1
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Dommer AC, Rogers MM, Carter-Fenk KA, Wauer NA, Rubio P, Davasam A, Allen HC, Amaro RE. Interfacial Enrichment of Lauric Acid Assisted by Long-Chain Fatty Acids, Acidity and Salinity at Sea Spray Aerosol Surfaces. J Phys Chem A 2024. [PMID: 39106367 DOI: 10.1021/acs.jpca.4c03335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/09/2024]
Abstract
Surfactant monolayers at sea spray aerosol (SSA) surfaces regulate various atmospheric processes including gas transfer, cloud interactions, and radiative properties. Most experimental studies of SSA employ a simplified surfactant mixture of long-chain fatty acids (LCFAs) as a proxy for the sea surface microlayer or SSA surface. However, medium-chain fatty acids (MCFAs) make up nearly 30% of the FA fraction in nascent SSA. Given that LCFA monolayers are easily disrupted upon the introduction of chemical heterogeneity (such as mixed chain lengths), simple FA proxies are unlikely to represent realistic SSA interfaces. Integrating experimental and computational techniques, we characterize the impact that partially soluble MCFAs have on the properties of atmospherically relevant LCFA mixtures. We explore the extent to which the MCFA lauric acid (LA) is surface stabilized by varying acidity, salinity, and monolayer composition. We also discuss the impacts of pH on LCFA-assisted LA retention, where the presence of LCFAs may shift the surface-adsorption equilibria of laurate─the conjugate base─toward higher surface activities. Molecular dynamic simulations suggest a mechanism for the enhanced surface retention of laurate. We conclude that increased FA heterogeneity at SSA surfaces promotes surface activity of soluble FA species, altering monolayer phase behavior and impacting climate-relevant atmospheric processes.
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Affiliation(s)
- Abigail C Dommer
- Department of Molecular Biology, University of California, San Diego, La Jolla, California 92093, United States
| | - Mickey M Rogers
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
- Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | - Kimberly A Carter-Fenk
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Nicholas A Wauer
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, United States
| | - Patiemma Rubio
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, United States
| | - Aakash Davasam
- Department of Molecular Biology, University of California, San Diego, La Jolla, California 92093, United States
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, United States
| | - Heather C Allen
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
| | - Rommie E Amaro
- Department of Molecular Biology, University of California, San Diego, La Jolla, California 92093, United States
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2
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Pem B, Pišonić M, Momčilov M, Crnolatac I, Brkljača Z, Vazdar M, Bakarić D. Protonation of palmitic acid embedded in DPPC lipid bilayers obscures detection of ripple phase by FTIR spectroscopy. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2024; 322:124773. [PMID: 39002469 DOI: 10.1016/j.saa.2024.124773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2024] [Revised: 06/03/2024] [Accepted: 07/02/2024] [Indexed: 07/15/2024]
Abstract
The transformation of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) lipid bilayers from the gel (Lβ') to the fluid (Lα) phase involves an intermediate ripple (Pβ') phase forming a few degrees below the main transition temperature (Tm). While the exact cause of bilayer rippling is still debated, the presence of amphiphilic molecules, pH, and lipid bilayer architecture are all known to influence (pre)transition behavior. In particular, fatty acid chains interact with hydrophobic lipid tails, while the carboxylic groups simultaneously participate in proton transfer with interfacial water in the polar lipid region which is controlled by the pH of the surrounding aqueous medium. The molecular-level variations in the DPPC ripple phase in the presence of 2% palmitic acid (PA) were studied at pH levels 4.0, 7.3, and 9.1, where PA is fully protonated, partially protonated, or fully deprotonated. Bilayer thermotropic behavior was investigated by differential scanning calorimetry (DSC) and Fourier-transform infrared (FTIR) spectroscopy which agreed in their characterization of (pre)transition at pH of 9.1, but not at pH 4.0 and especially not at 7.3. Owing to the different insertion depths of protonated and deprotonated PA, along with the ability of protonated PA to undergo flip-flop in the bilayer, these two forms of PA show a different hydration pattern in the interfacial water layer. Finally, these results demonstrated the hitherto undiscovered potential of FTIR spectroscopy in the detection of the events occurring at the surface of lipid bilayers that obscure the low-cooperativity phase transition explored in this work.
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Affiliation(s)
- Barbara Pem
- Division for Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička 54, 10000 Zagreb, Croatia
| | - Marina Pišonić
- Division of Analytical Chemistry, Department of Chemistry, Faculty of Science, University of Zagreb, Horvatovac 102a, 10000 Zagreb, Croatia
| | - Marina Momčilov
- Division of Analytical Chemistry, Department of Chemistry, Faculty of Science, University of Zagreb, Horvatovac 102a, 10000 Zagreb, Croatia
| | - Ivo Crnolatac
- Division for Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička 54, 10000 Zagreb, Croatia
| | - Zlatko Brkljača
- Division for Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička 54, 10000 Zagreb, Croatia
| | - Mario Vazdar
- Department of Mathematics, Informatics, and Cybernetics, University of Chemistry and Technology, Technická 5, 16628 Prague, Czech Republic
| | - Danijela Bakarić
- Division for Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička 54, 10000 Zagreb, Croatia.
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3
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Mills KR, Misra J, Torabifard H. Allosteric Modulation of the YAP/TAZ-TEAD Interaction by Palmitoylation and Small-Molecule Inhibitors. J Phys Chem B 2024; 128:3795-3806. [PMID: 38606592 DOI: 10.1021/acs.jpcb.3c07073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/13/2024]
Abstract
The Hippo signaling pathway is a highly conserved signaling network that plays a central role in regulating cellular growth, proliferation, and organ size. This pathway consists of a kinase cascade that integrates various upstream signals to control the activation or inactivation of YAP/TAZ proteins. Phosphorylated YAP/TAZ is sequestered in the cytoplasm; however, when the Hippo pathway is deactivated, it translocates into the nucleus, where it associates with TEAD transcription factors. This partnership is instrumental in regulating the transcription of progrowth and antiapoptotic genes. Thus, in many cancers, aberrantly hyperactivated YAP/TAZ promotes oncogenesis by contributing to cancer cell proliferation, metastasis, and therapy resistance. Because YAP and TAZ exert their oncogenic effects by binding with TEAD, it is critical to understand this key interaction to develop cancer therapeutics. Previous research has indicated that TEAD undergoes autopalmitoylation at a conserved cysteine, and small molecules that inhibit TEAD palmitoylation disrupt effective YAP/TAZ binding. However, how exactly palmitoylation contributes to YAP/TAZ-TEAD interactions and how the TEAD palmitoylation inhibitors disrupt this interaction remains unknown. Utilizing molecular dynamics simulations, our investigation not only provides detailed atomistic insight into the YAP/TAZ-TEAD dynamics but also unveils that the inhibitor studied influences the binding of YAP and TAZ to TEAD in distinct manners. This discovery has significant implications for the design and deployment of future molecular interventions targeting this interaction.
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Affiliation(s)
- Kira R Mills
- Department of Chemistry & Biochemistry, The University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Jyoti Misra
- Department of Biological Sciences, The University of Texas at Dallas, Richardson, Texas 75080, United States
| | - Hedieh Torabifard
- Department of Chemistry & Biochemistry, The University of Texas at Dallas, Richardson, Texas 75080, United States
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4
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Gentile R, Modric M, Thiele B, Jaeger KE, Kovacic F, Schott-Verdugo S, Gohlke H. Molecular Mechanisms Underlying Medium-Chain Free Fatty Acid-Regulated Activity of the Phospholipase PlaF from Pseudomonas aeruginosa. JACS AU 2024; 4:958-973. [PMID: 38559719 PMCID: PMC10976570 DOI: 10.1021/jacsau.3c00725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 01/08/2024] [Accepted: 01/09/2024] [Indexed: 04/04/2024]
Abstract
PlaF is a membrane-bound phospholipase A1 from Pseudomonas aeruginosa that is involved in remodeling membrane glycerophospholipids (GPLs) and modulating virulence-associated signaling and metabolic pathways. Previously, we identified the role of medium-chain free fatty acids (FFAs) in inhibiting PlaF activity and promoting homodimerization, yet the underlying molecular mechanism remained elusive. Here, we used unbiased and biased molecular dynamics simulations and free energy computations to assess how PlaF interacts with FFAs localized in the water milieu surrounding the bilayer or within the bilayer and how these interactions regulate PlaF activity. Medium-chain FFAs localized in the upper bilayer leaflet can stabilize inactive dimeric PlaF, likely through interactions with charged surface residues, as has been experimentally validated. Potential of mean force (PMF) computations indicate that membrane-bound FFAs may facilitate the activation of monomeric PlaF by lowering the activation barrier for changing into a tilted, active configuration. We estimated that the coupled equilibria of PlaF monomerization-dimerization and tilting at the physiological concentration of PlaF lead to the majority of PlaF forming inactive dimers when in a cell membrane loaded with decanoic acid (C10). This is in agreement with a suggested in vivo product feedback loop and gas chromatography-mass spectrometry profiling results, indicating that PlaF catalyzes the release of C10 from P. aeruginosa membranes. Additionally, we found that C10 in the water milieu can access the catalytic site of active monomeric PlaF, contributing to the competitive component of C10-mediated PlaF inhibition. Our study provides mechanistic insights into how medium-chain FFAs may regulate the activity of PlaF, a potential bacterial drug target.
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Affiliation(s)
- Rocco Gentile
- Institute
for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany
| | - Matea Modric
- Institute
of Molecular Enzyme Technology, Heinrich
Heine University Düsseldorf, Forschungszentrum Jülich
GmbH, 52425 Jülich, Germany
| | - Björn Thiele
- Institute
of Bio- and Geosciences (IBG-2: Plant Sciences and IBG-3: Agrosphere), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Karl-Erich Jaeger
- Institute
of Molecular Enzyme Technology, Heinrich
Heine University Düsseldorf, Forschungszentrum Jülich
GmbH, 52425 Jülich, Germany
- Institute
of Bio- and Geosciences (IBG-1: Biotechnology), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Filip Kovacic
- Institute
of Molecular Enzyme Technology, Heinrich
Heine University Düsseldorf, Forschungszentrum Jülich
GmbH, 52425 Jülich, Germany
| | - Stephan Schott-Verdugo
- Institute
of Bio- and Geosciences (IBG-4: Bioinformatics), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Holger Gohlke
- Institute
for Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany
- Institute
of Bio- and Geosciences (IBG-4: Bioinformatics), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
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5
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Baker S, Desai A, Dinh T, Richards MP. Divergent Reactivity of Hemoglobin Isoforms α 2Aβ 2 and α 2Dβ 2 from Meleagris gallopavo in Native and Fatty Acid-Modified States. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:19717-19726. [PMID: 38029278 DOI: 10.1021/acs.jafc.3c05601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2023]
Abstract
Meleagris gallopavo (turkey) coexpresses distinct hemoglobin (Hb) isoforms, Hb α2Aβ2 (HbA) and α2Dβ2 (HbD), at a ratio of ∼3:1 (HbA:HbD). Herein, the reactivities of HbA and HbD were investigated in their native and free fatty acid (FFA)-modified states. Results indicated that HbD displays elevated autoxidation (kox) and an increased propensity to oxidize lipids in its reduced (oxy) and oxidized (met) forms. Interestingly, metHbD displayed less heme-globin cross-linking compared to HbA. Regarding FFA-modified Hb, we found that an FFA mixture and linoleic acid (LA) produced a bis-histidyl ferric (Bis-His) Hb species, decreasing the ability of Hb to oxidize lipids. Using molecular docking, we found LA to hydrogen bond with β Arg C6, found at the α1β2 interface, but the extent of Bis-His formation differs between HbA and HbD. Our findings suggest HbA displays elevated oxidative stability compared to HbD and that FFA may act as allosteric effectors of metHb.
