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Raghavendra, Kumar B, Chari SN. Effect of γ-Oryzanol on the LE-LC Phase Coexistence Region of DPPC Langmuir Monolayer. J Membr Biol 2023; 256:413-422. [PMID: 37269365 DOI: 10.1007/s00232-023-00288-8] [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: 03/22/2023] [Accepted: 05/06/2023] [Indexed: 06/05/2023]
Abstract
We have studied the effect of relative composition of γ-Oryzanol (γ-Or) on the liquid expanded-liquid condensed phase coexistence region in the mixed Langmuir monolayer of γ-Or and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) molecules at air-water interface. The surface manometry studies at a fixed temperature show that the mixture of γ-Or and DPPC forms a stable monolayer at air-water interface. As the relative composition of γ-Or increases the range of area per molecule over which the coexistence of liquid expanded (LE)-liquid condensed (LC) phases exists reduces. Although the LE-LC phase coexistence corresponds to the first-order phase transition, the slope of the surface pressure-area per molecule isotherm is non-zero. Earlier studies have attributed the non-zero slope in LE-LC phase coexistence region to the influence of the strain between the ordered LC phase and disordered LE phase. The effect of strain on the coexistence of LE-LC phases can be studied in terms of molecular density-strain coupling. Our analysis of the liquid condensed-liquid expanded coexistence region in the isotherms of mixed monolayers of DPPC and γ-Or shows that with the increase in the mole fraction of sterol in the mixed monolayer the molecular lateral density-strain coupling increases. However, at 0.6 mole fraction of γ-Or in the mixed monolayer the coupling decreases. This is corroborated by the observation of minimum Gibb's free energy of the mixed monolayer at this relative composition of γ-Or indicating better packing of molecules.
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Affiliation(s)
- Raghavendra
- Department of Physics, Central University of Karnataka, Aland Road, Kadaganchi, Kalaburagi, Karnataka, 585102, India
| | - Bharat Kumar
- Department of Physics, Central University of Karnataka, Aland Road, Kadaganchi, Kalaburagi, Karnataka, 585102, India.
| | - Siva N Chari
- Department of Physics, Central University of Karnataka, Aland Road, Kadaganchi, Kalaburagi, Karnataka, 585102, India
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2
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Regmi D, Shen F, Stanic A, Islam M, Du D. Effect of phospholipid liposomes on prion fragment (106-128) amyloid formation. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2023; 1865:184199. [PMID: 37454869 DOI: 10.1016/j.bbamem.2023.184199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 06/08/2023] [Accepted: 07/11/2023] [Indexed: 07/18/2023]
Abstract
Misfolding and aggregation of cellular prion protein (PrPc) is a major molecular process involved in the pathogenesis of prion diseases. Here, we studied the aggregation properties of a prion fragment peptide PrP(106-128). The results show that the peptide aggregates in a concentration-dependent manner in an aqueous solution and that the aggregation is sensitive to pH and the preformed amyloid seeds. Furthermore, we show that the zwitterionic POPC liposomes moderately inhibit the aggregation of PrP(106-128), whereas POPC/cholesterol (8:2) vesicles facilitate peptide aggregation likely due to the increase of the lipid packing order and membrane rigidity in the presence of cholesterol. In addition, anionic lipid vesicles of POPG and POPG/cholesterol above a certain concentration accelerate the aggregation of the peptide remarkably. The strong electrostatic interactions between the N-terminal region of the peptide and POPG may constrain the conformational plasticity of the peptide, preventing insertion of the peptide into the inner side of the membrane and thus promoting fibrillation on the membrane surface. The results suggest that the charge properties of the membrane, the composition of the liposomes, and the rigidity of lipid packing are critical in determining peptide adsorption on the membrane surface and the efficiency of the membrane in catalyzing peptide oligomeric nucleation and amyloid formation. The peptide could be used as an improved model molecule to investigate the mechanistic role of the crucial regions of PrP in aggregation in a membrane-rich environment and to screen effective inhibitors to block key interactions between these regions and membranes for preventing PrP aggregation.
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Affiliation(s)
- Deepika Regmi
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, FL 33431, USA
| | - Fengyun Shen
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, FL 33431, USA
| | - Aleksander Stanic
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, FL 33431, USA
| | - Majedul Islam
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, FL 33431, USA
| | - Deguo Du
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, FL 33431, USA.
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3
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Jabbari V, Sawczyk M, Amiri A, Král P, Shahbazian-Yassar R. Unveiling growth and dynamics of liposomes by graphene liquid cell-transmission electron microscopy. NANOSCALE 2023; 15:5011-5022. [PMID: 36790028 DOI: 10.1039/d2nr06147c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Liposome is a model system for biotechnological and biomedical purposes spanning from targeted drug delivery to modern vaccine research. Yet, the growth mechanism of liposomes is largely unknown. In this work, the formation and evolution of phosphatidylcholine-based liposomes are studied in real-time by graphene liquid cell-transmission electron microscopy (GLC-TEM). We reveal important steps in the growth, fusion and denaturation of phosphatidylcholine (PC) liposomes. We show that initially complex lipid aggregates resembling micelles start to form. These aggregates randomly merge while capturing water and forming small proto-liposomes. The nanoscopic containers continue sucking water until their membrane becomes convex and free of redundant phospholipids, giving stabilized PC liposomes of different sizes. In the initial stage, proto-liposomes grow at a rate of 10-15 nm s-1, which is followed by their growth rate of 2-5 nm s-1, limited by the lipid availability in the solution. Molecular dynamics (MD) simulations are used to understand the structure of micellar clusters, their evolution, and merging. The liposomes are also found to fuse through lipid bilayers docking followed by the formation of a hemifusion diaphragm and fusion pore opening. The liposomes denaturation can be described by initial structural destabilization and deformation of the membrane followed by the leakage of the encapsulated liquid. This study offers new insights on the formation and growth of lipid-based molecular assemblies which is applicable to a wide range of amphiphilic molecules.
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Affiliation(s)
- Vahid Jabbari
- Mechanical and Industrial Engineering Department, University of Illinois at Chicago, Chicago, IL 60607, USA. rsyassar@uic
| | - Michal Sawczyk
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Azadeh Amiri
- Mechanical and Industrial Engineering Department, University of Illinois at Chicago, Chicago, IL 60607, USA. rsyassar@uic
| | - Petr Král
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL 60607, USA
- Department of Physics, Pharmaceutical Sciences, and Chemical Engineering, University of Illinois at Chicago, Chicago, USA
| | - Reza Shahbazian-Yassar
- Mechanical and Industrial Engineering Department, University of Illinois at Chicago, Chicago, IL 60607, USA. rsyassar@uic
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4
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Doppler C, Messner B, Mimler T, Schachner B, Rezk M, Ganhör C, Wechselberger C, Müller M, Puh S, Pröll J, Arbeithuber B, Müller T, Zierer A, Bernhard D. Noncanonical atherosclerosis as the driving force in tricuspid aortic valve associated aneurysms - A trace collection. J Lipid Res 2023; 64:100338. [PMID: 36736622 PMCID: PMC10009546 DOI: 10.1016/j.jlr.2023.100338] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 01/08/2023] [Accepted: 01/19/2023] [Indexed: 02/04/2023] Open
Abstract
Pathogenic mechanisms in degenerative thoracic aortic aneurysms (TAA) are still unclear. There is an ongoing debate about whether TAAs are caused by uniform or distinct processes, which would obviously have a major impact on future treatment strategies. Clearly, the ultimate outcome of TAA subgroups associated with a tricuspid aortic valve (TAV) or a bicuspid aortic valve (BAV) is the same, namely a TAA. Based on results from our own and others' studies, we decided to compare the different TAAs (TAV and BAV) and controls using a broad array of analyses, i.e., metabolomic analyses, gene expression profiling, protein expression analyses, histological characterization, and matrix-assisted laser desorption ionization imaging. Central findings of the present study are the presence of noncanonical atherosclerosis, pathological accumulation of macrophages, and disturbances of lipid metabolism in the aortic media. Moreover, we have also found that lipid metabolism is impaired systemically. Importantly, all of the above-described phenotypes are characteristic for TAV-TAA only, and not for BAV-TAA. In summary, our results suggest different modes of pathogenesis in TAV- and BAV-associated aneurysms. Intimal atherosclerotic changes play a more central role in TAV-TAA formation than previously thought, particularly as the observed alterations do not follow classical patterns. Atherosclerotic alterations are not limited to the intima but also affect and alter the TAV-TAA media. Further studies are needed to i) clarify patho-relevant intima-media interconnections, ii) define the origin of the systemic alteration of lipid metabolism, and iii) to define valid biomarkers for early diagnosis, disease progression, and successful treatments in TAV-TAAs.
