1
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Okayama A, Hoshino T, Wada K, Takahashi H. Comparison of structural effects of cholesterol, lanosterol, and oxysterol on phospholipid (POPC) bilayers. Chem Phys Lipids 2024; 259:105376. [PMID: 38325710 DOI: 10.1016/j.chemphyslip.2024.105376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Revised: 12/26/2023] [Accepted: 01/31/2024] [Indexed: 02/09/2024]
Abstract
Membrane sterols contribute to the function of biomembranes by regulating the physical properties of the lipid bilayers. Cholesterol, a typical mammalian sterol, is biosynthesized by oxidation of lanosterol. From a molecular evolutionary perspective, lanosterol is considered the ancestral molecule of cholesterol. Here, we studied whether cholesterol is superior to lanosterol in regulating the physical properties of the lipid bilayer in terms of the structural effect on model biomembranes composed of a phospholipid. For comparison, oxysterol, which is formed by oxidation of cholesterol, was also studied. The phospholipid used was 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), which is abundantly found in mammalian biomembranes, and 7β-hydroxycholesterol, which is highly cytotoxic, was used as the oxysterol. The apparent molecular volume was calculated from the mass density determined by the flotation method using H2O and D2O, and the bilayer thickness was determined by reconstructing the electron density distribution from X-ray diffraction data of the POPC/sterol mixtures at a sterol concentration of 30 mol%. The apparent occupied area at the bilayer surface was calculated from the above two structural data. The cholesterol system had the thickest bilayer thickness and the smallest occupied area of the three sterols studied here. This indicates that the POPC/cholesterol bilayer has a better barrier property than the other two systems. Compared to cholesterol, the effects of lanosterol and 7β-hydroxycholesterol on lipid bilayer properties can be interpreted as suboptimal for the function of mammalian biomembranes.
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Affiliation(s)
- Ayumi Okayama
- Division of Pure and Applied Science, Faculty of Science and Technology, Gunma University, 4-2 Aramaki, Maebashi, Gunma 371-8510, Japan
| | - Tatsuya Hoshino
- Division of Pure and Applied Science, Faculty of Science and Technology, Gunma University, 4-2 Aramaki, Maebashi, Gunma 371-8510, Japan
| | - Kohei Wada
- Division of Pure and Applied Science, Faculty of Science and Technology, Gunma University, 4-2 Aramaki, Maebashi, Gunma 371-8510, Japan
| | - Hiroshi Takahashi
- Division of Pure and Applied Science, Faculty of Science and Technology, Gunma University, 4-2 Aramaki, Maebashi, Gunma 371-8510, Japan.
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2
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Zimmerberg J, Soubias O, Pastor RW. Special issue for Klaus Gawrisch. Biophys J 2023; 122:E1-E8. [PMID: 36921597 PMCID: PMC10111273 DOI: 10.1016/j.bpj.2023.02.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 02/15/2023] [Accepted: 02/15/2023] [Indexed: 03/17/2023] Open
Affiliation(s)
- Joshua Zimmerberg
- Section on Integrative Biophysics, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Olivier Soubias
- Macromolecular NMR Section, Center for Structural Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD, USA
| | - Richard W Pastor
- Laboratory of Computational Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
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3
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DiPasquale M, Nguyen MHL, Pabst G, Marquardt D. Partial Volumes of Phosphatidylcholines and Vitamin E: α-Tocopherol Prefers Disordered Membranes. J Phys Chem B 2022; 126:6691-6699. [PMID: 36027485 DOI: 10.1021/acs.jpcb.2c04209] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Despite its discovery over 95 years ago, the biological and nutritional roles of vitamin E remain subjects of much controversy. Though it is known to possess antioxidant properties, recent assertions have implied that vitamin E may not be limited to this function in living systems. Through densitometry measurements and small-angle X-ray scattering we observe favorable interactions between α-tocopherol and unsaturated phospholipids, with more favorable interactions correlating to an increase in lipid chain unsaturation. Our data provide evidence that vitamin E may preferentially associate with oxygen sensitive lipids─an association that is considered innate for a viable membrane antioxidant.
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Affiliation(s)
- Mitchell DiPasquale
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario N9B 3P4, Canada
| | - Michael H L Nguyen
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario N9B 3P4, Canada
| | - Georg Pabst
- Institute of Molecular Biosciences, Biophysics Division, NAWI Graz, University of Graz, Graz 8010, Austria.,BioTechMed-Graz, Graz 8010, Austria
| | - Drew Marquardt
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario N9B 3P4, Canada.,Department of Physics, University of Windsor, Windsor, Ontario N9B 3P4, Canada
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4
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Kurakin S, Ivankov O, Skoi V, Kuklin A, Uhríková D, Kučerka N. Cations Do Not Alter the Membrane Structure of POPC—A Lipid With an Intermediate Area. Front Mol Biosci 2022; 9:926591. [PMID: 35898308 PMCID: PMC9312375 DOI: 10.3389/fmolb.2022.926591] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 06/07/2022] [Indexed: 12/02/2022] Open
Abstract
Combining small-angle neutron scattering (SANS), small-angle X-ray scattering (SAXS), and densitometric measurements, we have studied the interactions of the divalent cations Ca2+ and Mg2+ with the lipid vesicles prepared of a mixed-chain palmitoyl-oleoyl-phosphatidylcholine (POPC) at 25°C. The structural parameters of the POPC bilayer, such as the bilayer thickness, lateral area, and volume per lipid, displayed no changes upon the ion addition at concentrations up to 30 mM and minor changes at > 30 mM Ca2+ and Mg2+, while some decrease in the vesicle radius was observed over the entire concentration range studied. This examination allows us to validate the concept of lipid–ion interactions governed by the area per lipid suggested previously and to propose the mixed mode of those interactions that emerge in the POPC vesicles. We speculate that the average area per POPC lipid that corresponds to the cutoff length of lipid–ion interactions generates an equal but opposite impact on ion bridges and separate lipid–ion pairs. As a result of the dynamic equilibrium, the overall structural properties of bilayers are not affected. As the molecular mechanism proposed is affected by the structural properties of a particular lipid, it might help us to understand the fundamentals of processes occurring in complex multicomponent membrane systems.