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Affiliation(s)
- Sean Baker
- Department of Food Science, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Akash Desai
- Department of Animal & Dairy Sciences, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
| | - Thu Dinh
- Department of Animal and Dairy Sciences, Mississippi State University, Starkville, Mississippi 39762, United States
| | - Mark P Richards
- Department of Food Science, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
- Department of Animal & Dairy Sciences, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States
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6
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Pem B, Brkljača Z, Philippe A, Schaumann GE, Vazdar M, Bakarić D. FTIR spectroscopy and molecular level insight of diluted aqueous solutions of acetic acid. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2023; 302:123135. [PMID: 37454436 DOI: 10.1016/j.saa.2023.123135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 06/27/2023] [Accepted: 07/10/2023] [Indexed: 07/18/2023]
Abstract
Aqueous solutions of acetic acid (AA) have been intensively explored for decades with a particular attention addressed to the hydrogen bond network generated by COOH group at different concentrations. In majority of studies conducted so far the envelope originated from νCO is decomposed into two bands assigned to differently hydrated monomers: the one presumably to AA···H2O, and another one to AA···(H2O)2. In order to examine if species other than the mentioned monomers produce this spectral signature, we performed computational and FTIR spectroscopic study of AA in aqueous solutions. Dilute solutions of deuterated acetic acid (CD3COOD) in D2O and in C2Cl4 as a reference were prepared (c0 = 0.001, 0.01 and 0.1 mol dm-3) as well as of deuterated sodium acetate (CD3COONa) in D2O. CD3COOD in 0.1 mol dm-3 solution in D2O displays a feature that separated in two signals with maxima at 1706 cm-1 and 1687 cm-1. A combined DFT and molecular dynamics study performed in this work showed the assignation of those spectral bands to be a more complex problem than previously thought, with syn-anti isomerism and hydration contributing to the experimentally observed broad νCO envelope.
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Affiliation(s)
- Barbara Pem
- Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička 54, 10000 Zagreb, Croatia
| | - Zlatko Brkljača
- Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička 54, 10000 Zagreb, Croatia; Selvita d.o.o. Prilaz baruna Filipovića 29, 10000 Zagreb, Croatia
| | - Allan Philippe
- University of Koblenz-Landau, iES Landau-Institute for Environmental Sciences, Group of Environmental and Soil Chemistry, Fortstraße 7, D-76829 Landau, Germany
| | - Gabriele E Schaumann
- University of Koblenz-Landau, iES Landau-Institute for Environmental Sciences, Group of Environmental and Soil Chemistry, Fortstraße 7, D-76829 Landau, Germany
| | - Mario Vazdar
- Department of Mathematics, Informatics and Cybernetics, University of Chemistry and Technology, 166 28 Prague, Czech Republic
| | - Danijela Bakarić
- Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička 54, 10000 Zagreb, Croatia; University of Koblenz-Landau, iES Landau-Institute for Environmental Sciences, Group of Environmental and Soil Chemistry, Fortstraße 7, D-76829 Landau, Germany.
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7
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Davoudi S, Raemdonck K, Braeckmans K, Ghysels A. Capric Acid and Myristic Acid Permeability Enhancers in Curved Liposome Membranes. J Chem Inf Model 2023; 63:6789-6806. [PMID: 37917127 DOI: 10.1021/acs.jcim.3c00936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2023]
Abstract
Liposomes are considered as advanced drug delivery systems for cancer treatment. A generation of pH-sensitive liposomes is being developed that use fatty acids (FAs) as a trigger for drug release in tumor tissues. However, FAs are also known to enhance permeability, and it is unclear whether FAs in liposomes may cause drug leakage or premature drug release. The passive permeability of the drug through the membrane of the liposome is thus a crucial factor for timely drug delivery. To investigate how the curvature and lipid composition of liposomes affect their passive permeability, coarse-grained molecular dynamics were performed. The permeability was determined with a counting method. Flat bilayers and three liposomes with varying diameters were studied, which had varying lipid compositions of dipalmitoylphosphatidylcholine, cholesterol, and deprotonated or neutral saturated FAs. The investigated permeants were water and two other small permeants, which have different free energy profiles (solubility) across the membrane. First, for the curvature effect, our results showed that curvature increases the water permeability by reducing the membrane thickness. The permeability increase for water is about a factor of 1.7 for the most curved membranes. However, a high curvature decreases permeability for permeants with free energy profiles that are a mix of wells and barriers in the headgroup region of the membrane. Importantly, the type of experimental setup is expected to play a dominant role in the permeability value, i.e., whether permeants are escaping or entering the liposomes. Second, for the composition effect, FAs decrease both the area per lipid (APL) and the membrane thickness, resulting in permeability increases of up to 55%. Cholesterol has a similar effect on the APL but has the opposite impact on membrane thickness and permeability. Therefore, FAs and cholesterol have opposing effects on permeability, with cholesterol's effect being slightly stronger in our simulated bilayers. As all permeability values were well within a factor of 2, and with liposomes usually being larger and less curved in experimental applications, it can be concluded that the passive drug release from a pH-sensitive liposome does not seem to be significantly affected by the presence of FAs.
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Affiliation(s)
- Samaneh Davoudi
- IBiTech─BioMMedA Group, Ghent University, Corneel Heymanslaan 10, Block B-Entrance 36, 9000 Gent, Belgium
| | - Koen Raemdonck
- Ghent Research Group on Nanomedicines, Laboratory for General Biochemistry and Physical Pharmacy, Ghent University, Ottergemsesteenweg 460, 9000 Gent, Belgium
| | - Kevin Braeckmans
- Bio-Photonic Imaging Group, Laboratory for General Biochemistry and Physical Pharmacy, Ghent University, Ottergemsesteenweg 460, 9000 Gent, Belgium
| | - An Ghysels
- IBiTech─BioMMedA Group, Ghent University, Corneel Heymanslaan 10, Block B-Entrance 36, 9000 Gent, Belgium
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8
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Knyazev DG, Silverstein TP, Brescia S, Maznichenko A, Pohl P. A New Theory about Interfacial Proton Diffusion Revisited: The Commonly Accepted Laws of Electrostatics and Diffusion Prevail. Biomolecules 2023; 13:1641. [PMID: 38002323 PMCID: PMC10669390 DOI: 10.3390/biom13111641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 11/02/2023] [Accepted: 11/07/2023] [Indexed: 11/26/2023] Open
Abstract
The high propensity of protons to stay at interfaces has attracted much attention over the decades. It enables long-range interfacial proton diffusion without relying on titratable residues or electrostatic attraction. As a result, various phenomena manifest themselves, ranging from spillover in material sciences to local proton circuits between proton pumps and ATP synthases in bioenergetics. In an attempt to replace all existing theoretical and experimental insight into the origin of protons' preference for interfaces, TELP, the "Transmembrane Electrostatically-Localized Protons" hypothesis, has been proposed. The TELP hypothesis envisions static H+ and OH- layers on opposite sides of interfaces that are up to 75 µm thick. Yet, the separation at which the electrostatic interaction between two elementary charges is comparable in magnitude to the thermal energy is more than two orders of magnitude smaller and, as a result, the H+ and OH- layers cannot mutually stabilize each other, rendering proton accumulation at the interface energetically unfavorable. We show that (i) the law of electroneutrality, (ii) Fick's law of diffusion, and (iii) Coulomb's law prevail. Using them does not hinder but helps to interpret previously published experimental results, and also helps us understand the high entropy release barrier enabling long-range proton diffusion along the membrane surface.
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Affiliation(s)
- Denis G. Knyazev
- Institute of Biophysics, Johannes Kepler University, 4020 Linz, Austria; (D.G.K.); (S.B.); (A.M.)
| | | | - Stefania Brescia
- Institute of Biophysics, Johannes Kepler University, 4020 Linz, Austria; (D.G.K.); (S.B.); (A.M.)
| | - Anna Maznichenko
- Institute of Biophysics, Johannes Kepler University, 4020 Linz, Austria; (D.G.K.); (S.B.); (A.M.)
| | - Peter Pohl
- Institute of Biophysics, Johannes Kepler University, 4020 Linz, Austria; (D.G.K.); (S.B.); (A.M.)
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9
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Rokitskaya TI, Khailova LS, Korshunova GA, Antonenko YN. Efficiency of mitochondrial uncoupling by modified butyltriphenylphosphonium cations and fatty acids correlates with lipophilicity of cations: Protonophoric vs leakage mechanisms. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2023; 1865:184183. [PMID: 37286154 DOI: 10.1016/j.bbamem.2023.184183] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Revised: 05/19/2023] [Accepted: 05/31/2023] [Indexed: 06/09/2023]
Abstract
In order to determine the share of protonophoric activity in the uncoupling action of lipophilic cations a number of analogues of butyltriphenylphosphonium with substitutions in phenyl rings (C4TPP-X) were studied on isolated rat liver mitochondria and model lipid membranes. An increase in the rate of respiration and a decrease in the membrane potential of isolated mitochondria were observed for all the studied cations, the efficiency of these processes was significantly enhanced in the presence of fatty acids and correlated with the octanol-water partition coefficient of the cations. The ability of C4TPP-X cations to induce proton transport across the lipid membrane of liposomes loaded with a pH-sensitive fluorescent dye increased also with their lipophilicity and depended on the presence of palmitic acid in the liposome membrane. Of all the cations, only butyl[tri(3,5-dimethylphenyl)]phosphonium (C4TPP-diMe) was able to induce proton transport by the mechanism of formation of a cation-fatty acid ion pair on planar bilayer lipid membranes and liposomes. The rate of oxygen consumption by mitochondria in the presence of C4TPP-diMe increased to the maximum values corresponding to conventional uncouplers; for all other cations the maximum uncoupling rates were significantly lower. We assume that the studied cations of the C4TPP-X series, with the exception of C4TPP-diMe at low concentrations, cause nonspecific leak of ions through lipid model and biological membranes which is significantly enhanced in the presence of fatty acids.
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Affiliation(s)
- Tatyana I Rokitskaya
- 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
| | - Galina A Korshunova
- 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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10
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Kreiter J, Škulj S, Brkljača Z, Bardakji S, Vazdar M, Pohl EE. FA Sliding as the Mechanism for the ANT1-Mediated Fatty Acid Anion Transport in Lipid Bilayers. Int J Mol Sci 2023; 24:13701. [PMID: 37762012 PMCID: PMC10531397 DOI: 10.3390/ijms241813701] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 08/27/2023] [Accepted: 08/29/2023] [Indexed: 09/29/2023] Open
Abstract
Mitochondrial adenine nucleotide translocase (ANT) exchanges ADP for ATP to maintain energy production in the cell. Its protonophoric function in the presence of long-chain fatty acids (FA) is also recognized. Our previous results imply that proton/FA transport can be best described with the FA cycling model, in which protonated FA transports the proton to the mitochondrial matrix. The mechanism by which ANT1 transports FA anions back to the intermembrane space remains unclear. Using a combined approach involving measurements of the current through the planar lipid bilayers reconstituted with ANT1, site-directed mutagenesis and molecular dynamics simulations, we show that the FA anion is first attracted by positively charged arginines or lysines on the matrix side of ANT1 before moving along the positively charged protein-lipid interface and binding to R79, where it is protonated. We show that R79 is also critical for the competitive binding of ANT1 substrates (ADP and ATP) and inhibitors (carboxyatractyloside and bongkrekic acid). The binding sites are well conserved in mitochondrial SLC25 members, suggesting a general mechanism for transporting FA anions across the inner mitochondrial membrane.