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Affiliation(s)
- Christian Doppler
- Division of Pathophysiology, Institute of Physiology and Pathophysiology, Medical Faculty, Johannes Kepler University Linz, Linz, Austria
| | - Barbara Messner
- Department of Cardiac Surgery, Cardiac Surgery Research Laboratory, Medical University of Vienna, Vienna, Austria
| | - Teresa Mimler
- Division of Pathophysiology, Institute of Physiology and Pathophysiology, Medical Faculty, Johannes Kepler University Linz, Linz, Austria; Department of Cardiac Surgery, Cardiac Surgery Research Laboratory, Medical University of Vienna, Vienna, Austria
| | - Bruno Schachner
- Department of Cardiothoracic and Vascular Surgery, Kepler University Hospital, Medical Faculty, Johannes Kepler University Linz, Linz, Austria
| | - Marlene Rezk
- Experimental Gynecology, Obstetrics and Gynecological Endocrinology, Kepler University Hospital Linz, Johannes Kepler University Linz, Linz, Austria
| | - Clara Ganhör
- Division of Pathophysiology, Institute of Physiology and Pathophysiology, Medical Faculty, Johannes Kepler University Linz, Linz, Austria
| | - Christian Wechselberger
- Division of Pathophysiology, Institute of Physiology and Pathophysiology, Medical Faculty, Johannes Kepler University Linz, Linz, Austria
| | - Marina Müller
- Division of Pathophysiology, Institute of Physiology and Pathophysiology, Medical Faculty, Johannes Kepler University Linz, Linz, Austria
| | - Spela Puh
- Division of Pathophysiology, Institute of Physiology and Pathophysiology, Medical Faculty, Johannes Kepler University Linz, Linz, Austria
| | - Johannes Pröll
- Center for Medical Research, Medical Faculty, Johannes Kepler University Linz, Linz, Austria
| | - Barbara Arbeithuber
- Experimental Gynecology, Obstetrics and Gynecological Endocrinology, Kepler University Hospital Linz, Johannes Kepler University Linz, Linz, Austria
| | - Thomas Müller
- Institute of Organic Chemistry, Faculty of Natural Sciences, Leopold-Franzens University Innsbruck, Innsbruck, Austria
| | - Andreas Zierer
- Department of Cardiothoracic and Vascular Surgery, Kepler University Hospital, Medical Faculty, Johannes Kepler University Linz, Linz, Austria
| | - David Bernhard
- Division of Pathophysiology, Institute of Physiology and Pathophysiology, Medical Faculty, Johannes Kepler University Linz, Linz, Austria; Center for Medical Research, Medical Faculty, Johannes Kepler University Linz, Linz, Austria.
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5
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Zykova VA, Surovtsev NV. Brillouin Spectroscopy of Binary Phospholipid-Cholesterol Bilayers. APPLIED SPECTROSCOPY 2022; 76:1206-1215. [PMID: 35712869 DOI: 10.1177/00037028221111147] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Multicomponent lipid bilayers are used as models for searching the origin of spatial heterogeneities in biomembranes called lipid rafts, implying the coexistence of domains of different phases and compositions within the lipid bilayer. The spatial organization of multicomponent lipid bilayers on a scale of a hundred nanometers remains unknown. Brillouin spectroscopy providing information about the acoustic phonons with the wavelength of several hundred nanometers has an unexplored potential for this problem. Here, we applied Brillouin spectroscopy for three binary bilayers composed of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), 1,2-palmitoyl-sn-glycero-3-phosphocholine (DPPC), and cholesterol. The Brillouin experiment for the oriented planar multibilayers was realized for two scattering geometries involving phonons for the lateral and normal directions of the propagation. The DPPC-DOPC mixtures known for the coexistence of the solid-ordered and liquid-disordered phases had bimodal Brillouin peaks, revealing the phase domains with sizes more than a hundred nanometers. Analysis of the Brillouin data for the binary mixtures concluded that the lateral phonons are preferable for testing the lateral homogeneity of the bilayers, while the phonons spreading across the bilayers are sensitive to the layered packing at the mesoscopic scale.
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Affiliation(s)
- Valeria A Zykova
- 104673Institute of Automation and Electrometry, Russian Academy of Sciences, Novosibirsk, Russia
| | - Nikolay V Surovtsev
- 104673Institute of Automation and Electrometry, Russian Academy of Sciences, Novosibirsk, Russia
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6
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The Ca 2+- and phospholipid-binding protein Annexin A2 is able to increase and decrease plasma membrane order. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2022; 1864:183810. [PMID: 34699769 DOI: 10.1016/j.bbamem.2021.183810] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 10/08/2021] [Accepted: 10/18/2021] [Indexed: 01/13/2023]
Abstract
Annexin A2 (AnxA2) is a calcium- and phospholipid-binding protein that plays roles in cellular processes involving membrane and cytoskeleton dynamics and is able to associate to several partner proteins. However, the principal molecular partners of AnxA2 are negatively charged phospholipids such as phosphatidylserine and phosphatidyl-inositol-(4,5)-phosphate. Herein we have studied different aspects of membrane lipid rearrangements induced by AnxA2 membrane binding. X-ray diffraction data revealed that AnxA2 has the property to stabilize lamellar structures and to block the formation of highly curved lipid phases (inverted hexagonal phase, HII). By using pyrene-labelled cholesterol and the environmental probe di-4-ANEPPDHQ, we observed that in model membranes, AnxA2 is able to modify both, cholesterol distribution and lipid compaction. In epithelial cells, we observed that AnxA2 localizes to membranes of different lipid order. The protein binding to membranes resulted in both, increases and/or decreases in membrane order depending on the cellular membrane regions. Overall, AnxA2 showed the capacity to modulate plasma membrane properties by inducing lipid redistribution that may lead to an increase in order or disorder of the membranes.
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7
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Tai P, Golding M, Singh H, Everett D. The bovine milk fat globule membrane – Liquid ordered domain formation and anticholesteremic effects during digestion. FOOD REVIEWS INTERNATIONAL 2022. [DOI: 10.1080/87559129.2021.2015773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- Patrick Tai
- Riddet Institute, Palmerston North, New Zealand
- School of Food and Advanced Technology, Massey University, Palmerston North, New Zealand
| | - Matt Golding
- Riddet Institute, Palmerston North, New Zealand
- School of Food and Advanced Technology, Massey University, Palmerston North, New Zealand
| | | | - David Everett
- Riddet Institute, Palmerston North, New Zealand
- Grasslands Research Centre, AgResearch, Palmerston North, New Zealand
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8
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Li YS, Wang YT, Tseng WL, Lu CY. Peptide-based chiral derivatizing reagents in nano-scale liquid chromatography: Effect of the oxidation state of cysteine moiety on enantioseparation of ibuprofen. Microchem J 2022. [DOI: 10.1016/j.microc.2021.106933] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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9
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Surovtsev NV, Adichtchev SV. Dynamic response on a nanometer scale of binary phospholipid-cholesterol vesicles: Low-frequency Raman scattering insight. Phys Rev E 2021; 104:054406. [PMID: 34942765 DOI: 10.1103/physreve.104.054406] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 10/18/2021] [Indexed: 11/07/2022]
Abstract
Low-frequency Raman spectroscopy was used to study the dynamic response on a nanometer scale of aqueous suspensions of two-component lipid vesicles. Binary mixtures of saturated phospholipid (1,2-dipalmitoyl-sn-glycero-3-phosphocholine, DPPC) and cholesterol are interesting for possible coexistence of solidlike and liquid-ordered phases, while the phase coexistence was not reported for unsaturated phospholipid (1,2-dioleoyl-sn-glycero-3-phosphocholine, DOPC) and cholesterol mixtures. The DOPC-DPPC mixtures represent the well-documented case of coexisting domains of solidlike and liquid-disordered phases. These three series of lipid mixtures are studied here. A broad peak with the maximum in the range of 30-50cm^{-1} and a narrow peak near 10cm^{-1} are observed in the Raman susceptibility of the binary mixtures and attributed to the acousticlike vibrational density of states and layer modes, respectively. Parameters of the broad and narrow peaks are sensitive to lateral and conformational hydrocarbon chain ordering. It was also demonstrated that the low-frequency Raman susceptibility of multicomponent lipid bilayers allows one to determine the phase state of lipid bilayers and distinguish the homogeneous distribution of molecular complexes from coexisting domains with sizes above several nanometers. Thus, the low-frequency Raman spectroscopy provides unique information in studying phase coexistence in lipid bilayers.
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Affiliation(s)
- N V Surovtsev
- Institute of Automation and Electrometry, Russian Academy of Sciences, Novosibirsk 630090, Russia
| | - S V Adichtchev
- Institute of Automation and Electrometry, Russian Academy of Sciences, Novosibirsk 630090, Russia
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10
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Presence of Cholesterol in Non-Animal Organisms: Identification and Quantification of Cholesterol in Crude Seed Oil from Perilla frutescens and Dehydrated Pyropia tenera. Molecules 2021; 26:molecules26123767. [PMID: 34205624 PMCID: PMC8234223 DOI: 10.3390/molecules26123767] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 06/17/2021] [Accepted: 06/18/2021] [Indexed: 11/23/2022] Open
Abstract
Studies have reported that cholesterol, a molecule found mainly in animals, is also present in some plants and algae. This study aimed to determine whether cholesterol exists in three dehydrated algae species, namely, Pyropia tenera, Saccharina japonica, and Undaria pinnatifida, and in one plant species, namely, Perilla frutescens (four perilla seed oil samples were analyzed). These species were chosen for investigation because they are common ingredients in East Asian cuisine. Gas chromatography-flame ionization detection (GC-FID) analysis found that cholesterol was present in P. tenera (14.6 mg/100 g) and in all four perilla seed oil samples (0.3–0.5 mg/100 g). High-performance liquid chromatography with evaporative light-scattering detection (HPLC-ELSD) also demonstrated that cholesterol was present in P. tenera (14.2 mg/100 g) and allowed the separation of cholesterol from its isomer lathosterol. However, cholesterol could not be detected by HPLC-ELSD in the perilla seed oil samples, most likely because it is only present in trace amounts. Moreover, liquid chromatography-tandem mass spectrometry (LC-MS/MS) confirmed the presence of cholesterol in both P. tenera and perilla seed oil. MRM results further suggested that lathosterol (a precursor of cholesterol) was present in P. tenera.