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Affiliation(s)
- Sergei Kurakin
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, Russia
- Institute of Physics, Kazan Federal University, Kazan, Russia
| | - Oleksandr Ivankov
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, Russia
| | - Vadim Skoi
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, Russia
- Moscow Institute of Physics and Technology, Dolgoprudnyi, Russia
| | - Alexander Kuklin
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, Russia
- Moscow Institute of Physics and Technology, Dolgoprudnyi, Russia
| | - Daniela Uhríková
- Department of Physical Chemistry of Drugs, Faculty of Pharmacy, Comenius University Bratislava, Bratislava, Slovakia
| | - Norbert Kučerka
- Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, Russia
- Department of Physical Chemistry of Drugs, Faculty of Pharmacy, Comenius University Bratislava, Bratislava, Slovakia
- *Correspondence: Norbert Kučerka,
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5
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Rasmussen HØ, Otzen DE, Pedersen JS. Induction, inhibition, and incorporation: Different roles for anionic and zwitterionic lysolipids in the fibrillation of the functional amyloid FapC. J Biol Chem 2022; 298:101569. [PMID: 35007533 PMCID: PMC8888460 DOI: 10.1016/j.jbc.2022.101569] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 12/29/2021] [Accepted: 12/30/2021] [Indexed: 11/16/2022] Open
Abstract
Amyloid proteins are widespread in nature both as pathological species involved in several diseases and as functional entities that can provide protection and storage for the organism. Lipids have been found in amyloid deposits from various amyloid diseases and have been shown to strongly affect the formation and structure of both pathological and functional amyloid proteins. Here, we investigate how fibrillation of the functional amyloid FapC from Pseudomonas is affected by two lysolipids, the zwitterionic lipid 1-myristoyl-2-hydroxy-sn-glycero-3-phosphocholine and the anionic lipid 1-myristoyl-2-hydroxy-sn-glycero-3-phospho-(1′-rac-glycerol) (LPG). Small-angle X-ray scattering, circular dichroism, dynamic light scattering, and thioflavin T fluorescence measurements were performed simultaneously on the same sample to ensure reproducibility and allow a multimethod integrated analysis. We found that LPG strongly induces fibrillation around its critical micelle concentration (cmc) by promoting formation of large structures, which mature via accumulation of intermediate fibril structures with a large cross section. At concentrations above its cmc, LPG strongly inhibits fibrillation by locking FapC in a core–shell complex. In contrast, lipid 1-myristoyl-2-hydroxy-sn-glycero-3-phosphocholine induces fibrillation at concentrations above its cmc, not via strong interactions with FapC but by being incorporated during fibrillation and likely stabilizing the fibrillation nucleus to reduce the lag phase. Finally, we show that LPG is not incorporated into the fibril during assembly but rather can coat the final fibril. We conclude that lipids affect both the mechanism and outcome of fibrillation of functional amyloid, highlighting a role for lipid concentration and composition in the onset and mechanism of fibrillation in vivo.
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Affiliation(s)
- Helena Østergaard Rasmussen
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus C, Denmark; Department of Chemistry, Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus C, Denmark
| | - Daniel E Otzen
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus C, Denmark; Department of Molecular Biology and Genetics, Gustav Wieds Vej 14, Aarhus University, 8000 Aarhus C, Denmark.
| | - Jan Skov Pedersen
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus C, Denmark; Department of Chemistry, Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus C, Denmark.
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6
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Salata GC, Malagó ID, Carvalho Dartora VFM, Marçal Pessoa AF, Fantini MCDA, Costa SKP, Machado-Neto JA, Lopes LB. Microemulsion for Prolonged Release of Fenretinide in the Mammary Tissue and Prevention of Breast Cancer Development. Mol Pharm 2021; 18:3401-3417. [PMID: 34482696 DOI: 10.1021/acs.molpharmaceut.1c00319] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The need of pharmacological strategies to preclude breast cancer development motivated us to develop a non-aqueous microemulsion (ME) capable of forming a depot after administration in the mammary tissue and uptake of interstitial fluids for prolonged release of the retinoid fenretinide. The selected ME was composed of phosphatidylcholine/tricaprylin/propylene glycol (45:5:50, w/w/w) and presented a droplet diameter of 175.3 ± 8.9 nm. Upon water uptake, the ME transformed successively into a lamellar phase, gel, and a lamellar phase-containing emulsion in vitro as the water content increased and released 30% of fenretinide in vitro after 9 days. Consistent with the slow release, the ME formed a depot in cell cultures and increased fenretinide IC50 values by 68.3- and 13.2-fold in MCF-7 and T-47D cells compared to a solution, respectively. At non-cytotoxic concentrations, the ME reduced T-47D cell migration by 75.9% and spheroid growth, resulting in ∼30% smaller structures. The depot formed in vivo prolonged a fluorochrome release for 30 days without producing any sings of local irritation. In a preclinical model of chemically induced carcinogenesis, ME administration every 3 weeks for 3 months significantly reduced (4.7-fold) the incidence of breast tumors and increased type II collagen expression, which might contribute to limit spreading. These promising results support the potential ME applicability as a preventive therapy of breast cancer.
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Affiliation(s)
- Giovanna Cassone Salata
- Departamento de Farmacologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av. Prof. Lineu Prestes, 1524, São Paulo, São Paulo 05508-000, Brazil
| | - Isabella D Malagó
- Departamento de Farmacologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av. Prof. Lineu Prestes, 1524, São Paulo, São Paulo 05508-000, Brazil
| | - Vanessa F M Carvalho Dartora
- Departamento de Farmacologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av. Prof. Lineu Prestes, 1524, São Paulo, São Paulo 05508-000, Brazil
| | - Ana Flávia Marçal Pessoa
- Departamento de Cirurgia, LIM26, Faculdade de Medicina, Universidade de São Paulo, Av. Dr. Arnaldo, 455, São Paulo, São Paulo 01246903, Brazil
| | - Márcia Carvalho de Abreu Fantini
- Departamento de Física Aplicada, Instituto de Física, Universidade de São Paulo, Rua do Matão, 1371, São Paulo, São Paulo 05508-090, Brazil
| | - Soraia K P Costa
- Departamento de Farmacologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av. Prof. Lineu Prestes, 1524, São Paulo, São Paulo 05508-000, Brazil
| | - João Agostinho Machado-Neto
- Departamento de Farmacologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av. Prof. Lineu Prestes, 1524, São Paulo, São Paulo 05508-000, Brazil
| | - Luciana B Lopes
- Departamento de Farmacologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, Av. Prof. Lineu Prestes, 1524, São Paulo, São Paulo 05508-000, Brazil
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7
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Häffner SM, Parra-Ortiz E, Browning KL, Jørgensen E, Skoda MWA, Montis C, Li X, Berti D, Zhao D, Malmsten M. Membrane Interactions of Virus-like Mesoporous Silica Nanoparticles. ACS NANO 2021; 15:6787-6800. [PMID: 33724786 DOI: 10.1021/acsnano.0c10378] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
In the present study, we investigated lipid membrane interactions of silica nanoparticles as carriers for the antimicrobial peptide LL-37 (LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES). In doing so, smooth mesoporous nanoparticles were compared to virus-like mesoporous nanoparticles, characterized by a "spiky" external surface, as well as to nonporous silica nanoparticles. For this, we employed a combination of neutron reflectometry, ellipsometry, dynamic light scattering, and ζ-potential measurements for studies of bacteria-mimicking bilayers formed by palmitoyloleoylphosphatidylcholine/palmitoyloleoylphosphatidylglycerol. The results show that nanoparticle topography strongly influences membrane binding and destabilization. We found that virus-like particles are able to destabilize such lipid membranes, whereas the corresponding smooth silica nanoparticles are not. This effect of particle spikes becomes further accentuated after loading of such particles with LL-37. Thus, peptide-loaded virus-like nanoparticles displayed more pronounced membrane disruption than either peptide-loaded smooth nanoparticles or free LL-37. The structural basis of this was clarified by neutron reflectometry, demonstrating that the virus-like nanoparticles induce trans-membrane defects and promote incorporation of LL-37 throughout both bilayer leaflets. The relevance of such effects of particle spikes for bacterial membrane rupture was further demonstrated by confocal microscopy and live/dead assays on Escherichia coli bacteria. Taken together, these findings demonstrate that topography influences the interaction of nanoparticles with bacteria-mimicking lipid bilayers, both in the absence and presence of antimicrobial peptides, as well as with bacteria. The results also identify virus-like mesoporous nanoparticles as being of interest in the design of nanoparticles as delivery systems for antimicrobial peptides.
