23345882 DOI: 10.1007/s10867-005-3303-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
In this paper, we examined the influence exerted by calcium ions upon physical properties of lipids constituting an artificial membrane. Our strategy was to study changes on alamethicin oligomer kinetic features embedded into such an artificial membrane. At neutral pH and in the presence of calcium ions, we observed an increase in the number of alamethicin monomers that oligomerize within the membrane, forming a multi-substate nanopore. We make the argument that calcium ions binding within the interface between the hydrophobic and the hydrophilic regions of the biomembrane causes a sizeable alteration of the physical properties of neutral lipid membranes. This in turn is seen to influence the translocation rates of alamethicin monomers from the solution adjacent to the biomembrane and leads to an augmentation in the subunit composition of the alamethicin oligomers, leaving the electrical conductance of the substates and their kinetics mainly unchanged.
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Affiliation(s)
- Tudor Luchian
- Faculty of Physics, Department of Biophysics and Medical Physics, 'Alexandru I. Cuza' University, Blvd. Carol I no 11, Iasi, RO-6600 Romania
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Abstract
There are three kinds of membrane potentials: the surface potentials, resulting from the accumulation of charges at the membrane surfaces; the transmembrane potential, determined by imbalance of charge in the aqueous solutions; and the dipole potential, a membrane-internal potential from the dipolar components of the phospholipids and interface water. The absolute value of the dipole potential has been very difficult to measure, although its value has been estimated to be in the range of 200-1,000 mV from ion translocation rates (determined by the planar lipid bilayer method), the surface potential of lipid monolayers (determined by the lipid monolayer method), molecular-dynamics calculations, and electron scattering using cryoelectron microscopy (cryo-EM). Spectroscopy methods have also been used to monitor the dipole potential changes on the basis of the observed fluorescence changes of voltage-sensitive probes. The dipole potential accounts for the much larger permeability of a bare phospholipid membrane to anions than cations and affects the conformation and function of membrane proteins.
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Affiliation(s)
- Liguo Wang
- Department of Biological Structure, University of Washington, Seattle, Washington 98195, USA.
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Berkovich AK, Lukashev EP, Melik-Nubarov NS. Dipole potential as a driving force for the membrane insertion of polyacrylic acid in slightly acidic milieu. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1818:375-83. [DOI: 10.1016/j.bbamem.2011.06.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Revised: 05/08/2011] [Accepted: 06/06/2011] [Indexed: 02/02/2023]
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35
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Zhan H, Lazaridis T. Influence of the membrane dipole potential on peptide binding to lipid bilayers. Biophys Chem 2011; 161:1-7. [PMID: 22100997 DOI: 10.1016/j.bpc.2011.10.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2011] [Revised: 10/21/2011] [Accepted: 10/25/2011] [Indexed: 12/15/2022]
Abstract
The implicit membrane model IMM1 is extended to include the membrane dipole potential and applied to molecular dynamics simulations of the helical peptides alamethicin, WALP23, influenza hemagglutinin fusion peptide, HIV fusion peptide, magainin, and the pre-sequence of cytochrome c oxidase subunit IV (p25). The results show that the orientation of the peptides in the membrane can be influenced by the dipole potential. The binding affinity of all peptides except for the hemagglutinin fusion peptide decreases upon increase of the dipole potential. The changes in both orientation and binding affinity are explained by the interaction of the dipole potential with the helix backbone dipole and ionic side-chains. In general, peptides that tend to insert the N-terminus in the membrane and/or have positively charged side chains will lose binding affinity upon increase of the dipole potential.
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Affiliation(s)
- Huan Zhan
- Department of Chemistry, City College of New York/CUNY, New York, NY 10031, USA
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36
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Mereuta L, Asandei A, Luchian T. Meet me on the other side: trans-bilayer modulation of a model voltage-gated ion channel activity by membrane electrostatics asymmetry. PLoS One 2011; 6:e25276. [PMID: 21980414 PMCID: PMC3181326 DOI: 10.1371/journal.pone.0025276] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Accepted: 08/30/2011] [Indexed: 12/03/2022] Open
Abstract
While it is accepted that biomembrane asymmetry is generated by proteins and phospholipids distribution, little is known about how electric changes manifested in a monolayer influence functional properties of proteins localized on the opposite leaflet. Herein we used single-molecule electrophysiology and investigated how asymmetric changes in the electrostatics of an artificial lipid membrane monolayer, generated oppositely from where alamethicin - a model voltage-gated ion channel - was added, altered peptide activity. We found that phlorizin, a membrane dipole potential lowering amphiphile, augmented alamethicin activity and transport features, whereas the opposite occurred with RH-421, which enhances the monolayer dipole potential. Further, the monolayer surface potential was decreased via adsorption of sodium dodecyl sulfate, and demonstrated that vectorial modification of it also affected the alamethicin activity in a predictive manner. A new paradigm is suggested according to which asymmetric changes in the monolayer dipole and surface potential extend their effects spatially by altering the intramembrane potential, whose gradient is sensed by distantly located peptides.