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Affiliation(s)
- Jürgen Kreiter
- Institute of Physiology, Pathophysiology, and Biophysics, Department of Biomedical Sciences, University of Veterinary Medicine, 1210 Vienna, Austria; (J.K.); (S.Š.); (S.B.)
| | - Sanja Škulj
- Institute of Physiology, Pathophysiology, and Biophysics, Department of Biomedical Sciences, University of Veterinary Medicine, 1210 Vienna, Austria; (J.K.); (S.Š.); (S.B.)
| | - Zlatko Brkljača
- Division of Organic Chemistry and Biochemistry, Rudjer Bošković Institute, 10000 Zagreb, Croatia;
| | - Sarah Bardakji
- Institute of Physiology, Pathophysiology, and Biophysics, Department of Biomedical Sciences, University of Veterinary Medicine, 1210 Vienna, Austria; (J.K.); (S.Š.); (S.B.)
| | - Mario Vazdar
- Department of Mathematics, Informatics, and Cybernetics, University of Chemistry and Technology, 166 28 Prague, Czech Republic
| | - Elena E. Pohl
- Institute of Physiology, Pathophysiology, and Biophysics, Department of Biomedical Sciences, University of Veterinary Medicine, 1210 Vienna, Austria; (J.K.); (S.Š.); (S.B.)
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11
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Venianakis T, Siskos MG, Papamokos G, Gerothanassis IP. Structural Studies of Monounsaturated and ω-3 Polyunsaturated Free Fatty Acids in Solution with the Combined Use οf NMR and DFT Calculations-Comparison with the Liquid State. Molecules 2023; 28:6144. [PMID: 37630396 PMCID: PMC10459368 DOI: 10.3390/molecules28166144] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2023] [Revised: 08/14/2023] [Accepted: 08/18/2023] [Indexed: 08/27/2023] Open
Abstract
Molecular structures, in chloroform and DMSO solution, of the free fatty acids (FFAs) caproleic acid, oleic acid, α-linolenic acid, eicosapentanoic acid (EPA) and docosahexaenoic acid (DHA) are reported with the combined use of NMR and DFT calculations. Variable temperature and concentration chemical shifts of the COOH protons, transient 1D NOE experiments and DFT calculations demonstrate the major contribution of low molecular weight aggregates of dimerized fatty acids through intermolecular hydrogen bond interactions of the carboxylic groups, with parallel and antiparallel interdigitated structures even at the low concentration of 20 mM in CDCl3. For the dimeric DHA, a structural model of an intermolecular hydrogen bond through carboxylic groups and an intermolecular hydrogen bond between the carboxylic group of one molecule and the ω-3 double bond of a second molecule is shown to play a role. In DMSO-d6 solution, NMR and DFT studies show that the carboxylic groups form strong intermolecular hydrogen bond interactions with a single discrete solvation molecule of DMSO. These solvation species form parallel and antiparallel interdigitated structures of low molecular weight, as in chloroform solution. This structural motif, therefore, is an intrinsic property of the FFAs, which is not strongly affected by the length and degree of unsaturation of the chain and the hydrogen bond ability of the solvent.
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Affiliation(s)
| | | | - George Papamokos
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece; (T.V.); (M.G.S.)
| | - Ioannis P. Gerothanassis
- Section of Organic Chemistry and Biochemistry, Department of Chemistry, University of Ioannina, 45110 Ioannina, Greece; (T.V.); (M.G.S.)
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12
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Sanders JM, Coscia BJ, Fonari A, Misra M, Mileo PGM, Giesen DJ, Browning AR, Halls MD. Exploring the Effects of Wetting and Free Fatty Acid Deposition on an Atomistic Hair Fiber Surface Model Incorporating Keratin-Associated Protein 5-1. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2023; 39:5263-5274. [PMID: 37014946 DOI: 10.1021/acs.langmuir.2c03063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The complex development of cosmetic and medical formulations relies on an ever-growing accuracy of predictive models of hair surfaces. Hitherto, modeling efforts have focused on the description of 18-methyl eicosanoic acid (18-MEA), the primary fatty acid covalently attached to the hair surface, without explicit modeling of the protein layer. Herein, the molecular details of the outermost surface of the human hair fiber surface, also called the F-layer, were studied using molecular dynamics (MD) simulations. The F-layer is composed primarily of keratin-associated proteins KAP5 and KAP10, which are decorated with 18-MEA on the outer surface of a hair fiber. In our molecular model, we incorporated KAP5-1 and evaluated the surface properties of 18-MEA through MD simulations, resulting in 18-MEA surface density, layer thickness, and tilt angles in agreement with previous experimental and computational studies. Subsequent models with reduced 18-MEA surface density were also generated to mimic damaged hair surfaces. Response to wetting of virgin and damaged hair showed rearrangement of 18-MEA on the surface, allowing for water penetration into the protein layer. To demonstrate a potential use case for these atomistic models, we deposited naturally occurring fatty acids and measured 18-MEA's response in both dry and wet conditions. As fatty acids are often incorporated in shampoo formulations, this work demonstrates the ability to model the adsorption of ingredients on hair surfaces. This study illustrates, for the first time, the complex behavior of a realistic F-layer at the molecular level and opens up the possibility of studying the adsorption behavior of larger, more complex molecules and formulations.
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Affiliation(s)
| | | | - Alexandr Fonari
- Schrödinger, LLC, New York, New York 10036-4041, United States
| | - Mayank Misra
- Schrödinger, LLC, New York, New York 10036-4041, United States
| | | | - David J Giesen
- Schrödinger, LLC, New York, New York 10036-4041, United States
| | | | - Mathew D Halls
- Schrödinger, LLC, New York, New York 10036-4041, United States
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13
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Quek WP, Ong YH, Yap MKK, Lee YY, Karim NAA, Chan ES. A comparative study of the oxidative stability and the formation of monochloropropanediol esters (MCPDE) and glycidyl esters (GE) between physically and chemically refined palm olein during repeated deep-frying. Food Control 2023. [DOI: 10.1016/j.foodcont.2023.109737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2023]
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14
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Cui S, Ye J. A protein-lipid complex that detoxifies free fatty acids. Bioessays 2023; 45:e2200210. [PMID: 36585363 PMCID: PMC9974861 DOI: 10.1002/bies.202200210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 12/16/2022] [Accepted: 12/19/2022] [Indexed: 01/01/2023]
Abstract
Fatty acids (FAs) are well known to serve as substrates for reactions that provide cells with membranes and energy. In contrast to these metabolic reactions, the physiological importance of FAs themselves known as free FAs (FFAs) in cells remains obscure. Since accumulation of FFAs in cells is toxic, cells must develop mechanisms to detoxify FFAs. One such mechanism is to sequester free polyunsaturated FAs (PUFAs) into a droplet-like structure assembled by Fas-Associated Factor 1 (FAF1), a cytosolic protein. This sequestration limits access of PUFAs to Fe2+ , thereby preventing Fe2+ -catalyzed PUFA peroxidation. Consequently, assembly of the FAF1-FFA complex is critical to protect cells from ferroptosis, a cell death pathway triggered by PUFA peroxidation. The observations that free PUFAs in cytosol are not randomly diffused but rather sequestered into a membraneless complex should open new directions to explore signaling pathways by which FFAs regulate cellular physiology.
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Affiliation(s)
- Shaojie Cui
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Jin Ye
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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15
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Seo H, Jeon L, Kwon J, Lee H. High-Precision Synthesis of RNA-Loaded Lipid Nanoparticles for Biomedical Applications. Adv Healthc Mater 2023; 12:e2203033. [PMID: 36737864 DOI: 10.1002/adhm.202203033] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 01/26/2023] [Indexed: 02/05/2023]
Abstract
The recent development of RNA-based therapeutics in delivering nucleic acids for gene editing and regulating protein translation has led to the effective treatment of various diseases including cancer, inflammatory and genetic disorder, as well as infectious diseases. Among these, lipid nanoparticles (LNP) have emerged as a promising platform for RNA delivery and have shed light by resolving the inherent instability issues of naked RNA and thereby enhancing the therapeutic potency. These LNP consisting of ionizable lipid, helper lipid, cholesterol, and poly(ethylene glycol)-anchored lipid can stably enclose RNA and help them release into the cells' cytosol. Herein, the significant progress made in LNP research starting from the LNP constituents, formulation, and their diverse applications is summarized first. Moreover, the microfluidic methodologies which allow precise assembly of these newly developed constituents to achieve LNP with controllable composition and size, high encapsulation efficiency as well as scalable production are highlighted. Furthermore, a short discussion on current challenges as well as an outlook will be given on emerging approaches to resolving these issues.
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Affiliation(s)
- Hanjin Seo
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk, 37673, Korea
| | - Leekang Jeon
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk, 37673, Korea
| | - Jaeyeong Kwon
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk, 37673, Korea
| | - Hyomin Lee
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk, 37673, Korea
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16
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Quek WP, Ong YH, Yap MKK, Lee YY, Ab Karim NA, Chew CL, Chan ES. The effects of quality changes in vegetable oils on the formation and absorption of monochloropropanediol esters (MCPDE) and glycidyl esters (GE) during deep-frying of potato chips. Food Control 2023. [DOI: 10.1016/j.foodcont.2023.109699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
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17
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Hashiba K, Sato Y, Taguchi M, Sakamoto S, Otsu A, Maeda Y, Shishido T, Murakawa M, Okazaki A, Harashima H. Branching Ionizable Lipids Can Enhance the Stability, Fusogenicity, and Functional Delivery of mRNA. SMALL SCIENCE 2022. [DOI: 10.1002/smsc.202200071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Affiliation(s)
- Kazuki Hashiba
- Nucleic Acid Medicine Business Division Nitto Denko Corporation 1-1-2, Shimohozumi Ibaraki Osaka 567-8680 Japan
| | - Yusuke Sato
- Laboratory for Molecular Design of Pharmaceutics, Faculty of Pharmaceutical Sciences Hokkaido University Kita-12, Nishi-6 Kita-Ku Sapporo 060-0812 Japan
| | - Masamitsu Taguchi
- Nucleic Acid Medicine Business Division Nitto Denko Corporation 1-1-2, Shimohozumi Ibaraki Osaka 567-8680 Japan
| | - Sachiko Sakamoto
- Nucleic Acid Medicine Business Division Nitto Denko Corporation 1-1-2, Shimohozumi Ibaraki Osaka 567-8680 Japan
| | - Ayaka Otsu
- Nucleic Acid Medicine Business Division Nitto Denko Corporation 1-1-2, Shimohozumi Ibaraki Osaka 567-8680 Japan
| | - Yoshiki Maeda
- Nucleic Acid Medicine Business Division Nitto Denko Corporation 1-1-2, Shimohozumi Ibaraki Osaka 567-8680 Japan
| | - Takuya Shishido
- Nucleic Acid Medicine Business Division Nitto Denko Corporation 1-1-2, Shimohozumi Ibaraki Osaka 567-8680 Japan
| | - Masao Murakawa
- Nucleic Acid Medicine Business Division Nitto Denko Corporation 1-1-2, Shimohozumi Ibaraki Osaka 567-8680 Japan
| | - Arimichi Okazaki
- Nucleic Acid Medicine Business Division Nitto Denko Corporation 1-1-2, Shimohozumi Ibaraki Osaka 567-8680 Japan
| | - Hideyoshi Harashima
- Laboratory for Molecular Design of Pharmaceutics, Faculty of Pharmaceutical Sciences Hokkaido University Kita-12, Nishi-6 Kita-Ku Sapporo 060-0812 Japan
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18
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Yeo S, Kim MJ, Shim YK, Yoon I, Lee WK. Solid Lipid Nanoparticles of Curcumin Designed for Enhanced Bioavailability and Anticancer Efficiency. ACS OMEGA 2022; 7:35875-35884. [PMID: 36249382 PMCID: PMC9558702 DOI: 10.1021/acsomega.2c04407] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 09/08/2022] [Indexed: 05/23/2023]
Abstract
Curcumin (Cur) has anticancer properties but exhibits poor aqueous solubility, permeability, and photostability. In this study, we aimed to develop a solid lipid nanoparticle (SLN) system to enhance Cur bioavailability. The characteristics of Cur-loaded SLNs prepared by sonication were evaluated using UV-vis and Fourier transform infrared spectroscopy. The mean particle size of the stearic acid-based, lauric acid-based, and palmitic acid-based SLNs was 14.70-149.30, 502.83, and 469.53 nm, respectively. The chemical interactions between Cur and lipids involved hydrogen bonding and van der Waals forces. The formulations with high van der Waals forces might produce a neat arrangement between Cur and lipids, leading to a decrease in particle size. The Cur formulations showed enhanced cytotoxicity in HeLa, A549, and CT-26 cells compared with pure Cur. Additionally, the anticancer effect is dependent on particle size and the type of cell line. Therefore, Cur-loaded SLNs have the potential for use in anticancer therapy.