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11
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Rowlands LJ, Marks A, Sanderson JM, Law RV. 17O NMR spectroscopy as a tool to study hydrogen bonding of cholesterol in lipid bilayers. Chem Commun (Camb) 2021; 56:14499-14502. [PMID: 33150883 DOI: 10.1039/d0cc05466f] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Cholesterol is a crucial component of biological membranes and can interact with other membrane components through hydrogen bonding. NMR spectroscopy has been used previously to investigate this bonding, however this study represents the first 17O NMR spectroscopy study of isotopically enriched cholesterol. We demonstrate the 17O chemical shift is dependent on hydrogen bonding, providing a novel method for the study of cholesterol in bilayers.
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Affiliation(s)
- Lucy J Rowlands
- Institute of Chemical Biology, Imperial College London, Molecular Sciences Research Hub, W12 0BZ London, UK.
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12
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Cholesterol-phospholipid interactions resist the detergent effect of bovine bile. Colloids Surf B Biointerfaces 2021; 205:111842. [PMID: 34022699 DOI: 10.1016/j.colsurfb.2021.111842] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 05/02/2021] [Accepted: 05/08/2021] [Indexed: 12/29/2022]
Abstract
Sphingomyelin (SM) and cholesterol complexation gives rise to detergent-resistant liquid-ordered domains. The persistence of these domains and subsequent mixed micelle formation was examined in the presence of bile under physiological digestive in vitro conditions for vesicles comprising either SM/cholesterol, porcine brain phosphatidylcholine (BPC)/cholesterol, or soy phosphatidylcholine (SPC)/cholesterol bilayers, the latter two systems having no liquid-ordered domains. Micellization of these digested phospholipid multilamellar vesicle systems was confirmed by transmission electron microscopy. Bovine bile was found to consist of large multilamellar sheets which subsumed phospholipid vesicles to form aggregated superstructures. Budding off from these superstructures were vesicle-to-micelle transition intermediates: unilamellar vesicles and cylindrical micelles. The presence of cholesterol (60/40 phospholipid/cholesterol mol/mol) delayed the initial rapid onset of digestion, but not for BPC and SPC vesicle systems. Acyl chain order/disorder before and after vesicle-to-micelle transition of all three phospholipid/cholesterol systems was examined using Raman spectroscopy. The addition of bovine bile to both PC/cholesterol vesicle systems reduced the overall ratio of acyl chain disorder to order. In SM/cholesterol vesicles with ≤ 20% mol cholesterol, only the lateral inter-acyl chain packing was reduced, whereas for SM/cholesterol vesicles with ≥ 30% mol cholesterol, a higher proportion of gauche-to-trans isomerization was apparent, demonstrating that SM/cholesterol complexes modify the acyl chain structure of micelles.
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13
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Feng Y, Zhang Y, Liu G, Liu X, Gao S. Interaction of graphene oxide with artificial cell membranes: Role of anionic phospholipid and cholesterol in nanoparticle attachment and membrane disruption. Colloids Surf B Biointerfaces 2021; 202:111685. [PMID: 33721805 DOI: 10.1016/j.colsurfb.2021.111685] [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: 12/06/2020] [Revised: 03/01/2021] [Accepted: 03/06/2021] [Indexed: 11/30/2022]
Abstract
A mechanistic understanding of the interaction of graphene oxide (GO) with cell membranes is critical for predicting the biological effects of GO following accidental exposure and biomedical applications. We herein used a quartz crystal microbalance with dissipation monitoring (QCM-D) to probe the interaction of GO with model cell membranes modified with anionic lipids or cholesterol under biologically relevant conditions. The attachment efficiency of GO on supported lipid bilayers (SLBs) decreased with increasing anionic lipid content and was unchanged with varying cholesterol content. In addition, the incorporation of anionic lipids to the SLBs rendered the attachment of GO partially reversible upon a decrease in solution ionic strength. These results demonstrate the critical role of lipid bilayer surface charge in controlling GO attachment and release. We also employed the fluorescent dye leakage technique to quantify the role of anionic lipids and cholesterol in vesicle disruption caused by GO. Notably, we observed a linear correlation between the amount of dye leakage from the vesicles and the attachment efficiencies of GO on the SLBs, confirming that membrane disruption is preceded by GO attachment. This study highlights the non-negligible role of lipid bilayer composition in controlling the physicochemical interactions between cell membranes and GO.
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Affiliation(s)
- Yiping Feng
- Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China; Department of Environmental Health and Engineering, Johns Hopkins University, Baltimore, MD 21218-2686, United States; State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu 210023, China.
| | - Yijian Zhang
- Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
| | - Guoguang Liu
- Guangzhou Key Laboratory Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, Guangzhou 510006, China
| | - Xitong Liu
- Department of Civil and Environmental Engineering, The George Washington University, Washington, D.C. 20052, United States.
| | - Shixiang Gao
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu 210023, China
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14
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Bhuyan NN, Pattnaik GP, Mishra A, Chakraborty H. Exploring membrane viscosity at the headgroup region utilizing a hemicyanine-based fluorescent probe. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2020.115152] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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15
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Pedroni VI, Sierra MB, Alarcón LM, Verde AR, Appignanesi GA, Morini MA. A certain proportion of docosahexaenoic acid tends to revert structural and dynamical effects of cholesterol on lipid membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2021; 1863:183584. [PMID: 33571481 DOI: 10.1016/j.bbamem.2021.183584] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Revised: 01/29/2021] [Accepted: 02/05/2021] [Indexed: 12/19/2022]
Abstract
This work investigates how docosahexaenoic acid (DHA) modifies the effect of Cholesterol (Chol) on the structural and dynamical properties of dipalmitoylphosphatidylcholine (DPPC) membrane. We employ low-cost and non-invasive methods: zeta potential (ZP), conductivity, density, and ultrasound velocity, complemented by molecular dynamics simulations. Our studies reveal that 30% of DHA added to the DPPC-Chol system tends to revert Chol action on a model lipid bilayer. Results obtained in this work shed light on the effect of polyunsaturated fatty acids - particularly DHA - on lipid membranes, with potential preventive applications in many diseases, e.g. neuronal as, Alzheimer's disease, and viral, as Covid-19.
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Affiliation(s)
- V I Pedroni
- Laboratorio de Fisicoquímica, INQUISUR, Departamento de Química, Universidad Nacional del Sur (UNS)-CONICET, Av. Alem 1253, 8000 Bahía Blanca, Buenos Aires, Argentina
| | - M B Sierra
- Laboratorio de Fisicoquímica, INQUISUR, Departamento de Química, Universidad Nacional del Sur (UNS)-CONICET, Av. Alem 1253, 8000 Bahía Blanca, Buenos Aires, Argentina
| | - L M Alarcón
- Laboratorio de Fisicoquímica, INQUISUR, Departamento de Química, Universidad Nacional del Sur (UNS)-CONICET, Av. Alem 1253, 8000 Bahía Blanca, Buenos Aires, Argentina
| | - A R Verde
- Laboratorio de Fisicoquímica, INQUISUR, Departamento de Química, Universidad Nacional del Sur (UNS)-CONICET, Av. Alem 1253, 8000 Bahía Blanca, Buenos Aires, Argentina
| | - G A Appignanesi
- Laboratorio de Fisicoquímica, INQUISUR, Departamento de Química, Universidad Nacional del Sur (UNS)-CONICET, Av. Alem 1253, 8000 Bahía Blanca, Buenos Aires, Argentina
| | - M A Morini
- Laboratorio de Fisicoquímica, INQUISUR, Departamento de Química, Universidad Nacional del Sur (UNS)-CONICET, Av. Alem 1253, 8000 Bahía Blanca, Buenos Aires, Argentina.