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Affiliation(s)
- Loredana Mereuta
- Department of Physics, Laboratory of Molecular Biophysics and Medical Physics, Alexandru I. Cuza University, Iasi, Romania
| | - Alina Asandei
- Department of Physics, Laboratory of Molecular Biophysics and Medical Physics, Alexandru I. Cuza University, Iasi, Romania
| | - Tudor Luchian
- Department of Physics, Laboratory of Molecular Biophysics and Medical Physics, Alexandru I. Cuza University, Iasi, Romania
- * E-mail:
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37
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Warshaviak DT, Muellner MJ, Chachisvilis M. Effect of membrane tension on the electric field and dipole potential of lipid bilayer membrane. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2011; 1808:2608-17. [PMID: 21722624 DOI: 10.1016/j.bbamem.2011.06.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2011] [Revised: 06/08/2011] [Accepted: 06/14/2011] [Indexed: 12/15/2022]
Abstract
The dipole potential of lipid bilayer membrane controls the difference in permeability of the membrane to oppositely charged ions. We have combined molecular dynamics (MD) simulations and experimental studies to determine changes in electric field and electrostatic potential of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) lipid bilayer in response to applied membrane tension. MD simulations based on CHARMM36 force field showed that electrostatic potential of DOPC bilayer decreases by ~45mV in the physiologically relevant range of membrane tension values (0 to 15dyn/cm). The electrostatic field exhibits a peak (~0.8×10(9)V/m) near the water/lipid interface which shifts by 0.9Å towards the bilayer center at 15dyn/cm. Maximum membrane tension of 15dyn/cm caused 6.4% increase in area per lipid, 4.7% decrease in bilayer thickness and 1.4% increase in the volume of the bilayer. Dipole-potential sensitive fluorescent probes were used to detect membrane tension induced changes in DOPC vesicles exposed to osmotic stress. Experiments confirmed that dipole potential of DOPC bilayer decreases at higher membrane tensions. These results are suggestive of a potentially new mechanosensing mechanism by which mechanically induced structural changes in the lipid bilayer membrane could modulate the function of membrane proteins by altering electrostatic interactions and energetics of protein conformational states.
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38
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Ostroumova OS, Efimova SS, Schagina LV. 5- and 4'-Hydroxylated flavonoids affect voltage gating of single alpha-hemolysin pore. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2011; 1808:2051-8. [PMID: 21527242 DOI: 10.1016/j.bbamem.2011.04.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Revised: 03/27/2011] [Accepted: 04/11/2011] [Indexed: 10/18/2022]
Abstract
Molecular mechanisms of the influence of flavonoids on the voltage gating of a single alpha-hemolysin channel in planar lipid membranes are studied. It is shown that the addition of flavonoids hydroxylated in position 5 of the A-ring and in position 4' of the B-ring into bilayer bathing solution shifts the voltage dependence of channel switching from high- to low-conductance states to voltages nearer zero. It is concluded that the effect is likely to be attributed to a specific interaction of at least three flavonoid molecules with the voltage sensor of an alpha-hemolysin pore. Possible flavonoid binding sites and identification of amino acid residues included into the voltage sensor domain of the alpha-hemolysin channel are discussed.
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Affiliation(s)
- Olga S Ostroumova
- Institute of Cytology of the Russian Academy of Sciences, St. Petersburg 194064, Russia.
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39
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Quantitative assessment of peptide–lipid interactions. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2010; 1798:1999-2012. [DOI: 10.1016/j.bbamem.2010.07.012] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2010] [Revised: 07/13/2010] [Accepted: 07/13/2010] [Indexed: 11/23/2022]
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40
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Ostroumova OS, Malev VV, Ilin MG, Schagina LV. Surfactin activity depends on the membrane dipole potential. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:15092-15097. [PMID: 20828112 DOI: 10.1021/la102691y] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
The effect of dipole modifying agents phloretin and RH 421 on the membrane conductance induced by surfactin, a lipopeptide antibiotic from Bacillus subtilis, was studied. Surfactin added on both sides of a bilayer formed from diphytanoylphosphocholine in 1 M KCl (pH 6.5) leads to the formation of voltage-independent channels of different conductance levels. The conductance of different states of SA channels varies from tens of picosiemens for small pores up to tens of nanosiemens for large ones. Small channels demonstrate pronounced cationic selectivity, whereas large ones practically lose their K(+)/Cl(-) selectivity, most probably because of their large effective radii. The addition of phloretin to the bilayer bathing solution, the agent known to decrease the membrane dipole potential, results in a decrease in the surfactin-induced membrane conductance. At the same time, increasing the membrane dipole potential because of the introduction of RH 421 leads to a rise in the steady-state conductance. Increasing dipole potential is accompanied by increases in both the number of open channels and their conductance. The observed changes in the channel-forming activity of surfactin might be caused by varying the partition coefficient of lipopeptide between the lipid and aqueous phases.