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19
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Gullett JM, Cuypers MG, Grace CR, Pant S, Subramanian C, Tajkhorshid E, Rock CO, White SW. Identification of Structural transitions in bacterial fatty acid binding proteins that permit ligand entry and exit at membranes. J Biol Chem 2022; 298:101676. [PMID: 35122790 PMCID: PMC8892158 DOI: 10.1016/j.jbc.2022.101676] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 01/26/2022] [Accepted: 01/28/2022] [Indexed: 12/31/2022] Open
Abstract
Fatty acid (FA) transfer proteins extract FA from membranes and sequester them to facilitate their movement through the cytosol. Detailed structural information is available for these soluble protein–FA complexes, but the structure of the protein conformation responsible for FA exchange at the membrane is unknown. Staphylococcus aureus FakB1 is a prototypical bacterial FA transfer protein that binds palmitate within a narrow, buried tunnel. Here, we define the conformational change from a “closed” FakB1 state to an “open” state that associates with the membrane and provides a path for entry and egress of the FA. Using NMR spectroscopy, we identified a conformationally flexible dynamic region in FakB1, and X-ray crystallography of FakB1 mutants captured the conformation of the open state. In addition, molecular dynamics simulations show that the new amphipathic α-helix formed in the open state inserts below the phosphate plane of the bilayer to create a diffusion channel for the hydrophobic FA tail to access the hydrocarbon core and place the carboxyl group at the phosphate layer. The membrane binding and catalytic properties of site-directed mutants were consistent with the proposed membrane docked structure predicted by our molecular dynamics simulations. Finally, the structure of the bilayer-associated conformation of FakB1 has local similarities with mammalian FA binding proteins and provides a conceptual framework for how these proteins interact with the membrane to create a diffusion channel from the FA location in the bilayer to the protein interior.
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Affiliation(s)
- Jessica M Gullett
- Departments of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Maxime G Cuypers
- Departments of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Christy R Grace
- Departments of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Shashank Pant
- Theoretical and Computational Biophysics Group, NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology, Department of Biochemistry, and Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Chitra Subramanian
- Departments of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
| | - Emad Tajkhorshid
- Theoretical and Computational Biophysics Group, NIH Center for Macromolecular Modeling and Bioinformatics, Beckman Institute for Advanced Science and Technology, Department of Biochemistry, and Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Charles O Rock
- Departments of Infectious Diseases, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
| | - Stephen W White
- Departments of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
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20
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Joardar A, Pattnaik GP, Chakraborty H. Effect of Phosphatidylethanolamine and Oleic Acid on Membrane Fusion: Phosphatidylethanolamine Circumvents the Classical Stalk Model. J Phys Chem B 2021; 125:13192-13202. [PMID: 34839659 DOI: 10.1021/acs.jpcb.1c08044] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Membrane fusion is one of the most important processes for the survival of eukaryotic cells and entry of enveloped viruses to the host cells. Lipid composition plays a crucial role in the process by modulating the organization and dynamics of the membrane, as well as the structure and conformation of membrane proteins. Phosphatidylethanolamine (PE), a lipid molecule with intrinsic negative curvature, promotes membrane fusion by stabilizing the non-lamellar intermediate structures in the fusion process. Conversely, oleic acid (OA), with intrinsic positive curvature, inhibits membrane fusion. The current study aimed to investigate polyethylene glycol-mediated lipid mixing, content mixing, content leakage, and depth-dependent membrane organization and dynamics, using arrays of steady-state and time-resolved fluorescence techniques, to determine the causative role of PE and OA in membrane fusion. The results demonstrated that the presence of 30 mol % PE in the membrane promotes membrane fusion through a mechanism that circumvents the classical stalk model. On the contrary, membranes containing OA showed reduced rate and extent of fusion, despite following the same mechanism. Collectively, our findings in terms of membrane organization and dynamics indicated a plausible role of PE and OA in membrane fusion.
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Affiliation(s)
- Ankita Joardar
- School of Chemistry, Sambalpur University, Jyoti Vihar, Burla, Odisha 768 019, India
| | | | - Hirak Chakraborty
- School of Chemistry, Sambalpur University, Jyoti Vihar, Burla, Odisha 768 019, India
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21
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Smorygina AS, Golysheva EA, Dzuba SA. Clustering of Stearic Acids in Model Phospholipid Membranes Revealed by Double Electron-Electron Resonance. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:13909-13916. [PMID: 34787421 DOI: 10.1021/acs.langmuir.1c02460] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Free fatty acids play various important roles in biological membranes. Double electron-electron resonance spectroscopy (DEER, also known as PELDOR) of spin-labeled biomolecules is capable of studying magnetic dipole-dipole (d-d) interactions between spin labels at the nanoscale range of distances. Here, DEER is applied to study intermolecular d-d interactions between doxyl-spin-labeled stearic acids (DSA) in gel-phase phospholipid bilayers composed either of an equimolecular mixture of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine and 1,2-dioleoyl-sn-glycero-3-phosphocholine or of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine. DEER data obtained for different DSA concentrations showed that DSA molecules at their concentration in the bilayer χ larger than 0.5 mol % are assembled into lateral lipid-mediated clusters, with a characteristic intermolecular distance of 2 nm. Some evidences were obtained indicating that clusters may consist of "subclusters", alternatively appearing in two opposite leaflets. Conventional electron paramagnetic resonance (EPR) spectra for the gel-phase bilayers showed that for χ larger than 2 mol % the molecules in the clusters stick together, forming oligomers. Room-temperature EPR spectra for the liquid-crystalline phase were found to change noticeably for χ larger than 0.5 mol %, which may indicate the clustering in a liquid-crystalline phase similar to that observed by DEER in the gel phase.
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Affiliation(s)
- Anna S Smorygina
- Institute of Chemical Kinetics and Combustion, Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - Elena A Golysheva
- Institute of Chemical Kinetics and Combustion, Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - Sergei A Dzuba
- Institute of Chemical Kinetics and Combustion, Russian Academy of Sciences, Novosibirsk 630090, Russia
- Department of Physics, Novosibirsk State University, Novosibirsk 630090, Russia
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22
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Ohnari H, Sekiya M, Naru E, Ogura T, Sakata O, Obata Y. Amino Acids and Their N-Acetylated Derivatives Maintain the Skin's Barrier Function. Chem Pharm Bull (Tokyo) 2021; 69:652-660. [PMID: 34193714 DOI: 10.1248/cpb.c21-00152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The hydrocarbon-chain packing structure of intercellular lipids in the stratum corneum (SC) is critical to the skin's barrier function. We previously found that formation of V-shaped ceramide reduces the barrier function of skin. There are few agents, apart from ceramides and fatty acids that can improve the orthorhombic packing (Orth) ratio of the intercellular lipid packing structure. In this study, we investigated agents that directly increase the Orth ratio. We selected an intercellular lipid model consisting of ceramide, cholesterol, and palmitic acid and performed differential scanning calorimetry. We focused on natural moisturizing factor components in the SC, and therefore investigated amino acids and their derivatives. The results of our intercellular lipid model-based study indicate that N-acetyl-L-hydroxyproline (AHYP), remarkably, maintains the lamellar structure. We verified the effect of AHYP on the lamellar structure and hydrocarbon chain packing structure of intercellular lipids using time-resolved X-ray diffraction measurements of human SC. We also determined the direct physicochemical effects of AHYP on the Orth ratio of the hydrocarbon-chain packing structure. Hence, the results of our human SC study suggest that AHYP preserves skin barrier function by maintaining the hydrocarbon-chain packing structure of intercellular lipids via electrostatic repulsion. These findings will facilitate the development of skincare formulation that can maintain the skin's barrier function.
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Affiliation(s)
| | | | - Eiji Naru
- Research and Development Division, KOSÉ Corporation
| | - Taku Ogura
- Research Institute for Science & Technology, Tokyo University of Science
| | - Osamu Sakata
- Research and Development Division, KOSÉ Corporation
| | - Yasuko Obata
- Department of Pharmaceutical Sciences, Hoshi University
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23
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Neuroprotective Potential of Mild Uncoupling in Mitochondria. Pros and Cons. Brain Sci 2021; 11:brainsci11081050. [PMID: 34439669 PMCID: PMC8392724 DOI: 10.3390/brainsci11081050] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 08/03/2021] [Accepted: 08/05/2021] [Indexed: 02/07/2023] Open
Abstract
There has been an explosion of interest in the use of uncouplers of oxidative phosphorylation in mitochondria in the treatment of several pathologies, including neurological ones. In this review, we analyzed all the mechanisms associated with mitochondrial uncoupling and the metabolic and signaling cascades triggered by uncouplers. We provide a full set of positive and negative effects that should be taken into account when using uncouplers in experiments and clinical practice.
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24
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Ibrahim UH, Devnarain N, Omolo CA, Mocktar C, Govender T. Biomimetic pH/lipase dual responsive vitamin-based solid lipid nanoparticles for on-demand delivery of vancomycin. Int J Pharm 2021; 607:120960. [PMID: 34333022 DOI: 10.1016/j.ijpharm.2021.120960] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 07/25/2021] [Accepted: 07/27/2021] [Indexed: 01/12/2023]
Abstract
In this study, ascorbyl tocopherol succinate (ATS) was designed, synthesized and characterized via FT-IR, HR-MS, H1 NMR and C13 NMR, to simultaneously confer biomimetic and dual responsive properties of an antibiotic nanosystem to enhance their antibacterial efficacy and reduce antimicrobial resistance. Therefore, an in silico-aided design (to mimic the natural substrate of bacterial lipase) was employed to demonstrate the binding potential of ATS to lipase (-32.93 kcal/mol binding free energy (ΔGbind) and bacterial efflux pumps blocking potential (NorA ΔGbind: -37.10 kcal/mol, NorB ΔGbind: -34.46 kcal/mol). ATS bound stronger to lipase than the natural substrate (35 times lower Kd value). The vancomycin loaded solid lipid nanoparticles (VM-ATS-SLN) had a hydrodynamic diameter, zeta potential, polydispersity index and entrapment efficiency of 106.9 ± 1.4 nm, -16.5 ± 0.93 mV, 0.11 ± 0.012 and 61.9 ± 1.31%, respectively. In vitro biocompatibility studies revealed VM-ATS-SLN biosafety and non-haemolytic activity. Significant enhancement in VM release was achieved in response to acidified pH and lipase enzyme, compared to controls. VM-ATS-SLN showed enhanced sustained in vitro antibacterial activity for 5 days, 2-fold greater MRSA biofilm growth inhibition and 3.44-fold reduction in bacterial burden in skin infected mice model compared to bare VM. Therefore, ATS shows potential as a novel multifunctional adjuvant for effective and targeted delivery of antibiotics.