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Affiliation(s)
| | - Elisa Parra-Ortiz
- Department of Pharmacy, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - Kathryn L Browning
- Department of Pharmacy, University of Copenhagen, DK-2100 Copenhagen, Denmark
| | - Elin Jørgensen
- Costerton Biofilm Center, Department of Immunology and Microbiology, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Maximilian W A Skoda
- ISIS Pulsed Neutron and Muon Source, Rutherford Appleton Laboratory, Harwell, Oxfordshire OX11 0QX, United Kingdom
| | - Costanza Montis
- CSGI and Department of Chemistry "Ugo Schiff″, University of Florence, IT-50019 Sesto Fiorentino, Italy
| | - Xiaomin Li
- Department of Chemistry, Collaborative Innovation Center of Chemistry for Energy Materials, State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai 200433, People's Republic of China
| | - Debora Berti
- CSGI and Department of Chemistry "Ugo Schiff″, University of Florence, IT-50019 Sesto Fiorentino, Italy
| | - Dongyuan Zhao
- Department of Chemistry, Collaborative Innovation Center of Chemistry for Energy Materials, State Key Laboratory of Molecular Engineering of Polymers, Fudan University, Shanghai 200433, People's Republic of China
| | - Martin Malmsten
- Department of Pharmacy, University of Copenhagen, DK-2100 Copenhagen, Denmark
- Department of Physical Chemistry 1, University of Lund, SE-22100 Lund, Sweden
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8
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Kelley EG, Butler PD, Ashkar R, Bradbury R, Nagao M. Scaling relationships for the elastic moduli and viscosity of mixed lipid membranes. Proc Natl Acad Sci U S A 2020; 117:23365-23373. [PMID: 32883879 PMCID: PMC7519290 DOI: 10.1073/pnas.2008789117] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The elastic and viscous properties of biological membranes play a vital role in controlling cell functions that require local reorganization of the membrane components as well as dramatic shape changes such as endocytosis, vesicular trafficking, and cell division. These properties are widely acknowledged to depend on the unique composition of lipids within the membrane, yet the effects of lipid mixing on the membrane biophysical properties remain poorly understood. Here, we present a comprehensive characterization of the structural, elastic, and viscous properties of fluid membranes composed of binary mixtures of lipids with different tail lengths. We show that the mixed lipid membrane properties are not simply additive quantities of the single-component analogs. Instead, the mixed membranes are more dynamic than either of their constituents, quantified as a decrease in their bending modulus, area compressibility modulus, and viscosity. While the enhanced dynamics are seemingly unexpected, we show that the measured moduli and viscosity for both the mixed and single-component bilayers all scale with the area per lipid and collapse onto respective master curves. This scaling links the increase in dynamics to mixing-induced changes in the lipid packing and membrane structure. More importantly, the results show that the membrane properties can be manipulated through lipid composition the same way bimodal blends of surfactants, liquid crystals, and polymers are used to engineer the mechanical properties of soft materials, with broad implications for understanding how lipid diversity relates to biomembrane function.
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Affiliation(s)
- Elizabeth G Kelley
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899;
| | - Paul D Butler
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, DE 19716
- Department of Chemistry, The University of Tennessee, Knoxville, TN 37996
| | - Rana Ashkar
- Physics Department, Virginia Tech, Blacksburg, VA 20461
- Center for Soft Matter and Biological Physics, Virginia Tech, Blacksburg, VA 20461
| | - Robert Bradbury
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899
- Center for Exploration of Energy and Matter, Indiana University, Bloomington, IN 47408
| | - Michihiro Nagao
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899
- Center for Exploration of Energy and Matter, Indiana University, Bloomington, IN 47408
- Department of Physics and Astronomy, University of Delaware, Newark, DE 19716
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9
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Martinez-Calle M, Prieto M, Olmeda B, Fedorov A, Loura LM, Pérez-Gil J. Pulmonary surfactant protein SP-B nanorings induce the multilamellar organization of surfactant complexes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183216. [DOI: 10.1016/j.bbamem.2020.183216] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 01/17/2020] [Accepted: 02/02/2020] [Indexed: 11/25/2022]
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10
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Shtangel O, Mezer AA. A phantom system for assessing the effects of membrane lipids on water proton relaxation. NMR IN BIOMEDICINE 2020; 33:e4209. [PMID: 31899589 DOI: 10.1002/nbm.4209] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 09/24/2019] [Accepted: 10/13/2019] [Indexed: 06/10/2023]
Abstract
Quantitative MRI (qMRI) is a method for the non-invasive study of brain-structure-associated changes expressed with measurable units. The qMRI-derived parameters have been shown to reflect brain tissue composition such as myelin content. Nevertheless, it remains a major challenge to identify and quantify the contributions of specific molecular components to the MRI signal. Here, we describe a phantom system that can be used to evaluate the contribution of membrane lipids to qMRI-derived parameters. We used a hydration-dehydration dry film technique to formulate liposomes that can be used as a model of the bilayer lipid membrane. The liposomes were comprised of the most abundant types of lipid found in the human brain. We then applied clinically available qMRI techniques with adjusted bias corrections in order to test the ability of the phantom system to estimate multiple qMRI parameters such as proton density (PD), T1 , T2 , T2 * and magnetization transfer. In addition, we accurately measured the phantom sample water fraction (normalized PD). A similar protocol was also applied to the human brain in vivo. The phantom system allows for a reliable estimation of qMRI parameters for phantoms composed of various lipid types using a clinical MRI scanner. We also found a comparable reproducibility between the phantom and in vivo human brain qMRI estimations. To conclude, we have successfully created a biologically relevant liposome phantom system whose lipid composition can be fully controlled. Our lipid system and analysis can be used to measure the contributions to qMRI parameters of membrane lipids found in the human brain under scanning conditions that are relevant to in vivo human brain scans. Such a model system can be used to test the contributions of lipidomic changes in normal and pathological brain states.
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Affiliation(s)
- Oshrat Shtangel
- Edmond and Lily Safra Center for Brain Sciences, Hebrew University of Jerusalem, Israel
| | - Aviv A Mezer
- Edmond and Lily Safra Center for Brain Sciences, Hebrew University of Jerusalem, Israel
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11
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Abstract
The combination of supramolecular functional systems with biomolecular chemistry has been a fruitful exercise for decades, leading to a greater understanding of biomolecules and to a great variety of applications, for example, in drug delivery and sensing. Within these developments, the phospholipid bilayer membrane, surrounding live cells, with all its functions has also intrigued supramolecular chemists. Herein, recent efforts from the supramolecular chemistry community to mimic natural functions of lipid membranes, such as sensing, molecular recognition, membrane fusion, signal transduction, and gated transport, are reviewed.
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Affiliation(s)
- Andrea Barba‐Bon
- Department of Life Sciences and ChemistryJacobs University BremenCampus Ring 128759BremenGermany
| | - Mohamed Nilam
- Department of Life Sciences and ChemistryJacobs University BremenCampus Ring 128759BremenGermany
| | - Andreas Hennig
- Department of Life Sciences and ChemistryJacobs University BremenCampus Ring 128759BremenGermany
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12
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Al-Dulaymi M, Mohammed-Saeid W, El-Aneed A, Badea I. Peptide-Modified Gemini Surfactants: Preparation and Characterization for Gene Delivery. Methods Mol Biol 2020; 2000:203-225. [PMID: 31148017 DOI: 10.1007/978-1-4939-9516-5_14] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Diquaternary ammonium-based gemini surfactants have been investigated widely as nonviral gene delivery systems. These unique cationic lipids have versatility in their chemical structure, show relatively low toxicity, are able to compact genetic material (pDNA, RNA) into nano-sized lipoplexes, and can be easily produced. In addition, the gemini surfactants show significant improvement in the transfection activity and biocompatibility compared to other cationic lipids used as nonviral gene delivery agents. The successful applications of gemini surfactant-based lipoplexes as topical gene delivery systems in animal models indicate their potential as noninvasive carriers for genetic immunization, theranostic agents, and in other gene therapy treatments. Detailed physicochemical characterization of gemini surfactant lipoplexes is a key factor in terms of formulation optimization and elucidation of the cellular uptake and stability of the lipoplexes system. In this chapter, we describe in detail different formulation methods to prepare gemini surfactant lipoplexes and comprehensive physicochemical characterization. In addition, we illustrate general protocols for in vitro evaluations.