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16
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Lewicky JD, Fraleigh NL, Boraman A, Martel AL, Nguyen TMD, Schiller PW, Shiao TC, Roy R, Montaut S, Le HT. Mannosylated glycoliposomes for the delivery of a peptide kappa opioid receptor antagonist to the brain. Eur J Pharm Biopharm 2020; 154:290-296. [PMID: 32717389 DOI: 10.1016/j.ejpb.2020.07.021] [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] [Received: 11/04/2019] [Revised: 06/03/2020] [Accepted: 07/21/2020] [Indexed: 10/23/2022]
Abstract
Dynantin is a potent and selective synthetic polypeptide kappa opioid receptor antagonist which has potential antidepressant and anxiolytic-like therapeutic applications, however its clinical development has been hampered by plasma stability issues and poor penetration of the blood brain barrier. Targeted liposome delivery systems represent a promising and non-invasive approach to improving the delivery of therapeutic agents across the blood brain barrier. As part of our work focused on targeted drug delivery, we have developed a novel mannosylated liposome system. Herein, we investigate these glycoliposomes for the targeted delivery of dynantin to the central nervous system. Cholesterol was tested and optimized as a formulation excipient, where it improved particle stability as measured via particle size, entrapment and ex vivo plasma stability of dynantin. The in vitro PRESTO-TANGO assay system was used to confirm that glycoliposomal entrapment did not impact the affinity or activity of the peptide at its receptor. Finally, in vivo distribution studies in mice showed that the mannosylated glycoliposomes significantly improved delivery of dynantin to the brain. Overall, the results clearly demonstrate the potential of our glycoliposomes as a targeted delivery system for therapeutic agents of the central nervous system.
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Affiliation(s)
- Jordan D Lewicky
- Health Sciences North Research Institute, 56 Walford Road, Sudbury, Ontario P3E 2H2, Canada
| | - Nya L Fraleigh
- Health Sciences North Research Institute, 56 Walford Road, Sudbury, Ontario P3E 2H2, Canada
| | - Amanda Boraman
- Health Sciences North Research Institute, 56 Walford Road, Sudbury, Ontario P3E 2H2, Canada; Department of Chemistry and Biochemistry, Laurentian University, 935 Ramsey Lake Road, Sudbury, Ontario P3E 2C6, Canada
| | - Alexandrine L Martel
- Health Sciences North Research Institute, 56 Walford Road, Sudbury, Ontario P3E 2H2, Canada
| | - Thi M-D Nguyen
- Laboratory of Chemical Biology and Peptide Research, Clinical Research Institute of Montreal, 110 Pine Avenue W, Montreal, Quebec H2W 1R7, Canada
| | - Peter W Schiller
- Laboratory of Chemical Biology and Peptide Research, Clinical Research Institute of Montreal, 110 Pine Avenue W, Montreal, Quebec H2W 1R7, Canada; Department of Pharmacology and Physiology, University of Montreal, 2900 Boulevard Édouard-Montpetit, Montreal, Quebec H3T 1J4, Canada
| | - Tze Chieh Shiao
- Department of Chemistry, Université du Québec à Montréal, Montreal, Quebec H3C 3P8, Canada
| | - René Roy
- Department of Chemistry, Université du Québec à Montréal, Montreal, Quebec H3C 3P8, Canada
| | - Sabine Montaut
- Department of Chemistry and Biochemistry, Laurentian University, 935 Ramsey Lake Road, Sudbury, Ontario P3E 2C6, Canada; Biomolecular Sciences Programme, Laurentian University, Subdury, Ontario, Canada
| | - Hoang-Thanh Le
- Health Sciences North Research Institute, 56 Walford Road, Sudbury, Ontario P3E 2H2, Canada; Department of Chemistry and Biochemistry, Laurentian University, 935 Ramsey Lake Road, Sudbury, Ontario P3E 2C6, Canada; Northern Ontario School of Medicine, Medicinal Sciences Division, 935 Ramsey Lake Road, Sudbury, Ontario P3E 2C6, Canada; Department of Biology, Laurentian University, 935 Ramsey Lake Road, Sudbury, Ontario P3E 2C6, Canada.
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17
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Bui TT, Suga K, Umakoshi H. Ergosterol-Induced Ordered Phase in Ternary Lipid Mixture Systems of Unsaturated and Saturated Phospholipid Membranes. J Phys Chem B 2019; 123:6161-6168. [DOI: 10.1021/acs.jpcb.9b03413] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Tham Thi Bui
- Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama-cho, Toyonaka, Osaka 560-8531, Japan
| | - Keishi Suga
- Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama-cho, Toyonaka, Osaka 560-8531, 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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18
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Ha JH, Jeong YJ, Kim AY, Hong IK, Lee NH, Park SN. Preparation and Physicochemical Properties of a Cysteine Derivative‐Loaded Deformable Liposomes in Hydrogel for Enhancing Whitening Effects. EUR J LIPID SCI TECH 2018. [DOI: 10.1002/ejlt.201800125] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Ji Hoon Ha
- Department of Fine ChemistryNanobiocosmetic Laboratory and Cosmetic R&D CenterSeoul National University of Science and Technology232 Gongneung‐roNowon‐guSeoul01811Republic of Korea
| | - Yun Ju Jeong
- Department of Fine ChemistryNanobiocosmetic Laboratory and Cosmetic R&D CenterSeoul National University of Science and Technology232 Gongneung‐roNowon‐guSeoul01811Republic of Korea
| | - A Young Kim
- Department of Fine ChemistryNanobiocosmetic Laboratory and Cosmetic R&D CenterSeoul National University of Science and Technology232 Gongneung‐roNowon‐guSeoul01811Republic of Korea
| | - In Ki Hong
- Department of Fine ChemistryNanobiocosmetic Laboratory and Cosmetic R&D CenterSeoul National University of Science and Technology232 Gongneung‐roNowon‐guSeoul01811Republic of Korea
| | - Nan Hee Lee
- Department of Fine ChemistryNanobiocosmetic Laboratory and Cosmetic R&D CenterSeoul National University of Science and Technology232 Gongneung‐roNowon‐guSeoul01811Republic of Korea
| | - Soo Nam Park
- Department of Fine ChemistryNanobiocosmetic Laboratory and Cosmetic R&D CenterSeoul National University of Science and Technology232 Gongneung‐roNowon‐guSeoul01811Republic of Korea
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19
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Stereospecific Interactions of Cholesterol in a Model Cell Membrane: Implications for the Membrane Dipole Potential. J Membr Biol 2018; 251:507-519. [DOI: 10.1007/s00232-018-0016-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 01/25/2018] [Indexed: 12/11/2022]
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20
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Nitsche JM, Kasting GB. A Universal Correlation Predicts Permeability Coefficients of Fluid- and Gel-Phase Phospholipid and Phospholipid-Cholesterol Bilayers for Arbitrary Solutes. J Pharm Sci 2017; 105:1762-1771. [PMID: 27112406 DOI: 10.1016/j.xphs.2016.02.012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 01/26/2016] [Accepted: 02/02/2016] [Indexed: 11/24/2022]
Abstract
The permeability of gel-phase phospholipids is typically about an order of magnitude lower than that of the same compositions in the fluid phase, yet a quantitative description of the ordering factors leading to this difference has been elusive. The present analysis examines these factors with particular focus on the area per phospholipid chain, Ac, and its relationship to the minimum area per molecule in the crystalline state, A0. It is shown that fluid- and gel-phase phospholipid permeabilities can be reconciled by postulating a minimum area per chain Ac,0 = 17.1 Å(2), substantially less than one would estimate by dividing the accepted value A0 = 40.8 Å(2) by 2. An extended data set of phospholipid and phospholipid-cholesterol bilayer permeability data extending over 9 orders of magnitude is analyzed and correlated according to the developed relationship (N = 85, s = 0.3024, r(2) = 0.9332). Individual permeability values are consequently predicted to within an average deviation of 10(0.3024) or about a factor of 2. The analysis is broadly applicable in the fluid phase but is restricted to gel-phase phospholipid compositions that do not contain cholesterol. Guidance for the latter scenario is provided.
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Affiliation(s)
- Johannes M Nitsche
- Department of Chemical and Biological Engineering, University at Buffalo, The State University of New York, Buffalo, New York 14260-4200.