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Affiliation(s)
- Usri H Ibrahim
- Discipline of Pharmaceutical Sciences, College of Health Sciences, University of KwaZulu-Natal, Private Bag X54001, Durban, South Africa
| | - Nikita Devnarain
- Discipline of Pharmaceutical Sciences, College of Health Sciences, University of KwaZulu-Natal, Private Bag X54001, Durban, South Africa
| | - Calvin A Omolo
- Discipline of Pharmaceutical Sciences, College of Health Sciences, University of KwaZulu-Natal, Private Bag X54001, Durban, South Africa; United States International University-Africa, School of Pharmacy and Health Sciences, Department of Pharmaceutics, P.O. Box 14634-00800, Nairobi, Kenya.
| | - Chunderika Mocktar
- Discipline of Pharmaceutical Sciences, College of Health Sciences, University of KwaZulu-Natal, Private Bag X54001, Durban, South Africa
| | - Thirumala Govender
- Discipline of Pharmaceutical Sciences, College of Health Sciences, University of KwaZulu-Natal, Private Bag X54001, Durban, South Africa.
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25
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Galassi VV, Wilke N. On the Coupling between Mechanical Properties and Electrostatics in Biological Membranes. MEMBRANES 2021; 11:478. [PMID: 34203412 PMCID: PMC8306103 DOI: 10.3390/membranes11070478] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2021] [Revised: 06/18/2021] [Accepted: 06/22/2021] [Indexed: 12/24/2022]
Abstract
Cell membrane structure is proposed as a lipid matrix with embedded proteins, and thus, their emerging mechanical and electrostatic properties are commanded by lipid behavior and their interconnection with the included and absorbed proteins, cytoskeleton, extracellular matrix and ionic media. Structures formed by lipids are soft, dynamic and viscoelastic, and their properties depend on the lipid composition and on the general conditions, such as temperature, pH, ionic strength and electrostatic potentials. The dielectric constant of the apolar region of the lipid bilayer contrasts with that of the polar region, which also differs from the aqueous milieu, and these changes happen in the nanometer scale. Besides, an important percentage of the lipids are anionic, and the rest are dipoles or higher multipoles, and the polar regions are highly hydrated, with these water molecules forming an active part of the membrane. Therefore, electric fields (both, internal and external) affects membrane thickness, density, tension and curvature, and conversely, mechanical deformations modify membrane electrostatics. As a consequence, interfacial electrostatics appears as a highly important parameter, affecting the membrane properties in general and mechanical features in particular. In this review we focus on the electromechanical behavior of lipid and cell membranes, the physicochemical origin and the biological implications, with emphasis in signal propagation in nerve cells.
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Affiliation(s)
- Vanesa Viviana Galassi
- Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Cuyo, Mendoza M5500, Argentina;
- Instituto Interdisciplinario de Ciencias Básicas (ICB), Universidad Nacional de Cuyo, CONICET, Mendoza M5500, Argentina
| | - Natalia Wilke
- Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba X5000HUA, Argentina
- Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), Universidad Nacional de Córdoba, CONICET, Córdoba X5000HUA, Argentina
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Hayashi K, Sugimura H, Kamei T, Shimanouchi T, Nakamura H, Umakoshi H. Quantitative Determination of Relative Permittivity Based on the Fluorescence Property of Pyrene Derivatives: An Interpretation of Hydrophobicity in Self-Assembled Aggregates of Nonionic Amphiphiles. J Phys Chem B 2021; 125:6192-6200. [PMID: 34077661 DOI: 10.1021/acs.jpcb.1c00170] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Aggregates in aqueous solutions can embed hydrophobic molecules, and their interactions depend on the properties of the aggregates. The electric surface potential, molecular mobility, and gradual hydrophobicity are the properties that regulate the interactions, and it is essential to understand these to quantify the properties. Electric surface potential and molecular mobility are quantified using the zeta potential and NMR measurements. In this study, the quantification of gradual hydrophobicity within the aggregate based on the relative permittivity, also called the dielectric constant, has been estimated from fluorescence spectra of pyrene-dicarboxylic acid conjugates. The localization of the pyrene moiety was modified by conjugation with succinic acid, suberic acid, or dodecanedioic acid, and the conjugates were evaluated in the shallow, middle, and deep regions of the aggregates. Span and Tween surfactants have been employed to prepare these aggregates, because they form various kinds of aggregates such as micelles and vesicles. It was realized that the hydrophobicity gradually increased from the interface to the hydrophobic core. Alternatively, a comparison of hydrophobicity within the aggregates showed no remarkable difference. Moreover, the analyses suggested that there are a few water molecules in the deep region. These results support the idea of the localization of embedded molecules in aggregates.
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Affiliation(s)
- Keita Hayashi
- Department of Chemical Engineering, National Institute of Technology, Nara College, 22 Yata-cho, Yamatokoriyama, Nara 639-1080, Japan
| | - Haruna Sugimura
- Department of Chemical Engineering, National Institute of Technology, Nara College, 22 Yata-cho, Yamatokoriyama, Nara 639-1080, Japan
| | - Toshiyuki Kamei
- Department of Chemical Engineering, National Institute of Technology, Nara College, 22 Yata-cho, Yamatokoriyama, Nara 639-1080, Japan
| | - Toshinori Shimanouchi
- Graduate School of Environmental and Life Science, Okayama University, 3-1-1 Tsushima-Naka, Kita-ku, Okayama 700-8530, Japan
| | - Hidemi Nakamura
- Department of Chemical Engineering, National Institute of Technology, Nara College, 22 Yata-cho, Yamatokoriyama, Nara 639-1080, Japan
| | - Hiroshi Umakoshi
- Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama-cho, Toyonaka, Osaka 560-8531, Japan
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Kreiter J, Rupprecht A, Škulj S, Brkljača Z, Žuna K, Knyazev DG, Bardakji S, Vazdar M, Pohl EE. ANT1 Activation and Inhibition Patterns Support the Fatty Acid Cycling Mechanism for Proton Transport. Int J Mol Sci 2021; 22:ijms22052490. [PMID: 33801254 PMCID: PMC7958136 DOI: 10.3390/ijms22052490] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 02/22/2021] [Accepted: 02/24/2021] [Indexed: 01/26/2023] Open
Abstract
Adenine nucleotide translocase (ANT) is a well-known mitochondrial exchanger of ATP against ADP. In contrast, few studies have shown that ANT also mediates proton transport across the inner mitochondrial membrane. The results of these studies are controversial and lead to different hypotheses about molecular transport mechanisms. We hypothesized that the H+-transport mediated by ANT and uncoupling proteins (UCP) has a similar regulation pattern and can be explained by the fatty acid cycling concept. The reconstitution of purified recombinant ANT1 in the planar lipid bilayers allowed us to measure the membrane current after the direct application of transmembrane potential ΔΨ, which would correspond to the mitochondrial states III and IV. Experimental results reveal that ANT1 does not contribute to a basal proton leak. Instead, it mediates H+ transport only in the presence of long-chain fatty acids (FA), as already known for UCPs. It depends on FA chain length and saturation, implying that FA’s transport is confined to the lipid-protein interface. Purine nucleotides with the preference for ATP and ADP inhibited H+ transport. Specific inhibitors of ATP/ADP transport, carboxyatractyloside or bongkrekic acid, also decreased proton transport. The H+ turnover number was calculated based on ANT1 concentration determined by fluorescence correlation spectroscopy and is equal to 14.6 ± 2.5 s−1. Molecular dynamic simulations revealed a large positively charged area at the protein/lipid interface that might facilitate FA anion’s transport across the membrane. ANT’s dual function—ADP/ATP and H+ transport in the presence of FA—may be important for the regulation of mitochondrial membrane potential and thus for potential-dependent processes in mitochondria. Moreover, the expansion of proton-transport modulating drug targets to ANT1 may improve the therapy of obesity, cancer, steatosis, cardiovascular and neurodegenerative diseases.
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Affiliation(s)
- Jürgen Kreiter
- Institute of Physiology, Pathophysiology and Biophysics, Department of Biomedical Sciences, University of Veterinary Medicine, 1210 Vienna, Austria; (J.K.); (A.R.); (K.Ž.); (S.B.)
| | - Anne Rupprecht
- Institute of Physiology, Pathophysiology and Biophysics, Department of Biomedical Sciences, University of Veterinary Medicine, 1210 Vienna, Austria; (J.K.); (A.R.); (K.Ž.); (S.B.)
- Institute of Pharmacology and Toxicology, Rostock University Medical Center, 18057 Rostock, Germany
| | - Sanja Škulj
- Division of Organic Chemistry and Biochemistry, Rudjer Bošković Institute,10000 Zagreb, Croatia; (S.Š.); (Z.B.); (M.V.)
| | - Zlatko Brkljača
- Division of Organic Chemistry and Biochemistry, Rudjer Bošković Institute,10000 Zagreb, Croatia; (S.Š.); (Z.B.); (M.V.)
| | - Kristina Žuna
- Institute of Physiology, Pathophysiology and Biophysics, Department of Biomedical Sciences, University of Veterinary Medicine, 1210 Vienna, Austria; (J.K.); (A.R.); (K.Ž.); (S.B.)
| | - Denis G. Knyazev
- Institute of Biophysics, Johannes Kepler University, 4020 Linz, Austria;
| | - Sarah Bardakji
- Institute of Physiology, Pathophysiology and Biophysics, Department of Biomedical Sciences, University of Veterinary Medicine, 1210 Vienna, Austria; (J.K.); (A.R.); (K.Ž.); (S.B.)
| | - Mario Vazdar
- Division of Organic Chemistry and Biochemistry, Rudjer Bošković Institute,10000 Zagreb, Croatia; (S.Š.); (Z.B.); (M.V.)
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, 16610 Prague 6, Czech Republic
| | - Elena E. Pohl
- Institute of Physiology, Pathophysiology and Biophysics, Department of Biomedical Sciences, University of Veterinary Medicine, 1210 Vienna, Austria; (J.K.); (A.R.); (K.Ž.); (S.B.)
- Correspondence:
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Gontsarik M, Yaghmur A, Salentinig S. Dispersed liquid crystals as pH-adjustable antimicrobial peptide nanocarriers. J Colloid Interface Sci 2021; 583:672-682. [DOI: 10.1016/j.jcis.2020.09.081] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 09/15/2020] [Accepted: 09/19/2020] [Indexed: 02/06/2023]
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29
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Ansari MJ, Alnakhli M, Al-Otaibi T, Meanazel OA, Anwer MK, Ahmed MM, Alshahrani SM, Alshetaili A, Aldawsari MF, Alalaiwe AS, Alanazi AZ, Zahrani MA, Ahmad N. Formulation and evaluation of self-nanoemulsifying drug delivery system of brigatinib: Improvement of solubility, in vitro release, ex-vivo permeation and anticancer activity. J Drug Deliv Sci Technol 2021. [DOI: 10.1016/j.jddst.2020.102204] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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30
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Clathrin senses membrane curvature. Biophys J 2021; 120:818-828. [PMID: 33524373 DOI: 10.1016/j.bpj.2020.12.035] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Revised: 11/23/2020] [Accepted: 12/07/2020] [Indexed: 11/21/2022] Open
Abstract
The ability of proteins to assemble at sites of high membrane curvature is essential to diverse membrane remodeling processes, including clathrin-mediated endocytosis. Multiple adaptor proteins within the clathrin pathway have been shown to sense regions of high membrane curvature, leading to local recruitment of the clathrin coat. Because clathrin triskelia do not bind to the membrane directly, it has remained unclear whether the clathrin coat plays an active role in sensing membrane curvature or is passively recruited by adaptor proteins. Using a synthetic tag to assemble clathrin directly on membrane surfaces, here we show that clathrin is a strong sensor of membrane curvature, comparable with previously studied adaptor proteins. Interestingly, this sensitivity arises from clathrin assembly rather than from the properties of unassembled triskelia, suggesting that triskelia have preferred angles of interaction, as predicted by earlier structural data. Furthermore, when clathrin is recruited by adaptors, its curvature sensitivity is amplified by 2- to 10-fold, such that the resulting protein complex is up to 100 times more likely to assemble on a highly curved surface compared with a flatter one. This exquisite sensitivity points to a synergistic relationship between the coat and its adaptor proteins, which enables clathrin to pinpoint sites of high membrane curvature, an essential step in ensuring robust membrane traffic. More broadly, these findings suggest that protein networks, rather than individual protein domains, are likely the most potent drivers of membrane curvature sensing.