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Affiliation(s)
- Mays Al-Dulaymi
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK, Canada
| | - Waleed Mohammed-Saeid
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK, Canada.,College of Pharmacy, Taibah University, Madina, Saudi Arabia
| | - Anas El-Aneed
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK, Canada
| | - Ildiko Badea
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK, Canada.
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13
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A comparative study of the effects of 7β-hydroxycholesterol, 25-hydroxycholesterol, and cholesterol on the structural and thermal phase behavior of multilamellar dipalmitoylphosphatidylcholine bilayer vesicles. Chem Phys Lipids 2020; 227:104872. [DOI: 10.1016/j.chemphyslip.2020.104872] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Revised: 12/23/2019] [Accepted: 01/03/2020] [Indexed: 01/11/2023]
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14
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Perez Enriquez DJ, Dell’ Arciprete ML, Dittler ML, Miñan A, Prieto E, Gonzalez MC. Amorphous calcium organophosphate nanoshells as potential carriers for drug delivery to Ca2+-enriched surfaces. NEW J CHEM 2020. [DOI: 10.1039/c9nj06414a] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Our amorphous calcium organophosphate nanoshells are prone to agglomerate and disassemble when Ca2+ ions are present in the solution and on surfaces. This have great implications for targeting and drug release in Ca-rich environments, such as bone.
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Affiliation(s)
- Darlin J. Perez Enriquez
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)
- CCT-La Plata-CONICET
- Universidad Nacional de La Plata
- La Plata
- Argentina
| | - María L. Dell’ Arciprete
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)
- CCT-La Plata-CONICET
- Universidad Nacional de La Plata
- La Plata
- Argentina
| | - María L. Dittler
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)
- CCT-La Plata-CONICET
- Universidad Nacional de La Plata
- La Plata
- Argentina
| | - Alejandro Miñan
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)
- CCT-La Plata-CONICET
- Universidad Nacional de La Plata
- La Plata
- Argentina
| | - Eduardo Prieto
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)
- CCT-La Plata-CONICET
- Universidad Nacional de La Plata
- La Plata
- Argentina
| | - Mónica C. Gonzalez
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas (INIFTA)
- CCT-La Plata-CONICET
- Universidad Nacional de La Plata
- La Plata
- Argentina
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15
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Seper BC, Ko A, Abma AF, Folkerts AD, Tristram-Nagle S, Harper PE. Methylene volumes in monoglyceride bilayers are larger than in liquid alkanes. Chem Phys Lipids 2019; 226:104833. [PMID: 31738879 DOI: 10.1016/j.chemphyslip.2019.104833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 09/26/2019] [Accepted: 10/09/2019] [Indexed: 11/26/2022]
Abstract
The densities as a function of temperature of four fully hydrated saturated monoglycerides with even chain lengths ranging from eight to fourteen were determined by vibrating tube densitometry and their phase transition temperatures were determined by differential scanning calorimetry (DSC). We find the volume of a methylene group in a monoglyceride bilayer is 2% larger than in liquid alkanes at physiological temperatures, similar to the methylene group volumes found in phosphatidylcholine (PC) bilayers. Additionally, we carefully consider the traditional method of calculating component volumes from experimental data and note potential difficulties in this approach. In the literature, the ratio of terminal methyl volume (CH3) to methylene (CH2) volumes is typically assumed to be 2. By analysis of literature alkane data, we find this ratio actually ranges from 1.9 to 2.3 for temperatures ranging from 0 °C to 100 °C. For a rough sense of scale, we note that to effect a 2% reduction in volume requires of order 200 atmospheres of pressure, and pressures of this magnitude are biologically relevant. For instance, this amount of pressure is sufficient to reverse the effect of anesthesia. The component volumes obtained are an important parameter used for determining the structure of lipid bilayers and for molecular dynamics simulations.
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Affiliation(s)
- Brian C Seper
- Department of Physics and Astronomy, Calvin University, Grand Rapids, MI 49546, USA
| | - Anthony Ko
- Biological Physics Group, Physics Department, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213, USA
| | - Aaron F Abma
- Department of Physics and Astronomy, Calvin University, Grand Rapids, MI 49546, USA
| | - Andrew D Folkerts
- Department of Physics and Astronomy, Calvin University, Grand Rapids, MI 49546, USA
| | - Stephanie Tristram-Nagle
- Biological Physics Group, Physics Department, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213, USA
| | - Paul E Harper
- Department of Physics and Astronomy, Calvin University, Grand Rapids, MI 49546, USA.
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16
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Becker R, Bouwens T, Schippers ECF, van Gelderen T, Hilbers M, Woutersen S, Reek JNH. Photocatalytic Hydrogen Generation by Vesicle-Embedded [FeFe]Hydrogenase Mimics: A Mechanistic Study. Chemistry 2019; 25:13921-13929. [PMID: 31418952 PMCID: PMC6899470 DOI: 10.1002/chem.201902514] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2019] [Indexed: 12/22/2022]
Abstract
Artificial photosynthesis—the direct photochemical generation of hydrogen from water—is a promising but scientifically challenging future technology. Because nature employs membranes for photodriven reactions, the aim of this work is to elucidate the effect of membranes on artificial photocatalysis. To do so, a combination of electrochemistry, photocatalysis, and time‐resolved spectroscopy on vesicle‐embedded [FeFe]hydrogenase mimics, driven by a ruthenium tris‐2,2′‐bipyridine photosensitizer, is reported. The membrane effects encountered can be summarized as follows: the presence of vesicles steers the reactivity of the [FeFe]‐benzodithiolate catalyst towards disproportionation, instead of protonation, due to membrane characteristics, such as providing a constant local effective pH, and concentrating and organizing species inside the membrane. The maximum turnover number is limited by photodegradation of the resting state in the catalytic cycle. Understanding these fundamental productive and destructive pathways in complex photochemical systems allows progress towards the development of efficient artificial leaves.
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Affiliation(s)
- René Becker
- van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, Amsterdam, 1098 XH, The Netherlands
| | - Tessel Bouwens
- van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, Amsterdam, 1098 XH, The Netherlands
| | - Esther C F Schippers
- van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, Amsterdam, 1098 XH, The Netherlands
| | - Toon van Gelderen
- van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, Amsterdam, 1098 XH, The Netherlands
| | - Michiel Hilbers
- van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, Amsterdam, 1098 XH, The Netherlands
| | - Sander Woutersen
- van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, Amsterdam, 1098 XH, The Netherlands
| | - Joost N H Reek
- van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, Amsterdam, 1098 XH, The Netherlands
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17
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Gironi B, Lapini A, Ragnoni E, Calvagna C, Paolantoni M, Morresi A, Sassi P. Free volume and dynamics in a lipid bilayer. Phys Chem Chem Phys 2019; 21:23169-23178. [PMID: 31612182 DOI: 10.1039/c9cp03451j] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The lateral diffusion of lipids and of small molecules inside a membrane is strictly related to the arrangement of acyl chains and to their mobility. In this study, we use FTIR and time resolved 2D-IR spectroscopic techniques to characterize the structure and dynamics of the hydrophobic region of palmitoyl-oleylphosphatidylcholine/cholesterol vesicles dispersed in water/dimethylsulfoxide solutions. By means of a non-polar probe, hexacarbonyl tungsten, we monitor the distribution of free volumes inside the bilayer and the conformational dynamics of hydrophobic tails in relation to the different compositions of the membrane or the different compositions of the solvent. Despite the important structural changes induced by the presence of DMSO in the solvating medium, the picosecond dynamics of the membrane is preserved under the different conditions.