| | - Gerald B Kasting
- James L. Winkle College of Pharmacy, University of Cincinnati Academic Health Center, Cincinnati, Ohio 45267-0004
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21
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Bandara A, Panahi A, Pantelopulos GA, Straub JE. Exploring the structure and stability of cholesterol dimer formation in multicomponent lipid bilayers. J Comput Chem 2017; 38:1479-1488. [PMID: 27761918 PMCID: PMC5398962 DOI: 10.1002/jcc.24516] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Revised: 09/27/2016] [Accepted: 09/30/2016] [Indexed: 01/13/2023]
Abstract
For 40 years, the existence and possible functional importance of cholesterol dimer formation has been discussed. Due to challenges associated with structural studies of membrane lipids, there has as yet been no direct experimental verification of the existence and relevance of the cholesterol dimer. Building on recent advances in lipid force fields for molecular simulation, in this work the structure and stability of the cholesterol dimer is characterized in POPC bilayers in absence and presence of sphingomyelin. The cholesterol dimer structural ensemble is found to consist of sub-states that reflect, but also differ from, previously proposed dimer structures. While face-to-face dimer structures predominate, no evidence is found for the existence of tail-to-tail dimers in POPC lipid bilayers. Near stoichiometric complex formation of cholesterol with sphingomyelin is found to effect cholesterol dimer structure without impacting population. Comparison with NMR-derived order parameters provide validation for the simulation model employed and conclusions drawn related to the structure and stability of cholesterol dimers in multicomponent lipid bilayers. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Asanga Bandara
- Department of Chemistry, Boston University, 590 Commonwealth Ave., Boston, Massachusetts, 02215, United States
| | - Afra Panahi
- Department of Chemistry, Boston University, 590 Commonwealth Ave., Boston, Massachusetts, 02215, United States
| | - George A. Pantelopulos
- Department of Chemistry, Boston University, 590 Commonwealth Ave., Boston, Massachusetts, 02215, United States
| | - John E. Straub
- Department of Chemistry, Boston University, 590 Commonwealth Ave., Boston, Massachusetts, 02215, United States
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22
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Magnetic nanoparticles coated with polyarabic acid demonstrate enhanced drug delivery and imaging properties for cancer theranostic applications. Sci Rep 2017; 7:775. [PMID: 28396592 PMCID: PMC5429723 DOI: 10.1038/s41598-017-00836-y] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Accepted: 03/10/2017] [Indexed: 01/11/2023] Open
Abstract
Therapeutic targeting of tumor cells with drug nanocarriers relies upon successful interaction with membranes and efficient cell internalization. A further consideration is that engineered nanomaterials should not damage healthy tissues upon contact. A critical factor in this process is the external coating of drug delivery nanodevices. Using in silico, in vitro and in vivo studies, we show for the first time that magnetic nanoparticles coated with polyarabic acid have superior imaging, therapeutic, and biocompatibility properties. We demonstrate that polyarabic acid coating allows for efficient penetration of cell membranes and internalization into breast cancer cells. Polyarabic acid also allows reversible loading of the chemotherapeutic drug Doxorubicin, which upon release suppresses tumor growth in vivo in a mouse model of breast cancer. Furthermore, these nanomaterials provide in vivo contrasting properties, which directly compare with commercial gadolinium-based contrasting agents. Finally, we report excellent biocompatibility, as these nanomaterial cause minimal, if any cytotoxicity in vitro and in vivo. We thus propose that magnetic nanodevices coated with polyarabic acid offer a new avenue for theranostics efforts as efficient drug carriers, while providing excellent contrasting properties due to their ferrous magnetic core, which can help the future design of nanomaterials for cancer imaging and therapy.
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23
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Tai K, He X, Yuan X, Meng K, Gao Y, Yuan F. A comparison of physicochemical and functional properties of icaritin-loaded liposomes based on different surfactants. Colloids Surf A Physicochem Eng Asp 2017. [DOI: 10.1016/j.colsurfa.2017.01.019] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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24
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Belička M, Weitzer A, Pabst G. High-resolution structure of coexisting nanoscopic and microscopic lipid domains. SOFT MATTER 2017; 13:1823-1833. [PMID: 28170020 DOI: 10.1039/c6sm02727j] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
We studied coexisting micro- and nanoscopic liquid-ordered/liquid-disordered domains in fully hydrated multilamellar vesicles using small-angle X-ray scattering. Large domains exhibited long-range out-of-plane positional correlations of like domains, consistent with previous reports. In contrast, such correlations were absent in nanoscopic domains. Advancing a global analysis of the in situ data allowed us to gain a deep insight into the structural and elastic properties of the coexisting domains, including the partitioning of cholesterol in each domain. In agreement with a previous report, we found that the thickness mismatch between ordered and disordered domains decreased for nanoscopic domains. At the same time, we found also the lipid packing mismatch to be decreased for nano-domains, mainly due to the liquid-disordered domains becoming more densely packed when decreasing their size.
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Affiliation(s)
- Michal Belička
- University of Graz, Institute of Molecular Biosciences, Biophysics Division, NAWI Graz, Humboldtstr. 50/III, A-8010 Graz, Austria. and BioTechMed-Graz, A-8010 Graz, Austria
| | - Anna Weitzer
- University of Graz, Institute of Molecular Biosciences, Biophysics Division, NAWI Graz, Humboldtstr. 50/III, A-8010 Graz, Austria. and BioTechMed-Graz, A-8010 Graz, Austria
| | - Georg Pabst
- University of Graz, Institute of Molecular Biosciences, Biophysics Division, NAWI Graz, Humboldtstr. 50/III, A-8010 Graz, Austria. and BioTechMed-Graz, A-8010 Graz, Austria
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25
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Strømland Ø, Handegård ØS, Govasli ML, Wen H, Halskau Ø. Peptides derived from α-lactalbumin membrane binding helices oligomerize in presence of lipids and disrupt bilayers. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2017; 1859:1029-1039. [PMID: 28069414 DOI: 10.1016/j.bbamem.2017.01.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2016] [Revised: 12/02/2016] [Accepted: 01/04/2017] [Indexed: 11/16/2022]
Abstract
Helix A and -C of α-lactalbumin, a loosely folded amphitropic protein, perturb lipid monolayers by the formation of amyloid pore-like structures. To investigate whether these helices are able to disrupt fully formed bilayers, we designed peptides comprised of Helix A and -C, and investigated their membrane-perturbing properties. The peptides, designated A-Cage-C and A-Lnk-C, were prepared with tryptophan sites in the helical and the spacer segments in order to monitor which part were involved in membrane association under given conditions. The peptides associate with and disrupt negatively charged bilayers in a pH-dependent manner and α-helical tendencies increased upon membrane association. Both helices and the spacer segment were involved in membrane binding in the case of A-Lnk-C, and there are indications that the two helixes act in synergy to affect the membrane. However, the helices and the spacer segment could not intercalate when present as A-Cage-C at neutral conditions. At acidic pH, both helices could intercalate, but not the central spacer segment. AFM performed on bilayers under aqueous conditions revealed oligomers formed by the peptides. The presence of bilayers and acidic pHs were both drivers for the formation of these, suggestive of models for peptide oligomerization where segments of the peptide are stacked in an electrostatically favorable manner by the surface. Of the two peptides, A-Lnk-C was the more prolific oligomerizer, and also formed amyloid-fibril like structures at acidic pH and elevated concentrations. Our results suggest the peptides perturb membranes not through pore-like structures, but possibly by a thinning mechanism.
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Affiliation(s)
- Øyvind Strømland
- Department of Molecular Biology, University of Bergen, Thormøhlensgt. 55, 5008 Bergen, Norway
| | - Ørjan S Handegård
- Department of Molecular Biology, University of Bergen, Thormøhlensgt. 55, 5008 Bergen, Norway
| | - Morten L Govasli
- Department of Molecular Biology, University of Bergen, Thormøhlensgt. 55, 5008 Bergen, Norway
| | - Hanzhen Wen
- Department of Molecular Biology, University of Bergen, Thormøhlensgt. 55, 5008 Bergen, Norway
| | - Øyvind Halskau
- Department of Molecular Biology, University of Bergen, Thormøhlensgt. 55, 5008 Bergen, Norway.
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26
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Marquardt D, Heberle FA, Greathouse DV, Koeppe RE, Standaert RF, Van Oosten BJ, Harroun TA, Kinnun JJ, Williams JA, Wassall SR, Katsaras J. Lipid bilayer thickness determines cholesterol's location in model membranes. SOFT MATTER 2016; 12:9417-9428. [PMID: 27801465 DOI: 10.1039/c6sm01777k] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Cholesterol is an essential biomolecule of animal cell membranes, and an important precursor for the biosynthesis of certain hormones and vitamins. It is also thought to play a key role in cell signaling processes associated with functional plasma membrane microdomains (domains enriched in cholesterol), commonly referred to as rafts. In all of these diverse biological phenomena, the transverse location of cholesterol in the membrane is almost certainly an important structural feature. Using a combination of neutron scattering and solid-state 2H NMR, we have determined the location and orientation of cholesterol in phosphatidylcholine (PC) model membranes having fatty acids of different lengths and degrees of unsaturation. The data establish that cholesterol reorients rapidly about the bilayer normal in all the membranes studied, but is tilted and forced to span the bilayer midplane in the very thin bilayers. The possibility that cholesterol lies flat in the middle of bilayers, including those made from PC lipids containing polyunsaturated fatty acids (PUFAs), is ruled out. These results support the notion that hydrophobic thickness is the primary determinant of cholesterol's location in membranes.