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Yeo S, Jung S, Cho HK, Kim YH, Kim GH, Kim D, Ko BH, Lee J. Design and Characterization of Elastic Artificial Skin Containing Adenosine-Loaded Solid Lipid Nanoparticles for Treating Wrinkles. Pharmaceutics 2020; 13:33. [PMID: 33379295 PMCID: PMC7823613 DOI: 10.3390/pharmaceutics13010033] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 12/22/2020] [Accepted: 12/25/2020] [Indexed: 11/16/2022] Open
Abstract
Adenosine (AD), which is used for treating wrinkles, exhibits poor skin permeation. The aim of the present study was to develop a cross-linked silicone-based cellulose elastomer as an elastic artificial skin for the treatment of skin wrinkles, a biocompatible lipid-based nano-carrier for enhancing the skin permeation of AD, and a formulation consisting of the lipid-based carrier incorporated in the elastic artificial skin. AD-loaded solid lipid nanoparticles (SLNs) were prepared using a double-emulsion method. Particle characteristics and mechanical properties of SLNs and elastic artificial skin, respectively, were assessed. Skin permeation was evaluated using SkinEthic RHE tissue, a reconstructed human epidermis model. The mean particle size and zeta potential for SLNs ranged from 123.57 to 248.90 nm and -13.23 to -41.23 mV, respectively. The components of neither SLNs nor the elastic artificial skin were cytotoxic, according to cell- and tissue-viability assays and EU classification. SLNs and the elastic artificial skin exhibited sustained drug release for 48 h. The amount of AD released from SLNs and elastic artificial skin was approximately 10 times and 5 times higher, respectively, than that from AD solution. Therefore, elastic artificial skin incorporated with AD-loaded SLNs may serve as a promising topical delivery system for cosmeceutical treatment of skin wrinkles.
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Affiliation(s)
- Sooho Yeo
- College of Pharmacy, Chung-Ang University, Seoul 06974, Korea; (S.Y.); (S.J.); (D.K.); (B.H.K.)
| | - Sukkyun Jung
- College of Pharmacy, Chung-Ang University, Seoul 06974, Korea; (S.Y.); (S.J.); (D.K.); (B.H.K.)
| | - Heui Kyoung Cho
- R&D Center, Megacos, 16, Simin-daero 327 Rd, Dongan-gu, Anyang-si, Gyeonggi-do 14055, Korea; (H.K.C.); (Y.H.K.); (G.H.K.)
| | - Young Ho Kim
- R&D Center, Megacos, 16, Simin-daero 327 Rd, Dongan-gu, Anyang-si, Gyeonggi-do 14055, Korea; (H.K.C.); (Y.H.K.); (G.H.K.)
| | - Gi Hwan Kim
- R&D Center, Megacos, 16, Simin-daero 327 Rd, Dongan-gu, Anyang-si, Gyeonggi-do 14055, Korea; (H.K.C.); (Y.H.K.); (G.H.K.)
| | - Dohyun Kim
- College of Pharmacy, Chung-Ang University, Seoul 06974, Korea; (S.Y.); (S.J.); (D.K.); (B.H.K.)
| | - Byoung Hyen Ko
- College of Pharmacy, Chung-Ang University, Seoul 06974, Korea; (S.Y.); (S.J.); (D.K.); (B.H.K.)
| | - Jaehwi Lee
- College of Pharmacy, Chung-Ang University, Seoul 06974, Korea; (S.Y.); (S.J.); (D.K.); (B.H.K.)
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Kumar JBS, Sharma B. A review on neuropharmacological role of erucic acid: an omega-9 fatty acid from edible oils. Nutr Neurosci 2020; 25:1041-1055. [PMID: 33054628 DOI: 10.1080/1028415x.2020.1831262] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Neurodegenerative diseases (ND) are characterised by loss of neurons in the brain and spinal cord. For the normal functioning of the brain, divers group of fatty acids in the form of glycerophospholipids, glycerol ether lipids, cerebrosides, sulfatides, and gangliosides are essential. They are present abundantly in the nervous system and are actively involved in both the development and maintenance of the nervous system. A dietary deficiency of essential fatty acid during development results in hypomyelination state which affects various neuronal functions. Several studies suggested that age remains the primary risk factor for almost all neurodegenerative disorders. The potential contribution of these fatty acids in the progression of neurodegenerative disorders is indispensable. Erucic acid an omega 9 fatty acid, which is obtained from edible oils has proven to cause myocardial lipidosis, heart lesions and hepatic steatosis in animals therefore, its content in edible oils is restricted to certain levels by regulatory agencies. However, erucic acid in the form of a mixture with oleic acid is often used as a dietary treatment for the management of adrenoleukodystrophy without any cardiotoxicity. Our literature search revealed that, erucic acid reported to enhance cognitive function, interact with peroxisome proliferator activated receptors (PPARs), inhibit elastase and thrombin. In this review first we have attempted to describe the relationship between fatty acids and neurodegeneration followed by a description on the pharmacology of erucic acid. The overall purpose of this review is to analyse toxic and beneficial neuropharmacological effects of erucic acid.
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Affiliation(s)
- J B Senthil Kumar
- Special centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India.,School of Medical and Allied Sciences, KR Mangalam University, Delhi NCR, India
| | - Bhawna Sharma
- School of Medical and Allied Sciences, KR Mangalam University, Delhi NCR, India
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33
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Chang YC, Liu HQ, Chang JH, Chang YY, Lin EC. Role of the cholesterol hydroxyl group in the chemical exchange saturation transfer signal at -1.6 ppm. NMR IN BIOMEDICINE 2020; 33:e4356. [PMID: 32575161 DOI: 10.1002/nbm.4356] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Revised: 05/10/2020] [Accepted: 05/29/2020] [Indexed: 06/11/2023]
Abstract
Chemical exchange saturation transfer (CEST) can provide metabolite-weighted images in the clinical setting; therefore, understanding the origin of each CEST signal is essential to revealing the changes in diseases at the molecular level, which would provide further insight for diagnoses and treatments. The CEST signal at -1.6 ppm is attributed to the choline methyl group of phosphatidylcholines. The methyl groups have no exchangeable protons, so the corresponding CEST signals must result from the relayed nuclear Overhauser effect (rNOE); however, the detailed mechanism remains unclear. Cholesterol is a major component of biological membranes, and its content is closely related to the dynamics and phases of these lipids. However, cholesterol has a hydroxyl group, which could participate in proton exchange to complete the rNOE process. In this study, we used liposomes containing cholesterol and its analogs (5α-cholestane and progesterone), which presumably have similar capabilities of influencing lipid bilayers, and found that the steroid hydroxyl group is the key to inducing the rNOE at -1.6 ppm. Our results suggest that the origin of the rNOE at -1.6 ppm likely requires an intermolecular NOE between the proton of the choline methyl group and that of the cholesterol hydroxyl group, and a chemical exchange between the cholesterol hydroxyl group and bulk water. However, the phenomenon in which the rNOE at -1.6 ppm appears when the cholesterol concentration is high seems to contradict the in vivo results, suggesting a more complicated mechanism associated with the rNOE at -1.6 ppm in biological membranes.
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Affiliation(s)
- Yu-Chi Chang
- Department of Chemistry and Biochemistry, National Chung Cheng University, Chiayi, Taiwan
| | - Hong-Qing Liu
- Department of Chemistry and Biochemistry, National Chung Cheng University, Chiayi, Taiwan
| | - Jung-Hsuan Chang
- Department of Chemistry and Biochemistry, National Chung Cheng University, Chiayi, Taiwan
| | - Yu-Yen Chang
- Department of Chemistry and Biochemistry, National Chung Cheng University, Chiayi, Taiwan
| | - Eugene C Lin
- Department of Chemistry and Biochemistry, National Chung Cheng University, Chiayi, Taiwan
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Chantadee T, Santimaleeworagun W, Phorom Y, Phaechamud T. Saturated Fatty Acid-Based In Situ Forming Matrices for Localized Antimicrobial Delivery. Pharmaceutics 2020; 12:pharmaceutics12090808. [PMID: 32854439 PMCID: PMC7559323 DOI: 10.3390/pharmaceutics12090808] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 08/13/2020] [Accepted: 08/21/2020] [Indexed: 02/06/2023] Open
Abstract
In recent years, the world has faced the issue of antibiotic resistance. Methicillin-resistant Staphylococcus aureus (MRSA) is a significant problem in various treatments and control of infections. Biocompatible materials with saturated fatty acids of different chain lengths (C8-C18) were studied as matrix formers of localized injectable vancomycin HCl (VCM)-loaded antisolvent-induced in situ forming matrices. The series of fatty acid-based in situ forming matrices showed a low viscosity (5.47-13.97 cPs) and pH value in the range of 5.16-6.78, with high injectability through a 27-G needle (1.55-3.12 N). The preparations exhibited low tolerance to high concentrations of KH2PO4 solution (1.88-5.42% v/v) and depicted an electrical potential change during phase transformation. Their phase transition and matrix formation at the microscopic and macroscopic levels depended on the chain length of fatty acids and solvent characteristics. The VCM release pattern depended on the nucleation/crystallization and solvent exchange behaviors of the delivery system. The 35% w/v of C12-C16 fatty acid-based in situ forming matrix prolonged the VCM release over seven days in which C12, C14, C16 -based formulation reached 56, 84, and 85% cumulative drug release at 7th day. The release data fitted well with Higuchi's model. The developed formulations presented efficient antimicrobial activities against standard S. aureus, MRSA, Escherichia coli, and Candida albicans. Hence, VCM-loaded antisolvent-induced fatty acid-based in situ forming matrix is a potential local delivery system for the treatment of local Gram-positive infection sites, such as joints, eyes, dermis of surgery sites, etc., in the future.
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Affiliation(s)
- Takron Chantadee
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Silpakorn University, Nakhon Pathom 73000, Thailand
- Correspondence: (T.C.); (T.P.); Tel.: +66-034-255800 (T.C. & T.P.)
| | - Wichai Santimaleeworagun
- Department of Pharmacy, Faculty of Pharmacy, Silpakorn University, Nakhon Pathom 73000, Thailand;
| | - Yaowaruk Phorom
- Secretary Office of Faculty, Faculty of Pharmacy, Silpakorn University, Nakhon Pathom 73000, Thailand;
| | - Thawatchai Phaechamud
- Department of Pharmaceutical Technology, Faculty of Pharmacy, Silpakorn University, Nakhon Pathom 73000, Thailand
- Natural Bioactive and Material for Health Promotion and Drug Delivery System Group (NBM Group), Faculty of Pharmacy, Silpakorn University, Nakhon Pathom 73000, Thailand
- Correspondence: (T.C.); (T.P.); Tel.: +66-034-255800 (T.C. & T.P.)