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Affiliation(s)
- Beatrice Gironi
- Dipartimento di Chimica, Biologia e Biotecnologie, Università di Perugia, Via Elce di Sotto 8, 06123 Perugia, Italy.
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18
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Jin W, Al-Dulaymi M, Badea I, Leary SC, Rehman J, El-Aneed A. Cellular Uptake and Distribution of Gemini Surfactant Nanoparticles Used as Gene Delivery Agents. AAPS JOURNAL 2019; 21:98. [PMID: 31388860 DOI: 10.1208/s12248-019-0367-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Accepted: 07/15/2019] [Indexed: 12/14/2022]
Abstract
Gemini surfactants are promising molecules utilized as non-viral gene delivery vectors. However, little is known about their cellular uptake and distribution after they release their therapeutic cargo. Therefore, we quantitatively evaluated the cellular uptake and distribution of three gemini surfactants: unsubstituted (16-3-16), with pyridinium head groups (16(Py)-S-2-S-16(Py)) and substituted with a glycyl-lysine di-peptide (16-7N(GK)-16). We also assessed the relationship between cellular uptake and distribution of each gemini surfactant and its overall efficiency and toxicity. Epidermal keratinocytes PAM 212 were treated with gemini surfactant nanoparticles formulated with plasmid DNA and harvested at various time points to collect the enriched nuclear, mitochondrial, plasma membrane, and cytosolic fractions. Gemini surfactants were then extracted from each subcellular fraction and quantified using a validated flow injection analysis-tandem mass spectrometry (FIA-MS/MS) method. Mass spectrometry is superior to the use of fluorescent tags that alter the physicochemical properties and pharmacokinetics of the nanoparticles and can be cleaved from the gemini surfactant molecules within biological systems. Overall, a significantly higher cellular uptake was observed for 16-7N(GK)-16 (17.0%) compared with 16-3-6 (3.6%) and 16(Py)-S-2-S-16(Py) (1.4%), which explained the relatively higher transfection efficiency of 16-7N(GK)-16. Gemini surfactants 16-3-16 and 16(Py)-S-2-S-16(Py) displayed similar subcellular distribution patterns, with major accumulation in the nucleus, followed by the mitochondrion, cytosol, and plasma membrane. In contrast, 16-7N(GK)-16 was relatively evenly distributed across all four subcellular fractions. However, accumulation within the nucleus after 5 h of treatment was the highest for 16(Py)-S-2-S-16(Py) (50.3%), followed by 16-3-16 (41.8%) and then 16-7N(GK)-16 (33.4%), possibly leading to its relatively higher toxicity. Graphical Abstract.
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Affiliation(s)
- Wei Jin
- Drug Design & Discovery Group, College of Pharmacy and Nutrition, University of Saskatchewan, 107 Wiggins Road, Saskatoon, Saskatchewan, S7N 5E5, Canada
| | - Mays Al-Dulaymi
- Drug Design & Discovery Group, College of Pharmacy and Nutrition, University of Saskatchewan, 107 Wiggins Road, Saskatoon, Saskatchewan, S7N 5E5, Canada
| | - Ildiko Badea
- Drug Design & Discovery Group, College of Pharmacy and Nutrition, University of Saskatchewan, 107 Wiggins Road, Saskatoon, Saskatchewan, S7N 5E5, Canada
| | - Scot C Leary
- Department of Biochemistry, Microbiology and Immunology, University of Saskatchewan, 107 Wiggins Road, Saskatoon, Saskatchewan, S7N 5E5, Canada
| | - Jeveria Rehman
- Department of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, Saskatchewan, S7N 5C9, Canada
| | - Anas El-Aneed
- Drug Design & Discovery Group, College of Pharmacy and Nutrition, University of Saskatchewan, 107 Wiggins Road, Saskatoon, Saskatchewan, S7N 5E5, Canada.
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19
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Schott-Verdugo S, Gohlke H. PACKMOL-Memgen: A Simple-To-Use, Generalized Workflow for Membrane-Protein-Lipid-Bilayer System Building. J Chem Inf Model 2019; 59:2522-2528. [PMID: 31120747 DOI: 10.1021/acs.jcim.9b00269] [Citation(s) in RCA: 102] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We present PACKMOL-Memgen, a simple-to-use, generalized workflow for automated building of membrane-protein-lipid-bilayer systems based on open-source tools including Packmol, memembed, pdbremix, and AmberTools. Compared with web-interface-based related tools, PACKMOL-Memgen allows setup of multiple configurations of a system in a user-friendly and efficient manner within minutes. The generated systems are well-packed and thus well-suited as starting configurations in MD simulations under periodic boundary conditions, requiring only moderate equilibration times. PACKMOL-Memgen is distributed with AmberTools and runs on most computing platforms, and its output can also be used for CHARMM or adapted to other molecular-simulation packages.
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Affiliation(s)
- Stephan Schott-Verdugo
- Institute for Pharmaceutical and Medicinal Chemistry , Heinrich Heine University Düsseldorf , 40225 Düsseldorf , Germany.,Centro de Bioinformática y Simulación Molecular (CBSM), Faculty of Engineering , Universidad de Talca , 1 Poniente 1141 , Casilla 721 , Talca , Chile
| | - Holger Gohlke
- Institute for Pharmaceutical and Medicinal Chemistry , Heinrich Heine University Düsseldorf , 40225 Düsseldorf , Germany.,John von Neumann Institute for Computing (NIC), Jülich Supercomputing Centre (JSC) & Institute for Complex Systems-Structural Biochemistry (ICS 6) , Forschungszentrum Jülich GmbH , 52425 Jülich , Germany
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20
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Nagle JF, Venable RM, Maroclo-Kemmerling E, Tristram-Nagle S, Harper PE, Pastor RW. Revisiting Volumes of Lipid Components in Bilayers. J Phys Chem B 2019; 123:2697-2709. [PMID: 30836006 DOI: 10.1021/acs.jpcb.8b12010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In addition to obtaining the highly precise volumes of lipids in lipid bilayers, it has been desirable to obtain the volumes of parts of each lipid, such as the methylenes and terminal methyls on the hydrocarbon chains and the head group. Obtaining such component volumes from experiment and from simulations is re-examined, first by distinguishing methods based on apparent versus partial molar volumes. Although somewhat different, both these methods give results that are counterintuitive and that differ from results obtained by a more local method that can only be applied to simulations. These comparisons reveal differences in the average methylene component volume that result in larger differences in the head group component volumes. Literature experimental volume data for unsaturated phosphocholines and for alkanes have been used and new data have been acquired for saturated phosphocholines. Data and simulations cover extended ranges of temperature to assess both the temperature and chain length dependence of the component volumes. A new method to refine the determination of component volumes is proposed that uses experimental data for different chain lengths at temperatures guided by the temperature dependence determined in simulations. These refinements enable more precise comparisons of the component volumes of different lipids and alkanes in different phases. Finally, the notion of free volume is extended to components using the Lennard-Jones radii to estimate the excluded volume of each component. This analysis reveals that head group free volumes are relatively independent of thermodynamic phase, whereas both the methylene and methyl free volumes increase dramatically when bilayers transition from gel to fluid.