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Affiliation(s)
- Drew Marquardt
- Department of Physics, Brock University, St. Catharines, Ontario L2S 3A1, Canada and Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Frederick A Heberle
- The Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, Tennessee 37996, USA and Joint Institute for Biological Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA and Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
| | - Denise V Greathouse
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, Arkansas 72701, USA
| | - Roger E Koeppe
- Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, Arkansas 72701, USA
| | - Robert F Standaert
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA and Department of Biochemistry and Cellular & Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Brad J Van Oosten
- Department of Physics, Brock University, St. Catharines, Ontario L2S 3A1, Canada
| | - Thad A Harroun
- Department of Physics, Brock University, St. Catharines, Ontario L2S 3A1, Canada
| | - Jacob J Kinnun
- Department of Physics, Indiana University - Purdue University Indianapolis, Indianapolis, Indiana 46202, USA.
| | - Justin A Williams
- Department of Physics, Indiana University - Purdue University Indianapolis, Indianapolis, Indiana 46202, USA.
| | - Stephen R Wassall
- Department of Physics, Indiana University - Purdue University Indianapolis, Indianapolis, Indiana 46202, USA.
| | - John Katsaras
- Department of Physics, Brock University, St. Catharines, Ontario L2S 3A1, Canada and The Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, Tennessee 37996, USA and Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA. and Shull Wollan Center-a Joint Institute for Neutron Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA and Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996, USA
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27
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Yamada A, Shimizu N, Hikima T, Takata M, Kobayashi T, Takahashi H. Effect of Cholesterol on the Interaction of Cytochrome P450 Substrate Drug Chlorzoxazone with the Phosphatidylcholine Bilayer. Biochemistry 2016; 55:3888-98. [DOI: 10.1021/acs.biochem.6b00286] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Ayumi Yamada
- Biophysics
Laboratory, Division of Pure and Applied Science, Graduate School
of Science and Technology, Gunma University, 4-2 Aramaki, Maebashi, Gunma 371-8510, Japan
| | - Nobutaka Shimizu
- Photon
Factory, Institute of Materials Structure Science, High Energy Accelerator Research Organization, 1-1 Oho, Tsukuba, Ibaraki 305-0801, Japan
| | - Takaaki Hikima
- RIKEN SPring-8 Center, 1-1-1
Kouto, Sayo, Hyougo 679-5148, Japan
| | - Masaki Takata
- RIKEN SPring-8 Center, 1-1-1
Kouto, Sayo, Hyougo 679-5148, Japan
- Institute
of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1
Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
| | - Toshihide Kobayashi
- Lipid
Biology Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Hiroshi Takahashi
- Biophysics
Laboratory, Division of Pure and Applied Science, Graduate School
of Science and Technology, Gunma University, 4-2 Aramaki, Maebashi, Gunma 371-8510, Japan
- RIKEN SPring-8 Center, 1-1-1
Kouto, Sayo, Hyougo 679-5148, Japan
- Lipid
Biology Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
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28
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Strømland Ø, Jakubec M, Furse S, Halskau Ø. Detection of misfolded protein aggregates from a clinical perspective. J Clin Transl Res 2016; 2:11-26. [PMID: 30873457 PMCID: PMC6410640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Revised: 03/22/2016] [Accepted: 03/22/2016] [Indexed: 11/29/2022] Open
Abstract
Neurodegenerative Protein Misfolding Diseases (PMDs), such as Alzheimer's (AD), Parkinson's (PD) and prion diseases, are generally difficult to diagnose before irreversible damage to the central nervous system damage has occurred. Detection of the misfolded proteins that ultimately lead to these conditions offers a means for providing early detection and diagnosis of this class of disease. In this review, we discuss recent developments surrounding protein misfolding diseases with emphasis on the cytotoxic oligomers implicated in their aetiology. We also discuss the relationship of misfolded proteins with biological membranes. Finally, we discuss how far techniques for providing early diagnoses for PMDs have advanced and describe promising clinical approaches. We conclude that antibodies with specificity towards oligomeric species of AD and PD and lectins with specificity for particular glycosylation, show promise. However, it is not clear which approach may yield a reliable clinical test first. Relevance for patients: Individuals suffering from protein misfolding diseases will likely benefit form earlier, less- or even non-invasive diagnosis techniques. The current state and possible future directions for these are subject of this review.
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29
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30
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Alwarawrah M, Hussain F, Huang J. Alteration of lipid membrane structure and dynamics by diacylglycerols with unsaturated chains. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1858:253-63. [PMID: 26607007 DOI: 10.1016/j.bbamem.2015.11.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 11/05/2015] [Accepted: 11/18/2015] [Indexed: 01/15/2023]
Abstract
Diacylglycerols (DAGs) with unsaturated acyl chains play many important roles in biomembranes, such as a second messenger and activator for protein kinase C. In this study, three DAGs of distinctly different chain unsaturations (i.e. di16:0DAG (DPG), 16:0-18:1DAG (POG), and di18:1DAG (DOG)) are studied using atomistic MD simulation to compare their roles in the structure and dynamics of 16:0-18:1phosphatidylcholine (POPC) membranes. All three DAGs are able to produce the so-called 'condensing effect' in POPC membranes: decreasing area-per-lipid, and increasing acyl chain order and bilayer thickness. Our visual and quantitative analyses clearly show that DAG with unsaturated chains induce larger spacing between POPC headgroups, compared with DAG with saturated chains; this particular effect has long been hypothesized to be crucial for activating enzymes and receptors in cell membranes. DAGs with unsaturated chains are also located closer to the bilayer/aqueous interface than DPG and are more effective in slowing down lateral diffusion of molecules. We show that DAG molecules seek the "umbrella coverage" from neighboring phospholipid headgroups - similar to cholesterol. Unlike cholesterol, DAGs also hide their chains from water by laterally inserting their chains into the surrounding. Thus, acyl chains of DAG are more spread and disordered than those of PC due to the insertion. By calculating the potential of mean force (PMF) for POPC in POPC/DAG bilayers, we found that all three DAGs can significantly increase the free energy barrier for POPC to flip-flop, but only DAGs with unsaturated chains can additionally increase the free energy of POPC desorption.
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Affiliation(s)
- Mohammad Alwarawrah
- Department of Physics, Texas Tech University, Lubbock, TX 79409, United States
| | - Fazle Hussain
- Department of Mechanical Engineering, Texas Tech University, Lubbock, TX 79409, United States
| | - Juyang Huang
- Department of Physics, Texas Tech University, Lubbock, TX 79409, United States.
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31
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Serum levels of free T3 are associated with ApoA1 and ApoA2, whereas free T4 levels are associated with ApoB and LDL-cholesterol in euthyroid cardiovascular patients. ACTA ACUST UNITED AC 2015. [DOI: 10.1016/j.ijcme.2015.04.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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32
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Kwolek U, Kulig W, Wydro P, Nowakowska M, Róg T, Kepczynski M. Effect of Phosphatidic Acid on Biomembrane: Experimental and Molecular Dynamics Simulations Study. J Phys Chem B 2015; 119:10042-51. [DOI: 10.1021/acs.jpcb.5b03604] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Urszula Kwolek
- Faculty
of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Kraków, Poland
| | - Waldemar Kulig
- Department
of Physics, Tampere University of Technology, P.O. Box 692, FI-33101 Tampere, Finland
| | - Paweł Wydro
- Faculty
of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Kraków, Poland
| | - Maria Nowakowska
- Faculty
of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Kraków, Poland
| | - Tomasz Róg
- Department
of Physics, Tampere University of Technology, P.O. Box 692, FI-33101 Tampere, Finland
| | - Mariusz Kepczynski
- Faculty
of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Kraków, Poland
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33
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Hong C, Tieleman DP, Wang Y. Microsecond molecular dynamics simulations of lipid mixing. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:11993-2001. [PMID: 25237736 PMCID: PMC4196744 DOI: 10.1021/la502363b] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Revised: 09/11/2014] [Indexed: 05/19/2023]
Abstract
Molecular dynamics (MD) simulations of membranes are often hindered by the slow lateral diffusion of lipids and the limited time scale of MD. In order to study the dynamics of mixing and characterize the lateral distribution of lipids in converged mixtures, we report microsecond-long all-atom MD simulations performed on the special-purpose machine Anton. Two types of mixed bilayers, POPE:POPG (3:1) and POPC:cholesterol (2:1), as well as a pure POPC bilayer, were each simulated for up to 2 μs. These simulations show that POPE:POPG and POPC:cholesterol are each fully miscible at the simulated conditions, with the final states of the mixed bilayers similar to a random mixture. By simulating three POPE:POPG bilayers at different NaCl concentrations (0, 0.15, and 1 M), we also examined the effect of salt concentration on lipid mixing. While an increase in NaCl concentration is shown to affect the area per lipid, tail order, and lipid lateral diffusion, the final states of mixing remain unaltered, which is explained by the largely uniform increase in Na(+) ions around POPE and POPG. Direct measurement of water permeation reveals that the POPE:POPG bilayer with 1 M NaCl has reduced water permeability compared with those at zero or low salt concentration. Our calculations provide a benchmark to estimate the convergence time scale of all-atom MD simulations of lipid mixing. Additionally, equilibrated structures of POPE:POPG and POPC:cholesterol, which are frequently used to mimic bacterial and mammalian membranes, respectively, can be used as starting points of simulations involving these membranes.
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Affiliation(s)
- Chunkit Hong
- Department of Physics, Chinese University
of Hong Kong, Shatin, N.T., Hong Kong
| | - D. Peter Tieleman
- Department of Biological
Sciences and Center for Molecular Simulation, University of Calgary, Calgary, Alberta Canada
| | - Yi Wang
- Department of Physics, Chinese University
of Hong Kong, Shatin, N.T., Hong Kong
- E-mail: (Y.W.)