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Affiliation(s)
- Olga S Ostroumova
- Institute of Cytology of the Russian Academy of Sciences, St. Petersburg 194064, Russia.
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41
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Orsi M, Michel J, Essex JW. Coarse-grain modelling of DMPC and DOPC lipid bilayers. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2010; 22:155106. [PMID: 21389551 DOI: 10.1088/0953-8984/22/15/155106] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Our recently developed coarse-grain model for dimyristoylphosphatidylcholine (DMPC) has been improved and extended to dioleylphosphatidylcholine (DOPC), a more typical constituent of real biological membranes. Single-component DMPC and DOPC bilayers have been simulated using microsecond-long molecular dynamics. We investigated properties that are difficult or impossible to access experimentally, such as the pressure distribution, the spontaneous curvature and the diffusion pattern of individual lipid molecules. Moreover, we studied the dipole potential, a basic physical feature of paramount biological importance that cannot be currently modelled by other coarse-grain approaches. In fact, a complete representation of the system electrostatics and a realistic description of the water component make our method unique amongst the existing coarse-grain membrane models. The spontaneous permeation of water, a phenomenon out of reach of standard atomistic models, was also observed and quantified; this was possible thanks to the efficiency of our model, which is about two orders of magnitude less computationally expensive than atomic-level counterparts. Results are generally in good agreement with the literature data. Further model extensions and future applications are proposed.
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Affiliation(s)
- Mario Orsi
- School of Chemistry, University of Southampton, Southampton SO17 1BJ, UK
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42
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Przybylo M, Borowik T, Langner M. Fluorescence Techniques for Determination of the Membrane Potentials in High Throughput Screening. J Fluoresc 2010; 20:1139-57. [DOI: 10.1007/s10895-010-0665-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2010] [Accepted: 04/05/2010] [Indexed: 01/14/2023]
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43
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Boggara MB, Krishnamoorti R. Partitioning of nonsteroidal antiinflammatory drugs in lipid membranes: a molecular dynamics simulation study. Biophys J 2010; 98:586-95. [PMID: 20159155 PMCID: PMC2820636 DOI: 10.1016/j.bpj.2009.10.046] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2009] [Revised: 10/13/2009] [Accepted: 10/16/2009] [Indexed: 02/02/2023] Open
Abstract
Using the potential of mean constrained force method, molecular dynamics simulations with atomistic details were performed to examine the partitioning and nature of interactions of two nonsteroidal antiinflammatory drugs, namely aspirin and ibuprofen, in bilayers of dipalmitoylphosphatidylcholine. Two charge states (neutral and anionic) of the drugs were simulated to understand the effect of protonation or pH on drug partitioning. Both drugs, irrespective of their charge state, were found to have high partition coefficients in the lipid bilayer from water. However, the values and trends of the free energy change and the location of the minima in the bilayer are seen to be influenced by the drug structure and charge state. In the context of the transport of the drugs through the bilayer, the charged forms were found to permeate fully hydrated in contrast to the neutral forms that permeate unhydrated.
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Affiliation(s)
| | - Ramanan Krishnamoorti
- Department of Chemical and Biomolecular Engineering, University of Houston, Houston, Texas
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44
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Alakoskela JM, Vitovic P, Kinnunen PKJ. Screening for the drug-phospholipid interaction: correlation to phospholipidosis. ChemMedChem 2009; 4:1224-51. [PMID: 19551800 DOI: 10.1002/cmdc.200900052] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Phospholipid bilayers represent a complex, anisotropic environment fundamentally different from bulk oil or octanol, for instance. Even "simple" drug association to phospholipid bilayers can only be fully understood if the slab-of-hydrocarbon approach is abandoned and the complex, anisotropic properties of lipid bilayers reflecting the chemical structures and organization of the constituent phospholipids are considered. The interactions of drugs with phospholipids are important in various processes, such as drug absorption, tissue distribution, and subcellular distribution. In addition, drug-lipid interactions may lead to changes in lipid-dependent protein activities, and further, to functional and morphological changes in cells, a prominent example being the phospholipidosis (PLD) induced by cationic amphiphilic drugs. Herein we briefly review drug-lipid interactions in general and the significance of these interactions in PLD in particular. We also focus on a potential causal connection between drug-induced PLD and steatohepatitis, which is induced by some cationic amphiphilic drugs.
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Affiliation(s)
- Juha-Matti Alakoskela
- Division of Biochemistry, Institute of Biomedicine, University of Helsinki, Haartmaninkatu 8, 00014 Helsinki, Finland.