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Affiliation(s)
- John F Nagle
- Department of Physics , Carnegie Mellon University , Pittsburgh , Pennsylvania 15213 , United States
| | - Richard M Venable
- Laboratory of Computational Biology , National Heart, Lung, and Blood Institute, National Institutes of Health , Bethesda , Maryland 20892 , United States
| | | | - Stephanie Tristram-Nagle
- Department of Physics , Carnegie Mellon University , Pittsburgh , Pennsylvania 15213 , United States
| | - Paul E Harper
- Department of Physics & Astronomy , Calvin College , Grand Rapids , Michigan 49546 , United States
| | - Richard W Pastor
- Laboratory of Computational Biology , National Heart, Lung, and Blood Institute, National Institutes of Health , Bethesda , Maryland 20892 , United States
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21
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Effects of oxidation on the physicochemical properties of polyunsaturated lipid membranes. J Colloid Interface Sci 2019; 538:404-419. [DOI: 10.1016/j.jcis.2018.12.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Revised: 11/29/2018] [Accepted: 12/02/2018] [Indexed: 12/13/2022]
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22
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Stachura SS, Malajczuk CJ, Kuprusevicius E, Mancera RL. Influence of Bilayer Size and Number in Multi-Bilayer DOPC Simulations at Full and Low Hydration. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:2399-2411. [PMID: 30632763 DOI: 10.1021/acs.langmuir.8b03212] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Biophysical studies of model cell membranes at full and low hydration are usually carried out using scattering measurements on multi-bilayer systems. Molecular simulations of lipid bilayers aimed at reproducing those experimental conditions are usually conducted using single bilayers with different amounts of water. These simulation conditions may lead to artifacts arising from size effects and self-interactions because of periodic boundary conditions. We have tested the influence of the size and number of bilayers on membrane properties using the Lipid14 force field for lipids in molecular dynamics simulations of 1,2-dioleoyl- sn-glycero-3-phosphocholine bilayers at full hydration (44 water molecules per lipid), low hydration (18 water molecules per lipid), and dehydration (9 water molecules per lipid). A number of additional simulations were conducted with the Slipids force field for comparison. We have found that the average area per lipid (APL), thickness, mass density profiles, and acyl tail order parameters are insensitive to the size and the number of bilayers for all hydration states. The Lipid14 force field can also successfully reproduce the experimentally observed decrease in APL and corresponding increase in bilayer thickness upon dehydration, reflecting the increase in ordering as the system becomes more gel-like. Additionally, decreasing hydration levels were associated with a trend away from normal lateral diffusion and toward more subdiffusive regimes across both force fields. In summary, at least for the Lipid14 force field, the use of a single bilayer with 128 phospholipid molecules provides an adequate representation of multi-bilayer systems at varying levels of hydration.
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Affiliation(s)
- Sławomir S Stachura
- School of Pharmacy and Biomedical Sciences, Curtin Health Innovation Research Institute and Curtin Institute for Computation , Curtin University , GPO Box U1987, Perth , Western Australia 6845 , Australia
| | - Chris J Malajczuk
- School of Pharmacy and Biomedical Sciences, Curtin Health Innovation Research Institute and Curtin Institute for Computation , Curtin University , GPO Box U1987, Perth , Western Australia 6845 , Australia
| | - Egidijus Kuprusevicius
- School of Pharmacy and Biomedical Sciences, Curtin Health Innovation Research Institute and Curtin Institute for Computation , Curtin University , GPO Box U1987, Perth , Western Australia 6845 , Australia
| | - Ricardo L Mancera
- School of Pharmacy and Biomedical Sciences, Curtin Health Innovation Research Institute and Curtin Institute for Computation , Curtin University , GPO Box U1987, Perth , Western Australia 6845 , Australia
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23
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Pedersen JN, Jiang Z, Christiansen G, Lee JC, Pedersen JS, Otzen DE. Lysophospholipids induce fibrillation of the repeat domain of Pmel17 through intermediate core-shell structures. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2018; 1867:519-528. [PMID: 30471451 DOI: 10.1016/j.bbapap.2018.11.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 11/02/2018] [Accepted: 11/17/2018] [Indexed: 11/26/2022]
Abstract
Lipids often play an important role in the initial steps of fibrillation. The melanosomal protein Pmel17 forms amyloid in vivo and contains a highly amyloidogenic Repeat domain (RPT), important for melanin biosynthesis. RPT fibrillation is influenced by two lysolipids, the anionic lysophosphatidylglycerol (LPG) and zwitterionic lysophosphatidylcholine (LPC), both present in vivo at elevated concentrations in melanosomes, organelles in which Pmel17 aggregate. Here we investigate the interaction of RPT with both LPG and LPC using small-angle X-ray scattering (SAXS), isothermal titration calorimetry (ITC), electron microscopy, fluorescence and circular dichroism (CD) spectroscopy. Under non-shaking conditions, both lipids promote fibrillation but this is driven by different interactions with RPT. Each RPT binds >40 LPG molecules but only weak interactions are seen with LPC. Above LPG's criticial micelle concentration (cmc), LPG and RPT form connected micelles where RPT binds to the surface as beads on a string with core-shell structures. Binding to LPG only induces α-helical structure well above the cmc, while LPC has no measurable effect on the protein structure. While low (but still super-cmc) concentrations of LPG strongly promote aggregation, at higher LPG concentrations (10 mM), only ~ one RPT binds per micelle, inhibiting amyloid formation. ITC and SAXS reveal some interactions between the zwitterionic lipid LPC and RPT below the cmc but little above the cmc. Nevertheless, LPC only promotes aggregation above the cmc and this process is not inhibited by high LPC concentrations, suggesting that monomers and micelles cooperate to influence amyloid formation.
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Affiliation(s)
- Jannik Nedergaard Pedersen
- Interdisciplinary Nanoscience Center (iNANO), Department of Chemistry, Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus, Denmark
| | - Zhiping Jiang
- Laboratory of Protein Conformation and Dynamics, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892-8013, USA
| | - Gunna Christiansen
- Department of Biomedicine, Aarhus University, Wilhelm Meyers Allé 4, DK-8000 Aarhus, Denmark
| | - Jennifer C Lee
- Laboratory of Protein Conformation and Dynamics, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892-8013, USA
| | - Jan Skov Pedersen
- Interdisciplinary Nanoscience Center (iNANO), Department of Chemistry, Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus, Denmark.
| | - Daniel E Otzen
- Interdisciplinary Nanoscience Center (iNANO), Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 14, DK-8000 Aarhus, Denmark.
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24
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Insight into the molecular mechanism behind PEG-mediated stabilization of biofluid lipases. Sci Rep 2018; 8:12293. [PMID: 30115948 PMCID: PMC6095910 DOI: 10.1038/s41598-018-29871-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 07/18/2018] [Indexed: 01/26/2023] Open
Abstract
Bioconjugates established between anionic polyethylene glycol (PEG) based polymers and cationic proteins have proven to be a promising strategy to engineer thermostable biocatalysts. However, the enzyme activity of these bioconjugates is very low and the mechanism of non-covalent PEG-stabilization is yet to be understood. This work presents experimental and molecular dynamics simulation studies, using lipase-polymer surfactant nanoconjugates from mesophile Rhizomucor miehei (RML), performed to evaluate the effect of PEG on enzyme stability and activity. Results demonstrated that the number of hydrogen bonds between the cationized RML and PEG chain correlates with enzyme thermostability. In addition, an increase of both the number of PEG-polymers units and cationization degree of the enzyme leads to a decrease of enzyme activity. Modelling with SAXS data of aqueous solutions of the biofluid lipases agrees with previous hypothesis that these enzymes contain a core constituted of folded protein confined by a shell of surfactants. Together results provide valuable insight into the mechanism of non-covalent PEG mediated protein stabilization relevant for engineering active and thermostable biofluids. Furthermore, the first biofluids RML with activity comparable to their cationized counterpart are presented.