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34
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Karami L, Jalili S. Effects of cholesterol concentration on the interaction of cytarabine with lipid membranes: a molecular dynamics simulation study. J Biomol Struct Dyn 2014; 33:1254-68. [PMID: 25068451 DOI: 10.1080/07391102.2014.941936] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Liposomal cytarabine, DepoCyt, is a chemotherapy agent which is used in cancer treatment. This form of cytarabine has more efficacy and fewer side effects relative to the other forms. Since DepoCyt contains the cytarabine encapsulated within phosphatidylcholine and the sterol molecules, we modeled dioleoylphosphatidylcholine (DOPC)/cholesterol bilayer membrane as a carrier for cytarabine to study drug-bilayer interactions. For this purpose, we performed a series of united-atom molecular dynamics (MD) simulations for 25 ns to investigate the interactions between cytarabine and cholesterol-containing DOPC lipid bilayers. Only the uncharged form of cytarabine molecule was investigated. In this study, different levels of the cholesterol content (0, 20, and 40%) were used. MD simulations allowed us to determine dynamical and structural properties of the bilayer membrane and to estimate the preferred location and orientation of the cytarabine molecule inside the bilayer membrane. Properties such as membrane thickness, area per lipid, diffusion coefficient, mass density, bilayer packing, order parameters, and intermolecular interactions were examined. The results show that by increasing the cholesterol concentration in the lipid bilayers, the bilayer thickness increases and area per lipid decreases. Moreover, in accordance with the experiments, our calculations show that cholesterol molecules have ordering effect on the hydrocarbon acyl chains. Furthermore, the cytarabine molecule preferentially occupies the polar region of the lipid head groups to form specific interactions (hydrogen bonds). Our results fully support the experimental data. Our finding about drug-bilayer interaction is crucial for the liposomal drug design.
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Affiliation(s)
- Leila Karami
- a Department of Chemistry , K.N. Toosi University of Technology , P. O. Box 15875-4416, Tehran , Iran
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35
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Magarkar A, Dhawan V, Kallinteri P, Viitala T, Elmowafy M, Róg T, Bunker A. Cholesterol level affects surface charge of lipid membranes in saline solution. Sci Rep 2014; 4:5005. [PMID: 24845659 PMCID: PMC4028897 DOI: 10.1038/srep05005] [Citation(s) in RCA: 125] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 05/01/2014] [Indexed: 12/19/2022] Open
Abstract
Cholesterol is an important component of all biological membranes as well as drug delivery liposomes. We show here that increasing the level of cholesterol in a phospholipid membrane decreases surface charge in the physiological environment. Through molecular dynamics simulation we have shown that increasing the level of cholesterol decreases Na+ ion binding. Complementary experimental ζ--potential measurements have shown a decreased ζ--potential with increasing cholesterol content, indicative of reduced surface charge. Both experiments and simulations have been carried out on both saturated 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) and monounsaturated 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) membranes. This result is particularly important because membrane surface charge plays an important role in the interactions of biomembranes with peripheral membrane proteins and drug delivery liposomes with the immune system.
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Affiliation(s)
- Aniket Magarkar
- Centre for Drug Research, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
| | - Vivek Dhawan
- Bombay College of Pharmacy, University of Mumbai, Mumbai, India
| | - Paraskevi Kallinteri
- Centre for Drug Research, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
| | - Tapani Viitala
- Division of Biopharmaceutics and Pharmacokinetics, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
| | - Mohammed Elmowafy
- Division of Biopharmaceutics and Pharmacokinetics, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
| | - Tomasz Róg
- Department of Physics, Tampere University of Technology, Tampere, Finland
| | - Alex Bunker
- Centre for Drug Research, Faculty of Pharmacy, University of Helsinki, Helsinki, Finland
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36
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Olsen BN, Bielska AA, Lee T, Daily MD, Covey DF, Schlesinger PH, Baker NA, Ory DS. The structural basis of cholesterol accessibility in membranes. Biophys J 2014; 105:1838-47. [PMID: 24138860 DOI: 10.1016/j.bpj.2013.08.042] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 08/23/2013] [Accepted: 08/30/2013] [Indexed: 02/02/2023] Open
Abstract
Although the majority of free cellular cholesterol is present in the plasma membrane, cholesterol homeostasis is principally regulated through sterol-sensing proteins that reside in the cholesterol-poor endoplasmic reticulum (ER). In response to acute cholesterol loading or depletion, there is rapid equilibration between the ER and plasma membrane cholesterol pools, suggesting a biophysical model in which the availability of plasma membrane cholesterol for trafficking to internal membranes modulates ER membrane behavior. Previous studies have predominantly examined cholesterol availability in terms of binding to extramembrane acceptors, but have provided limited insight into the structural changes underlying cholesterol activation. In this study, we use both molecular dynamics simulations and experimental membrane systems to examine the behavior of cholesterol in membrane bilayers. We find that cholesterol depth within the bilayer provides a reasonable structural metric for cholesterol availability and that this is correlated with cholesterol-acceptor binding. Further, the distribution of cholesterol availability in our simulations is continuous rather than divided into distinct available and unavailable pools. This data provide support for a revised cholesterol activation model in which activation is driven not by saturation of membrane-cholesterol interactions but rather by bulk membrane remodeling that reduces membrane-cholesterol affinity.
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Affiliation(s)
- Brett N Olsen
- Diabetic Cardiovascular Disease Center, Washington University School of Medicine, St. Louis, Missouri
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37
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Molecular origins of bending rigidity in lipids with isolated and conjugated double bonds: The effect of cholesterol. Chem Phys Lipids 2014; 178:18-26. [DOI: 10.1016/j.chemphyslip.2013.12.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2013] [Revised: 12/23/2013] [Accepted: 12/24/2013] [Indexed: 01/19/2023]
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38
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Redondo-Morata L, Giannotti MI, Sanz F. Structural impact of cations on lipid bilayer models: Nanomechanical properties by AFM-force spectroscopy. Mol Membr Biol 2013; 31:17-28. [DOI: 10.3109/09687688.2013.868940] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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39
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Krause MR, Turkyilmaz S, Regen SL. Surface occupancy plays a major role in cholesterol's condensing effect. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:10303-10306. [PMID: 23902525 DOI: 10.1021/la402263w] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The condensing power of cholesterol and 5α-cholestane has been examined in liposomal membranes made from 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC). Quantitative nearest-neighbor recognition (NNR) analysis and fluorescence measurements using phase-sensitive probe Laurdan have demonstrated that 5α-cholestane exhibits a substantially weaker condensing effect. This fact, in and of itself, provides compelling evidence that cholesterol's condensing effect is critically dependent on having its steroid nucleus at the membrane surface.
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Affiliation(s)
- Martin R Krause
- Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, USA
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40
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Plesnar E, Subczynski WK, Pasenkiewicz-Gierula M. Comparative computer simulation study of cholesterol in hydrated unary and binary lipid bilayers and in an anhydrous crystal. J Phys Chem B 2013; 117:8758-69. [PMID: 23848956 DOI: 10.1021/jp402839r] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Models created with molecular dynamics simulations are used to compare the organization and dynamics of cholesterol (Chol) molecules in three different environments: (1) a hydrated pure Chol bilayer that models the Chol bilayer domain, which is a pure Chol domain embedded in the bulk membrane; (2) a 2-palmitoyl-3-oleoyl-d-glycerol-1-phosphorylcholine bilayer saturated with cholesterol (POPC-Chol50) that models the bulk membrane; (3) a Chol crystal. The computer model of the hydrated pure Chol bilayer is stable on the microsecond time scale. Some structural characteristics of Chol molecules in the Chol bilayer are similar to those in the POPC-Chol50 bilayer (e.g., tilt of Chol rings and chains), while others are similar to those in Chol crystals (e.g., surface area per Chol, bilayer thickness). The key result of this study is that the Chol bilayer has, unexpectedly, a dynamic structure, with Chol mobility similar to that in the POPC-Chol50 bilayer though slower. This is the major difference compared to Chol crystals, where Chol molecules are immobile. Also, water accessibility to Chol-OH groups in the Chol bilayer is not limited. On average, each Chol molecule makes 2.3 hydrogen bonds with water in the Chol bilayer, compared with 1.7 hydrogen bonds in the POPC-Col50 bilayer.