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Grünewald F, Souza PCT, Abdizadeh H, Barnoud J, de Vries AH, Marrink SJ. Titratable Martini model for constant pH simulations. J Chem Phys 2020; 153:024118. [PMID: 32668918 DOI: 10.1063/5.0014258] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
In this work, we deliver a proof of concept for a fast method that introduces pH effects into classical coarse-grained (CG) molecular dynamics simulations. Our approach is based upon the latest version of the popular Martini CG model to which explicit proton mimicking particles are added. We verify our approach against experimental data involving several different molecules and different environmental conditions. In particular, we compute titration curves, pH dependent free energies of transfer, and lipid bilayer membrane affinities as a function of pH. Using oleic acid as an example compound, we further illustrate that our method can be used to study passive translocation in lipid bilayers via protonation. Finally, our model reproduces qualitatively the expansion of the macromolecule dendrimer poly(propylene imine) as well as the associated pKa shift of its different generations. This example demonstrates that our model is able to pick up collective interactions between titratable sites in large molecules comprising many titratable functional groups.
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Affiliation(s)
- Fabian Grünewald
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials, University of Groningen, Groningen, The Netherlands
| | - Paulo C T Souza
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials, University of Groningen, Groningen, The Netherlands
| | - Haleh Abdizadeh
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials, University of Groningen, Groningen, The Netherlands
| | - Jonathan Barnoud
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials, University of Groningen, Groningen, The Netherlands
| | - Alex H de Vries
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials, University of Groningen, Groningen, The Netherlands
| | - Siewert J Marrink
- Groningen Biomolecular Sciences and Biotechnology Institute and Zernike Institute for Advanced Materials, University of Groningen, Groningen, The Netherlands
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Zhang P, Pham T, Zheng X, Liu C, Plata PL, Král P, Bu W, Lin B, Liu Y. Spontaneous collapse of palmitic acid films on an alkaline buffer containing calcium ions. Colloids Surf B Biointerfaces 2020; 193:111100. [PMID: 32408262 DOI: 10.1016/j.colsurfb.2020.111100] [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: 01/26/2020] [Revised: 04/27/2020] [Accepted: 04/28/2020] [Indexed: 10/24/2022]
Abstract
Understanding the interaction of ions with fatty acids is important to identify their roles in various bioprocesses and to build novel biomimetic systems. In this study, the molecular organization of palmitic acid (PA) films on alkaline buffer solutions (pH 7.4) with and without divalent Ca2+ was measured at a constant surface area using Langmuir troughs coupled with microscopy and X-ray interfacial techniques. Without Ca2+, PA molecules remained a monolayer organization; however, with Ca2+, formation of the inverted bilayers of PA-Ca2+ superstructures caused a spontaneous 2D to 3D transformation under no compression due to the strong interaction between PA and the divalent cation. Self-assembly of this highly-organized inverted bilayer superstructure involved a two-step process of nucleation and nuclei growth. During nucleation, densely packed PA and Ca2+ monolayer firstly corrugated and some of PA and Ca2+ molecules ejected out from the monolayer; the ejected molecules then reorganized and formed the inverted bilayer nuclei. Nucleation was followed by nuclei growth, during which PA and Ca2+ in the monolayer kept integrating into the inverted bilayer structure through molecule migration and PA rotation around Ca2+.
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Affiliation(s)
- Pin Zhang
- Department of Chemical Engineering, University of Illinois at Chicago, Chicago, IL 60608, United States
| | - Tiep Pham
- Department of Chemical Engineering, University of Illinois at Chicago, Chicago, IL 60608, United States
| | - Xin Zheng
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL 60607, United States
| | - Chang Liu
- Department of Chemical Engineering, University of Illinois at Chicago, Chicago, IL 60608, United States
| | - Paola Leon Plata
- Department of Chemical Engineering, University of Illinois at Chicago, Chicago, IL 60608, United States
| | - Petr Král
- Department of Chemical Engineering, University of Illinois at Chicago, Chicago, IL 60608, United States; Department of Chemistry, University of Illinois at Chicago, Chicago, IL 60607, United States; Department of Physics, University of Illinois at Chicago, Chicago, IL 60607, United States; Department of Biopharmaceutical Sciences, University of Illinois at Chicago, Chicago, IL 60607, United States
| | - Wei Bu
- NSF's ChemMatCARS, University of Chicago, IL 60637, United States
| | - Binhua Lin
- NSF's ChemMatCARS, University of Chicago, IL 60637, United States
| | - Ying Liu
- Department of Chemical Engineering, University of Illinois at Chicago, Chicago, IL 60608, United States; Department of Biopharmaceutical Sciences, University of Illinois at Chicago, Chicago, IL 60607, United States; Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, United States.
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Dharmaraj K, Román Silva JI, Kahlert H, Lendeckel U, Scholz F. The acid-base and redox properties of menaquinone MK-4, MK-7, and MK-9 (vitamin K 2) in DMPC monolayers on mercury. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2020; 49:279-288. [PMID: 32372117 PMCID: PMC7244470 DOI: 10.1007/s00249-020-01433-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 03/16/2020] [Accepted: 04/20/2020] [Indexed: 01/07/2023]
Abstract
Abstract The acid–base and redox properties of the menaquinones MK-4, MK-7, and MK-9 (vitamin K2) have been studied in DMPC monolayers on mercury electrodes. The monolayers were prepared by adhesion-spreading of menaquinone-spiked DMPC liposomes on a stationary mercury drop electrode. All three menaquinones possess \documentclass[12pt]{minimal}
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\begin{document}$${\text{p}}K_{{\text{a}}}$$\end{document}pKa constants outside the experimentally accessible range, i.e., they are higher than about 12. The standard potentials of MK-4, MK-7, and MK-9 in the DMPC monolayers are very similar, i.e., 0.351, 0.326, and 0.330 V (corresponding to the biochemical standard potentials − 0.063, − 0.088, and − 0.085 V). Graphic abstract ![]()
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Affiliation(s)
- Karuppasamy Dharmaraj
- Institute of Biochemistry, University of Greifswald, Felix-Hausdorff-Str. 4, 17487, Greifswald, Germany
| | | | - Heike Kahlert
- Institute of Biochemistry, University of Greifswald, Felix-Hausdorff-Str. 4, 17487, Greifswald, Germany
| | - Uwe Lendeckel
- Institute of Medical Biochemistry and Molecular Biology, University Medicine Greifswald, University of Greifswald, Ferdinand-Sauerbruch-Str., 17475, Greifswald, Germany
| | - Fritz Scholz
- Institute of Biochemistry, University of Greifswald, Felix-Hausdorff-Str. 4, 17487, Greifswald, Germany.
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Silva CM, Ferrari GD, Alberici LC, Malaspina O, Moraes KCM. Cellular and molecular effects of silymarin on the transdifferentiation processes of LX-2 cells and its connection with lipid metabolism. Mol Cell Biochem 2020; 468:129-142. [PMID: 32185674 DOI: 10.1007/s11010-020-03717-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Accepted: 03/06/2020] [Indexed: 12/17/2022]
Abstract
Fibrosis process in the liver is a clinical condition established in response to chronic lesions and may be reversible in many situations. In this process, hepatic stellate cells (HSCs) activate and produce extracellular matrix compounds. During fibrosis, the lipid metabolism is also altered and contributes to the transdifferentiation of the HSCs. Thus, controlling lipid metabolism in HSCs is suggested as a method to control or reverse the fibrotic condition. In the search for therapies that modulate lipid metabolism and treat liver diseases, silymarin has been identified as a relevant natural compound to treat liver pathologies. The present study aimed to evaluate the cellular and molecular effects of silymarin in the transdifferentiation process of HSCs (LX-2) from activated phenotype to a more quiesced-like cells , also focusing on understanding the modulatory effects of silymarin on lipid metabolism of HSCs. In our analyses, 100 µM of silymarin reduced the synthesis of actin filaments in activated cells, the synthesis of the protein level of α-SMA, and other pro-fibrotic factors such as CTGF and PFGF. The concentration of 150 µM silymarin did not reverse the activation aspects of LX-2 cells. However, both evaluated concentrations of the natural compound protected the cells from the negative effects of dimethyl sulfoxide (DMSO). Furthermore, we evaluated lipid-related molecules correlated to the transdifferentiation process of LX-2, and 100 µM of silymarin demonstrated to control molecules associated with lipid metabolism such as FASN, MLYCD, ACSL4, CPTs, among others. In contrast, cellular incubation with 150 µM of silymarin increased the synthesis of long-chain fatty acids and triglycerides, regarding the higher presence of DMSO (v/v) in the solvent. In conclusion, silymarin acts as a hepatoprotective agent and modulates the pro-fibrogenic stimuli of LX-2 cells, whose effects depend on stress levels in the cellular environment.
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Affiliation(s)
- Caio Mateus Silva
- Laboratório de Biologia Molecular, Departamento de Biologia Geral e Aplicada, Instituto de Biociências, Universidade Estadual Paulista, UNESP, Rio Claro, SP, 13506-900, Brazil
| | - Gustavo Duarte Ferrari
- Departamento de Bioquímica E Imunologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, USP, Ribeirão Preto, SP, Brazil
| | - Luciane Carla Alberici
- Departamento de Física E Química, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, USP, Ribeirão Preto, SP, Brazil
| | - Osmar Malaspina
- Centro de Estudos de Insetos Sociais, Instituto de Biociências, Universidade Estadual Paulista, UNESP, Rio Claro, SP, Brazil
| | - Karen C M Moraes
- Laboratório de Biologia Molecular, Departamento de Biologia Geral e Aplicada, Instituto de Biociências, Universidade Estadual Paulista, UNESP, Rio Claro, SP, 13506-900, Brazil.
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Algal Lipids as Biocollector for Recovery of Coal from Fine Coal Waste by Froth Flotation. MINERALS 2020. [DOI: 10.3390/min10010070] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Raw algal lipids (RALs) and their derivatives (fatty acid methyl esters; FAMEs) were investigated as biocollectors for the recovery of coal from ash-rich fine coal waste by froth flotation. Testing was done on fine coal discards from two South African sites—a high ash (50%), high sulphur (5.7%) sample and a lower ash (26%), low sulphur (0.91%) sample. The yield and recovery of combustibles on using biocollectors was similar to, or better than, with oleic acid, a polar collector demonstrated as a good collector in previous research. The RALs and FAMEs reduced the ash and sulphur content of the combustible fraction of the high ash-high sulphur sample to between 23–28% and 1.9–3.3%, respectively. The chemical modification of RALs to FAMEs provided potential for improving the selectivity of the recovery of combustibles. It also resulted in a change of the optimum operating pH, with RALs yielding better results at the natural pH of the sample (pH 2.7), while FAMEs performed best at pH 7.
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Tan Y, Li R, Zhou H, Liu J, Muriel Mundo J, Zhang R, McClements DJ. Impact of calcium levels on lipid digestion and nutraceutical bioaccessibility in nanoemulsion delivery systems studied using standardized INFOGEST digestion protocol. Food Funct 2020; 11:174-186. [DOI: 10.1039/c9fo01669d] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The bioaccessibility of hydrophobic bioactives may be greatly reduced in the presence of calcium.