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25
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Nagao M, Kelley EG, Ashkar R, Bradbury R, Butler PD. Probing Elastic and Viscous Properties of Phospholipid Bilayers Using Neutron Spin Echo Spectroscopy. J Phys Chem Lett 2017; 8:4679-4684. [PMID: 28892394 DOI: 10.1021/acs.jpclett.7b01830] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The elastic and viscous properties of self-assembled amphiphilic membranes dictate the intricate hierarchy of their structure and dynamics ranging from the diffusion of individual molecules to the large-scale deformation of the membrane. We previously demonstrated that neutron spin echo spectroscopy measurements of model amphiphilic membranes can access the naturally occurring submicrosecond membrane motions, such as bending and thickness fluctuations. Here we show how the experimentally measured fluctuation parameters can be used to determine the inherent membrane properties and demonstrate how membrane viscosity and compressibility modulus are influenced by lipid composition in a series of simple phosphatidylcholine bilayers with different tail lengths as a function of temperature. This approach highlights the interdependence of the bilayer elastic and viscous properties and the collective membrane dynamics and opens new avenues to investigating the mechanical properties of more complex and biologically inspired systems.
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Affiliation(s)
- Michihiro Nagao
- NIST Center for Neutron Research, National Institute of Standards and Technology , Gaithersburg, Maryland 20899, United States
- Center for Exploration of Energy and Matter, Department of Physics, Indiana University , Bloomington, Indiana 47408, United States
| | - Elizabeth G Kelley
- NIST Center for Neutron Research, National Institute of Standards and Technology , Gaithersburg, Maryland 20899, United States
| | - Rana Ashkar
- Biology and Soft Matter Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - Robert Bradbury
- NIST Center for Neutron Research, National Institute of Standards and Technology , Gaithersburg, Maryland 20899, United States
- Center for Exploration of Energy and Matter, Department of Physics, Indiana University , Bloomington, Indiana 47408, United States
| | - Paul D Butler
- NIST Center for Neutron Research, National Institute of Standards and Technology , Gaithersburg, Maryland 20899, United States
- Department of Chemical & Biomolecular Engineering, University of Delaware , Newark, Delaware 19716, United States
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26
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Heberle FA, Pabst G. Complex biomembrane mimetics on the sub-nanometer scale. Biophys Rev 2017; 9:353-373. [PMID: 28717925 PMCID: PMC5578918 DOI: 10.1007/s12551-017-0275-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Accepted: 06/26/2017] [Indexed: 12/12/2022] Open
Abstract
Biomimetic lipid vesicles are indispensable tools for gaining insight into the biophysics of cell physiology on the molecular level. The level of complexity of these model systems has steadily increased, and now spans from domain-forming lipid mixtures to asymmetric lipid bilayers. Here, we review recent progress in the development and application of elastic neutron and X-ray scattering techniques for studying these systems in situ and under physiologically relevant conditions on the nanometer to sub-nanometer length scales. In particular, we focus on: (1) structural details of coexisting liquid-ordered and liquid-disordered domains, including their thickness and lipid packing mismatch as a function of a size transition from nanoscopic to macroscopic domains; (2) membrane-mediated protein partitioning into lipid domains; (3) the role of the aqueous medium in tuning interactions between membranes and domains; and (4) leaflet-specific structure in asymmetric bilayers and passive lipid flip-flop.
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Affiliation(s)
- Frederick A Heberle
- The Bredesen Center, University of Tennessee, Knoxville, TN, 37996, USA.,Joint Institute for Biological Sciences and Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Georg Pabst
- Institute of Molecular Biosciences, Biophysics Division, NAWI Graz, University of Graz, 8010, Graz, Austria. .,BioTechMed-Graz, 8010, Graz, Austria.
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27
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Sørensen HV, Pedersen JN, Pedersen JS, Otzen DE. Tailoring thermal treatment to form liprotide complexes between oleic acid and different proteins. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2017; 1865:682-693. [DOI: 10.1016/j.bbapap.2017.03.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 03/05/2017] [Accepted: 03/24/2017] [Indexed: 10/19/2022]
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28
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West JD, Zhu Y, Saem S, Moran-Mirabal J, Hitchcock AP. X-ray Absorption Spectroscopy and Spectromicroscopy of Supported Lipid Bilayers. J Phys Chem B 2017; 121:4492-4501. [DOI: 10.1021/acs.jpcb.7b02646] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Jonathan D. West
- Department of Chemistry and
Chemical Biology, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - Yujie Zhu
- Department of Chemistry and
Chemical Biology, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - Sokunthearath Saem
- Department of Chemistry and
Chemical Biology, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - Jose Moran-Mirabal
- Department of Chemistry and
Chemical Biology, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - Adam P. Hitchcock
- Department of Chemistry and
Chemical Biology, McMaster University, Hamilton, Ontario L8S 4M1, Canada
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29
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Eicher B, Heberle FA, Marquardt D, Rechberger GN, Katsaras J, Pabst G. Joint small-angle X-ray and neutron scattering data analysis of asymmetric lipid vesicles. J Appl Crystallogr 2017; 50:419-429. [PMID: 28381971 PMCID: PMC5377341 DOI: 10.1107/s1600576717000656] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 01/12/2017] [Indexed: 11/10/2022] Open
Abstract
Low- and high-resolution models describing the internal transbilayer structure of asymmetric lipid vesicles have been developed. These models can be used for the joint analysis of small-angle neutron and X-ray scattering data. The models describe the underlying scattering length density/electron density profiles either in terms of slabs or through the so-called scattering density profile, previously applied to symmetric lipid vesicles. Both models yield structural details of asymmetric membranes, such as the individual area per lipid, and the hydrocarbon thickness of the inner and outer bilayer leaflets. The scattering density profile model, however, comes at a cost of increased computational effort but results in greater structural resolution, showing a slightly lower packing of lipids in the outer bilayer leaflet of ∼120 nm diameter palmitoyl-oleoyl phosphatidyl-choline (POPC) vesicles, compared to the inner leaflet. Analysis of asymmetric dipalmitoyl phosphatidylcholine/POPC vesicles did not reveal evidence of transbilayer coupling between the inner and outer leaflets at 323 K, i.e. above the melting transition temperature of the two lipids.