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Affiliation(s)
- Elzbieta Plesnar
- Department of Computational Biophysics and Bioinformatics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
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41
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Kett PJN, Casford MTL, Davies PB. Orientation of cholesterol in hybrid bilayer membranes calculated from the phases of methyl resonances in sum frequency generation spectra. J Chem Phys 2013; 138:225101. [DOI: 10.1063/1.4807854] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Affiliation(s)
- P J N Kett
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, United Kingdom
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42
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Hughes ZE, Malajczuk CJ, Mancera RL. The Effects of Cryosolvents on DOPC−β-Sitosterol Bilayers Determined from Molecular Dynamics Simulations. J Phys Chem B 2013; 117:3362-75. [DOI: 10.1021/jp400975y] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Zak E. Hughes
- Western Australian Biomedical
Research Institute, Curtin
Health Innovation Research Institute, School of Biomedical Sciences, Curtin University, P.O. Box U1987, Perth WA, 6845,
Australia
| | - Chris J. Malajczuk
- Western Australian Biomedical
Research Institute, Curtin
Health Innovation Research Institute, School of Biomedical Sciences, Curtin University, P.O. Box U1987, Perth WA, 6845,
Australia
| | - Ricardo L. Mancera
- Western Australian Biomedical
Research Institute, Curtin
Health Innovation Research Institute, School of Biomedical Sciences, Curtin University, P.O. Box U1987, Perth WA, 6845,
Australia
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43
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Khelashvili G, Harries D. How Cholesterol Tilt Modulates the Mechanical Properties of Saturated and Unsaturated Lipid Membranes. J Phys Chem B 2013; 117:2411-21. [DOI: 10.1021/jp3122006] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- George Khelashvili
- Department of Physiology and Biophysics, Weill Cornell Medical College, New York,
New York 10065, United States
| | - Daniel Harries
- Institute of Chemistry and the Fritz Haber Research Center, The Hebrew University of Jerusalem,
Jerusalem 91904, Israel
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44
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Effects of DPPC/Cholesterol liposomes on the properties of freshly precipitated calcium carbonate. Colloids Surf B Biointerfaces 2013; 101:44-8. [DOI: 10.1016/j.colsurfb.2012.06.013] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2012] [Revised: 06/14/2012] [Accepted: 06/16/2012] [Indexed: 11/18/2022]
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45
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Morishima F, Inokuchi Y, Ebata T. Laser Spectroscopic Study of β-Estradiol and Its Monohydrated Clusters in a Supersonic Jet. J Phys Chem A 2012; 116:8201-8. [DOI: 10.1021/jp302209z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Fumiya Morishima
- Department of Chemistry, Graduate
School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
| | - Yoshiya Inokuchi
- Department of Chemistry, Graduate
School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
| | - Takayuki Ebata
- Department of Chemistry, Graduate
School of Science, Hiroshima University, Higashi-Hiroshima 739-8526, Japan
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46
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Bauer BA, Patel S. Recent applications and developments of charge equilibration force fields for modeling dynamical charges in classical molecular dynamics simulations. Theor Chem Acc 2012. [DOI: 10.1007/s00214-012-1153-7] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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47
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Lucas TR, Bauer BA, Patel S. Charge equilibration force fields for molecular dynamics simulations of lipids, bilayers, and integral membrane protein systems. BIOCHIMICA ET BIOPHYSICA ACTA 2012; 1818:318-29. [PMID: 21967961 PMCID: PMC4216680 DOI: 10.1016/j.bbamem.2011.09.016] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2011] [Revised: 09/13/2011] [Accepted: 09/14/2011] [Indexed: 01/06/2023]
Abstract
With the continuing advances in computational hardware and novel force fields constructed using quantum mechanics, the outlook for non-additive force fields is promising. Our work in the past several years has demonstrated the utility of polarizable force fields, those based on the charge equilibration formalism, for a broad range of physical and biophysical systems. We have constructed and applied polarizable force fields for lipids and lipid bilayers. In this review of our recent work, we discuss the formalism we have adopted for implementing the charge equilibration (CHEQ) method for lipid molecules. We discuss the methodology, related issues, and briefly discuss results from recent applications of such force fields. Application areas include DPPC-water monolayers, potassium ion permeation free energetics in the gramicidin A bacterial channel, and free energetics of permeation of charged amino acid analogs across the water-bilayer interface. This article is part of a Special Issue entitled: Membrane protein structure and function.
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Affiliation(s)
- Timothy R. Lucas
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA
| | - Brad A. Bauer
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA
| | - Sandeep Patel
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA
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48
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Lucas TR, Bauer BA, Davis JE, Patel S. Molecular dynamics simulation of hydrated DPPC monolayers using charge equilibration force fields. J Comput Chem 2012; 33:141-52. [PMID: 21997857 PMCID: PMC3488352 DOI: 10.1002/jcc.21927] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2011] [Revised: 06/24/2011] [Accepted: 07/30/2011] [Indexed: 12/21/2022]
Abstract
We present results of molecular dynamics simulations of a model DPPC-water monolayer using charge equilibration (CHEQ) force fields, which explicitly account for electronic polarization in a classical treatment of intermolecular interactions. The surface pressure, determined as the difference between the monolayer and pure water surface tensions at 323 K, is predicted to be 22.92 ±1.29 dyne/cm, just slightly below the broad range of experimental values reported for this system. The surface tension for the DPPC-water monolayer is predicted to be 42.35 ±1.16 dyne/cm, in close agreement with the experimentally determined value of 40.9 dyne/cm. This surface tension is also consistent with the value obtained from DPPC monolayer simulations using state-of-the-art nonpolarizable force fields. The current results of simulations predict a monolayer-water potential difference relative to the pure water-air interface of 0.64 ±0.02 Volts, an improved prediction compared to the fixed-charge CHARMM27 force field, yet still overestimating the experimental range of 0.3 to 0.45 Volts. As the charge equilibration model is a purely charge-based model for polarization, the current results suggest that explicitly modeled polarization effects can offer improvements in describing interfacial electrostatics in such systems.
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Affiliation(s)
- Timothy R. Lucas
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA
| | - Brad A. Bauer
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA
| | - Joseph E. Davis
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA
| | - Sandeep Patel
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, USA
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49
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Takeuchi H, Sata M. The relationship among brain natriuretic peptide (BNP), cholesterol and lipoprotein. HEART ASIA 2012; 4:11-5. [PMID: 27326018 PMCID: PMC4898600 DOI: 10.1136/heartasia-2011-010042] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/19/2012] [Indexed: 12/14/2022]
Abstract
OBJECTIVE To study the relationship among brain natriuretic peptide (BNP), cholesterol and lipoprotein. DESIGN A retrospective, cross-sectional study. SETTING Tokushima University Hospital area. PATIENTS A retrospective study of 46 patients (nine inpatients and 37 outpatients) with angina pectoris or arrhythmias who were seen at Tokushima University Hospital Cardiovascular Division and had measurements of their BNP, fatty acid and lipid profile. The average age of patients was 57±17 years, and 39% were male subjects. MAIN OUTCOME MEASURES BNP, dihomo-γ-linolenic acid, arachidonic acid, eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), apolipoproteinA1, apolipoprotein A2 (ApoA2), apolipoprotein B (ApoB), apolipoprotein C2, apolipoprotein C3, apolipoprotein E, total cholesterol (TC), triglyceride, high density lipoprotein cholesterol and low density lipoprotein cholesterol. RESULTS The baseline characteristics of the patients were shown in table 1 and the data of lipoprotein were shown in table 2. Table 3 shows the relationship among BNP, cholesterol and lipoprotein. The authors found significant negative correlation between serum levels of BNP and ApoA2 (figure 1; r=-0.458, p=0.001), serum levels of BNP and ApoB (figure 2; r=-0.328, p=0.026) and serum levels of BNP and TC (figure 3; r=-0.383, p=0.010). There is a possibility that dietary EPA and DHA may modulate cardiac mitochondrial and autonomic nervous system dysfunction via fatty-acids-PPARs-PTEN-PI3K/Akt-SREBPs system and affect serum BNP levels indirectly. CONCLUSION BNP had significant negative correlation with ApoA2, ApoB and TC. The findings suggest that increasing serum levels of ApoA2, ApoB and TC may have an effect on improving heart function. But the mechanism is presently unclear.
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Affiliation(s)
- Hidekazu Takeuchi
- Department of Cardiovascular Medicine, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan
| | - Masataka Sata
- Department of Cardiovascular Medicine, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan
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50
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Khelashvili G, Rappolt M, Chiu SW, Pabst G, Harries D. Impact of sterol tilt on membrane bending rigidity in cholesterol and 7DHC-containing DMPC membranes. SOFT MATTER 2011; 7:10299-10312. [PMID: 23173009 PMCID: PMC3500765 DOI: 10.1039/c1sm05937h] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Cholesterol is so essential to the proper function of mammalian cell membranes that even strikingly small inborn errors in cholesterol synthesis can be devastating. Here we combine molecular dynamics simulations with small angle x-ray diffraction experiments to compare mixed sterol/DMPC membranes over a wide range of sterol compositions for two types of sterols: cholesterol and its immediate metabolic precursor 7DHC, that differs from cholesterol by one double bond. We find that while most membrane properties are only slightly affected by the replacement of one sterol by the other, the tilt degree of freedom, as gauged by the tilt modulus, is significantly larger for cholesterol than for 7DHC over a large range of concentrations. In silico mutations of one sterol into the other further support these findings. Moreover, bending rigidities calculated from simulations and estimated in experiments show that cholesterol stiffens membranes to a larger extent than 7DHC. We discuss the possible mechanistic link between sterol tilt and the way it impacts the membrane mechanical properties, and comment on how this link may shed light on the way replacement of cholesterol by 7DHC leads to disease.
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Affiliation(s)
| | - Michael Rappolt
- Institute of Biophysics and Nanosystems Research, Austrian Academy of Sciences, A-8042 Graz, Austria
| | - See-Wing Chiu
- Institute of Advanced Science and Technology, University of Illinois, Urbana, IL 61801, United States
| | - Georg Pabst
- Institute of Biophysics and Nanosystems Research, Austrian Academy of Sciences, A-8042 Graz, Austria
| | - Daniel Harries
- Institute of Chemistry and the Fritz Haber Research Center, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
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