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Affiliation(s)
- Yunbing Tan
- Department of Food Science
- University of Massachusetts Amherst
- Amherst
- USA
| | - Ruyi Li
- State Key Laboratory of Food Science and Technology
- Nanchang University
- 8 Nanchang
- PR China
| | - Hualu Zhou
- Department of Food Science
- University of Massachusetts Amherst
- Amherst
- USA
| | - Jinning Liu
- Department of Food Science
- University of Massachusetts Amherst
- Amherst
- USA
| | | | - Ruojie Zhang
- Department of Food Science
- University of Massachusetts Amherst
- Amherst
- USA
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41
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Farkuh L, Hennies PT, Nunes C, Reis S, Barreiros L, Segundo MA, Oseliero Filho PL, Oliveira CLP, Cassago A, Portugal RV, Muramoto RA, Carretero GPB, Schreier S, Chaimovich H, Cuccovia IM. Characterization of phospholipid vesicles containing lauric acid: physicochemical basis for process and product development. Heliyon 2019; 5:e02648. [PMID: 31720452 PMCID: PMC6838897 DOI: 10.1016/j.heliyon.2019.e02648] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 09/12/2019] [Accepted: 10/09/2019] [Indexed: 11/24/2022] Open
Abstract
Lauric acid (LAH) strongly inhibits the growth of acne-causing bacteria. LAH is essentially water-insoluble and the solubility of laurate (LA) salts are medium and temperature dependent. Hence, LAH/LA preparations are difficult to formulate. Here we fully characterized phospholipid vesicles containing up to 50 mol% LAH. Vesicles of dipalmitoylphosphatidylcholine (DPPC) containing LAH, at pHs 7.4 and 5.0, were characterized measuring size, charge, bilayer phase transition temperature (Tm) and permeability of water-soluble probes. Small angle X-ray scattering and cryotransmission electron microscopy showed multilamellar vesicles at low LAH %. Increasing LAH % had a negligible effect on particle size. An internal aqueous compartment in all vesicle's preparations, even at equimolar DPPC: LAH fractions, was demonstrated using water-soluble probes. At pH 5.0, the interaction between DPPC and LAH increased the Tm and phase transition cooperativity showing a single lipid phase formed by hydrogen-bonded DPPC: LAH complexes. At pH 7.4, vesicles containing 50 mol% LAH exhibited distinct phases, ascribed to complex formation between LAH and LA or LAH and DPPC. LAH incorporated in the vesicles minimally permeated a skin preparation at both pHs, indicating that the primary sites of LAH solubilization were the skin layers. These results provide the foundations for developing processes and products containing DPPC: LAH.
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Affiliation(s)
- Laura Farkuh
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | | | - Cláudia Nunes
- LAQV, REQUIMTE, Faculty of Pharmacy, University of Porto, Porto, Portugal
| | - Salette Reis
- LAQV, REQUIMTE, Faculty of Pharmacy, University of Porto, Porto, Portugal
| | - Luisa Barreiros
- LAQV, REQUIMTE, Faculty of Pharmacy, University of Porto, Porto, Portugal
| | - Marcela A Segundo
- LAQV, REQUIMTE, Faculty of Pharmacy, University of Porto, Porto, Portugal
| | - Pedro L Oseliero Filho
- Department of Experimental Physics, Institute of Physics, University of São Paulo, São Paulo, Brazil
| | - Cristiano L P Oliveira
- Department of Experimental Physics, Institute of Physics, University of São Paulo, São Paulo, Brazil
| | - Alexandre Cassago
- Brazilian Nanotechnology National Laboratory (LNNano), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, Brazil
| | - Rodrigo V Portugal
- Brazilian Nanotechnology National Laboratory (LNNano), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, Brazil
| | - Rodrigo A Muramoto
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | - Gustavo P B Carretero
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | - Shirley Schreier
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | - Hernan Chaimovich
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
| | - Iolanda M Cuccovia
- Department of Biochemistry, Institute of Chemistry, University of São Paulo, São Paulo, Brazil
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Škulj S, Vazdar M. Calculation of apparent pK a values of saturated fatty acids with different lengths in DOPC phospholipid bilayers. Phys Chem Chem Phys 2019; 21:10052-10060. [PMID: 31046041 DOI: 10.1039/c9cp01204d] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We performed all-atom molecular dynamics simulations and calculated free energy profiles and apparent pKa values for neutral and anionic forms of single myristic (C14:0), palmitic (C16:0) and stearic (C18:0) fatty acid embedded in a DOPC bilayer and explicit water solvent. We showed that the neutral forms of the fatty acids are stabilized inside the bilayer by hydrogen bonding of a fatty acid carboxylic group with DOPC phosphate and carbonyl groups. In contrast to the neutral form, the anionic forms of the fatty acids are shifted towards the water-membrane interface and are instead stabilized by hydrogen bonding to interfacial water. By using umbrella sampling simulations, we calculated free energies of stabilization and revealed that the free energy of stabilization inside the bilayer increases with the chain length for both the neutral and deprotonated forms. On the other hand, the free energies of flip-flop of both the neutral and anionic forms are constant upon the prolongation of the fatty acid. Based on the free energy curves, we also calculated apparent fatty acid pKa,app values in the bilayer, which are 7.0, 7.2 and 6.3 for myristic, palmitic and stearic acid and are increased by several pKa units compared to the corresponding pKa values in water. By further analysis of the calculated curves we found that spontaneous protonation of fatty acid anions takes place in the bilayer interior at ca. 1.4 nm from the bilayer center for all studied fatty acids.
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Affiliation(s)
- Sanja Škulj
- Division of Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička 54, HR-10000 Zagreb, Croatia.
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43
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Pohl EE, Rupprecht A, Macher G, Hilse KE. Important Trends in UCP3 Investigation. Front Physiol 2019; 10:470. [PMID: 31133866 PMCID: PMC6524716 DOI: 10.3389/fphys.2019.00470] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Accepted: 04/04/2019] [Indexed: 11/13/2022] Open
Abstract
Membrane uncoupling protein 3 (UCP3), a member of the mitochondrial uncoupling protein family, was discovered in 1997. UCP3's properties, such as its high homology to other mitochondrial carriers, especially to UCP2, its short lifetime and low specificity of UCP3 antibodies, have hindered progress in understanding its biological function and transport mechanism over decades. The abundance of UCP3 is highest in murine brown adipose tissue (BAT, 15.0 pmol/mg protein), compared to heart (2.7 pmol/mg protein) and the gastrocnemius muscle (1.7 pmol/mg protein), but it is still 400-fold lower than the abundance of UCP1, a biomarker for BAT. Investigation of UCP3 reconstituted in planar bilayer membranes revealed that it transports protons only when activated by fatty acids (FA). Although purine nucleotides (PN) inhibit UCP3-mediated transport, the molecular mechanism differs from that of UCP1. It remains a conundrum that two homologous proton-transporting proteins exist within the same tissue. Recently, we proposed that UCP3 abundance directly correlates with the degree of FA β-oxidation in cell metabolism. Further development in this field implies that UCP3 may have dual function in transporting substrates, which have yet to be identified, alongside protons. Evaluation of the literature with respect to UCP3 is a complex task because (i) UCP3 features are often extrapolated from its "twin" UCP2 without additional proof, and (ii) the specificity of antibodies against UCP3 used in studies is rarely evaluated. In this review, we primarily focus on recent findings obtained for UCP3 in biological and biomimetic systems.
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Affiliation(s)
- Elena E. Pohl
- Institute of Physiology, Pathophysiology and Biophysics, University of Veterinary Medicine, Vienna, Austria
| | - Anne Rupprecht
- Institute of Physiology, Pathophysiology and Biophysics, University of Veterinary Medicine, Vienna, Austria
- Institute of Pharmacology and Toxicology, Rostock University Medical Center, Rostock, Germany
| | - Gabriel Macher
- Institute of Physiology, Pathophysiology and Biophysics, University of Veterinary Medicine, Vienna, Austria
| | - Karolina E. Hilse
- Institute of Physiology, Pathophysiology and Biophysics, University of Veterinary Medicine, Vienna, Austria
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Abstract
Spontaneous solute and solvent permeation through membranes is of vital importance to human life, be it gas exchange in red blood cells, metabolite excretion, drug/toxin uptake, or water homeostasis. Knowledge of the underlying molecular mechanisms is the sine qua non of every functional assignment to membrane transporters. The basis of our current solubility diffusion model was laid by Meyer and Overton. It correlates the solubility of a substance in an organic phase with its membrane permeability. Since then, a wide range of studies challenging this rule have appeared. Commonly, the discrepancies have their origin in ill-used measurement approaches, as we demonstrate on the example of membrane CO2 transport. On the basis of the insight that scanning electrochemical microscopy offered into solute concentration distributions in immediate membrane vicinity of planar membranes, we analyzed the interplay between chemical reactions and diffusion for solvent transport, weak acid permeation, and enzymatic reactions adjacent to membranes. We conclude that buffer reactions must also be considered in spectroscopic investigations of weak acid transport in vesicular suspensions. The evaluation of energetic contributions to membrane translocation of charged species demonstrates the compatibility of the resulting membrane current with the solubility diffusion model. A local partition coefficient that depends on membrane penetration depth governs spontaneous membrane translocation of both charged and uncharged molecules. It is determined not only by the solubility in an organic phase but also by other factors like cholesterol concentration and intrinsic electric membrane potentials.
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Affiliation(s)
- Christof Hannesschlaeger
- From the Institute of Biophysics , Johannes Kepler University Linz , Gruberstrasse 40 , 4020 Linz , Austria
| | - Andreas Horner
- From the Institute of Biophysics , Johannes Kepler University Linz , Gruberstrasse 40 , 4020 Linz , Austria
| | - Peter Pohl
- From the Institute of Biophysics , Johannes Kepler University Linz , Gruberstrasse 40 , 4020 Linz , Austria
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45
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Ježek P, Jabůrek M, Porter RK. Uncoupling mechanism and redox regulation of mitochondrial uncoupling protein 1 (UCP1). BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2019; 1860:259-269. [DOI: 10.1016/j.bbabio.2018.11.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 10/15/2018] [Accepted: 11/07/2018] [Indexed: 01/11/2023]
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46
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Rokitskaya TI, Korshunova GA, Antonenko YN. Effect of Alkyl Chain Length on Translocation of Rhodamine B n-Alkyl Esters across Lipid Membranes. Biophys J 2018; 115:514-521. [PMID: 30031539 DOI: 10.1016/j.bpj.2018.07.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 06/27/2018] [Accepted: 07/02/2018] [Indexed: 01/03/2023] Open
Abstract
Voltage-dependent translocation of a series of cationic rhodamine B derivatives differing in n-alkyl chain length (ethyl, butyl, octyl, dodecyl, octadecyl) from one lipid monolayer to another was studied by measuring electrical current relaxation after a voltage jump on a planar bilayer phosphatidylcholine (PC) membrane. The rate of the translocation decreased in the following series of lipids: diphytanyl-PC > dioleyl-PC > diphytanoyl-PC > dierucoyl-PC. For all the lipids studied, the rate increased with lengthening of the hydrocarbon chain of the rhodamine derivatives, with the increase being most pronounced for the compounds having a short alkyl chain. The results could be well explained by involvement of molecule reorientations in the process of transmembrane flip-flop of the hydrophobic membrane-bound compounds. However, an impact of membrane dipole potential on the translocation rate could not be excluded, because the dipole potential could contribute to the energy barrier for translocation of the compounds located at different depths in the water-membrane interface. Based on the data obtained, a difference in the dipole potential of ester diphytanoyl-PC membranes with respect to ether diphytanyl-PC was estimated to be 108 mV, highlighting the contribution of a layer of oriented carbonyl groups of the lipids to the membrane dipole potential.
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Affiliation(s)
- Tatyana I Rokitskaya
- 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
| | - Yuri N Antonenko
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, Russia
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