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45
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Cohen A, Shirvan A, Levin G, Grimberg H, Reshef A, Ziv I. From the Gla domain to a novel small-molecule detector of apoptosis. Cell Res 2009; 19:625-37. [DOI: 10.1038/cr.2009.17] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
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46
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Abstract
The electrostatic properties of biological membranes can be described by three parameters: the transmembrane potential, the membrane surface potential, and the membrane dipole potential. The first two are well characterized in terms of their magnitudes and biological effects. The dipole potential, however, is not well characterized. Various methods to measure the membrane dipole potential indirectly yield different values, and there is not even agreement on the source of the membrane dipole moment. This ambiguity impedes investigations into the biological effects of the membrane dipole moment, which should be substantial considering the large interfacial fields with which it is associated. Electrostatic analysis of phosphatidylcholine lipid membranes with the atomic force microscope reveals a repulsive force between the negatively charged probe tips and the zwitterionic lipids. This unexpected interaction has been analyzed quantitatively to reveal that the repulsion is due to a weak external field created by the internal membrane dipole potential. The analysis yields a dipole moment of 1.5 Debye per lipid with a dipole potential of +275 mV for supported phosphatidylcholine membranes. This new ability to quantitatively measure the membrane dipole moment in a noninvasive manner with nanometer scale spatial resolution will be useful in identifying the biological effects of the dipole potential.
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47
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Das R, Klymchenko AS, Duportail G, Mély Y. Excited State Proton Transfer and Solvent Relaxation of a 3-Hydroxyflavone Probe in Lipid Bilayers. J Phys Chem B 2008; 112:11929-35. [DOI: 10.1021/jp804956u] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ranjan Das
- Photophysique des Interactions Biomoléculaires, UMR 7175 du CNRS, Institut Gilbert Laustriat, Faculté de Pharmacie, Université Louis Pasteur, 67401 Illkirch, France, and Department of Chemistry, Bijoy Krishna Girls’ College, Howrah, West Bengal, India
| | - Andrey S. Klymchenko
- Photophysique des Interactions Biomoléculaires, UMR 7175 du CNRS, Institut Gilbert Laustriat, Faculté de Pharmacie, Université Louis Pasteur, 67401 Illkirch, France, and Department of Chemistry, Bijoy Krishna Girls’ College, Howrah, West Bengal, India
| | - Guy Duportail
- Photophysique des Interactions Biomoléculaires, UMR 7175 du CNRS, Institut Gilbert Laustriat, Faculté de Pharmacie, Université Louis Pasteur, 67401 Illkirch, France, and Department of Chemistry, Bijoy Krishna Girls’ College, Howrah, West Bengal, India
| | - Yves Mély
- Photophysique des Interactions Biomoléculaires, UMR 7175 du CNRS, Institut Gilbert Laustriat, Faculté de Pharmacie, Université Louis Pasteur, 67401 Illkirch, France, and Department of Chemistry, Bijoy Krishna Girls’ College, Howrah, West Bengal, India
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48
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Membrane dipole potential of interaction between amyloid protein and phospholipid membranes is dependent on protein aggregation state. ACTA ACUST UNITED AC 2008. [DOI: 10.1016/j.jcice.2008.03.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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49
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Matos PM, Gonçalves S, Santos NC. Interaction of peptides with biomembranes assessed by potential-sensitive fluorescent probes. J Pept Sci 2008; 14:407-15. [PMID: 18189333 DOI: 10.1002/psc.1005] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Peptide-membrane interaction is an important step to be evaluated in a study of the activity and mode of action of several bioactive peptides. A variety of methods are available; however, few of them satisfy the criteria of being sensitive, biocompatible, versatile, easy to perform, and allowing real-time monitoring as the use of potential-sensitive fluorescent probes. Here we review methods for detecting the effects of membrane-active peptides, even those that are not intrinsically fluorescent, on the different types of membrane potentials, with a special emphasis on studies conducted with living cells. FPE is a probe sensitive to surface potential and detects electrostatic interactions at the water-lipid interface. Di-8-ANEPPS is sensitive to dipole potential and detects membrane incorporations. Transmembrane potential changes reveal major membrane destabilizations, such as in pore formation. The combination of the information obtained from the three potential variations can lead to a more elucidative picture of the mechanisms of the interaction of relevant peptides with biomembranes.
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Affiliation(s)
- Pedro M Matos
- Instituto de Medicina Molecular, Faculdade de Medicina da Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028 Lisboa, Portugal
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50
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Rafts making and rafts braking: how plant flavonoids may control membrane heterogeneity. Mol Cell Biochem 2008; 314:65-71. [DOI: 10.1007/s11010-008-9766-9] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2007] [Accepted: 04/07/2008] [Indexed: 10/22/2022]
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