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Affiliation(s)
- Barbara Eicher
- Instiute of Molecular Biosciences, Biophysics Division, University of Graz, Austria; BioTechMed-Graz, Graz, 8010, Austria
| | - Frederick A Heberle
- The Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, TN, USA; Joint Institute for Biological Sciences, Oak Ridge National Laboratory, Oak Ridge, TN, USA; Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Drew Marquardt
- Instiute of Molecular Biosciences, Biophysics Division, University of Graz, Austria; BioTechMed-Graz, Graz, 8010, Austria
| | - Gerald N Rechberger
- Instiute of Molecular Biosciences, University of Graz, Austria; Omics-Center Graz, BioTechMed-Graz, Austria
| | - John Katsaras
- Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA; Shull Wollan Center, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Georg Pabst
- Instiute of Molecular Biosciences, Biophysics Division, University of Graz, Austria; BioTechMed-Graz, Graz, 8010, Austria
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30
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Litz JP, Thakkar N, Portet T, Keller SL. Depletion with Cyclodextrin Reveals Two Populations of Cholesterol in Model Lipid Membranes. Biophys J 2017; 110:635-645. [PMID: 26840728 DOI: 10.1016/j.bpj.2015.11.021] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Revised: 11/06/2015] [Accepted: 11/10/2015] [Indexed: 10/22/2022] Open
Abstract
Recent results provide evidence that cholesterol is highly accessible for removal from both cell and model membranes above a threshold concentration that varies with membrane composition. Here we measured the rate at which methyl-β-cyclodextrin depletes cholesterol from a supported lipid bilayer as a function of cholesterol mole fraction. We formed supported bilayers from two-component mixtures of cholesterol and a PC (phosphatidylcholine) lipid, and we directly visualized the rate of decrease in area of the bilayers with fluorescence microscopy. Our technique yields the accessibility of cholesterol over a wide range of concentrations (30-66 mol %) for many individual bilayers, enabling fast acquisition of replicate data. We found that the bilayers contain two populations of cholesterol, one with low surface accessibility and the other with high accessibility. A larger fraction of the total membrane cholesterol appears in the more accessible population when the acyl chains of the PC-lipid tails are more unsaturated. Our findings are most consistent with the predictions of the condensed-complex and cholesterol bilayer domain models of cholesterol-phospholipid interactions in lipid membranes.
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Affiliation(s)
- Jonathan P Litz
- Department of Chemistry, University of Washington, Seattle, Washington
| | - Niket Thakkar
- Department of Chemistry, University of Washington, Seattle, Washington; Department of Applied Mathematics, University of Washington, Seattle, Washington
| | - Thomas Portet
- Department of Chemistry, University of Washington, Seattle, Washington
| | - Sarah L Keller
- Department of Chemistry, University of Washington, Seattle, Washington; Department of Physics, University of Washington, Seattle, Washington.
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31
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An extensive simulation study of lipid bilayer properties with different head groups, acyl chain lengths, and chain saturations. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:3093-3104. [PMID: 27664502 DOI: 10.1016/j.bbamem.2016.09.016] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 09/14/2016] [Accepted: 09/19/2016] [Indexed: 12/21/2022]
Abstract
Previous MD simulations of six phosphocholine (PC) lipid bilayers demonstrated the accuracy of the CHARMM36 force field (C36FF) for PC bilayer simulation at varied temperatures (BBA-Biomembranes, 1838 (2014): 2520-2529). In this work, we further examine the accuracy of C36FF over a wide temperature range for a broader range of lipid types such as various head groups (phosphatidic acid (PA), PC, phosphoethanolamine (PE), phosphoglycerol (PG), and phosphoserine (PS)), and tails (saturated, mono-, mixed- and poly-unsaturated acyl chains with varied chain lengths). The structural properties (surface area per lipid (SA/lip), overall bilayer thickness, hydrophobic thickness, headgroup-to-headgroup thickness, deuterium order parameter (SCD), and spin-lattice relaxation time (T1)) obtained from simulations agree well with nearly all available experimental data. Our analyses indicate that PS lipids have the most inter-lipid hydrogen bonds, while PG lipids have the most intra-lipid hydrogen bonds, which play the main role in their low SA/lip in PS lipids and low thicknesses in PG lipids, respectively. PS, PE, and PA lipids have the largest contact clusters with on average 5-8 lipids per cluster, while PC and PG have clusters of 4 lipids based on a cutoff distance of 6.5Å. PS lipids have much slower lipid wobble (i.e., higher correlation time) than other head groups at a given temperature as the hydrogen bonded network significantly reduces a lipid's mobility, and the rate of lipid wobble increases dramatically as temperature increases. These in-depth analyses facilitate further understanding of lipid bilayers at the atomic level.
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32
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Heftberger P, Kollmitzer B, Rieder AA, Amenitsch H, Pabst G. In situ determination of structure and fluctuations of coexisting fluid membrane domains. Biophys J 2015; 108:854-862. [PMID: 25692590 PMCID: PMC4336378 DOI: 10.1016/j.bpj.2014.11.3488] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Revised: 11/19/2014] [Accepted: 11/24/2014] [Indexed: 11/28/2022] Open
Abstract
Biophysical understanding of membrane domains requires accurate knowledge of their structural details and elasticity. We report on a global small angle x-ray scattering data analysis technique for coexisting liquid-ordered (Lo) and liquid-disordered (Ld) domains in fully hydrated multilamellar vesicles. This enabled their detailed analysis for differences in membrane thickness, area per lipid, hydrocarbon chain length, and bending fluctuation as demonstrated for two ternary mixtures (DOPC/DSPC/CHOL and DOPC/DPPC/CHOL) at different cholesterol concentrations. Lo domains were found to be ∼10 Å thicker, and laterally up to 20 Å2/lipid more condensed than Ld domains. Their bending fluctuations were also reduced by ∼65%. Increase of cholesterol concentration caused significant changes in structural properties of Ld, while its influence on Lo properties was marginal. We further observed that temperature-induced melting of Lo domains is associated with a diffusion of cholesterol to Ld domains and controlled by Lo/Ld thickness differences.
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Affiliation(s)
- Peter Heftberger
- Biophysics Division, Institute of Molecular Biosciences, University of Graz, NAWI Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria
| | - Benjamin Kollmitzer
- Biophysics Division, Institute of Molecular Biosciences, University of Graz, NAWI Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria
| | - Alexander A Rieder
- Biophysics Division, Institute of Molecular Biosciences, University of Graz, NAWI Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria
| | - Heinz Amenitsch
- Institute of Inorganic Chemistry, Graz University of Technology, Graz, Austria
| | - Georg Pabst
- Biophysics Division, Institute of Molecular Biosciences, University of Graz, NAWI Graz, Graz, Austria; BioTechMed-Graz, Graz, Austria.
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33
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Structural Significance of Lipid Diversity as Studied by Small Angle Neutron and X-ray Scattering. MEMBRANES 2015; 5:454-72. [PMID: 26402708 PMCID: PMC4584290 DOI: 10.3390/membranes5030454] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 09/15/2015] [Indexed: 11/17/2022]
Abstract
We review recent developments in the rapidly growing field of membrane biophysics, with a focus on the structural properties of single lipid bilayers determined by different scattering techniques, namely neutron and X-ray scattering. The need for accurate lipid structural properties is emphasized by the sometimes conflicting results found in the literature, even in the case of the most studied lipid bilayers. Increasingly, accurate and detailed structural models require more experimental data, such as those from contrast varied neutron scattering and X-ray scattering experiments that are jointly refined with molecular dynamics simulations. This experimental and computational approach produces robust bilayer structural parameters that enable insights, for example, into the interplay between collective membrane properties and its components (e.g., hydrocarbon chain length and unsaturation, and lipid headgroup composition). From model studies such as these, one is better able to appreciate how a real biological membrane can be tuned by balancing the contributions from the lipid's different moieties (e.g., acyl chains, headgroups, backbones, etc.).
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34
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Gallová J, Klacsová M, Devínsky F, Balgavý P. Partial volumes of cholesterol and monounsaturated diacylphosphatidylcholines in mixed bilayers. Chem Phys Lipids 2015; 190:1-8. [DOI: 10.1016/j.chemphyslip.2015.06.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Revised: 05/20/2015] [Accepted: 06/15/2015] [Indexed: 10/23/2022]
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Abstract
Dengue virus (DENV) is an important human pathogen causing millions of disease cases and thousands of deaths worldwide. Non-structural protein 4A (NS4A) is a vital component of the viral replication complex (RC) and plays a major role in the formation of host cell membrane-derived structures that provide a scaffold for replication. The N-terminal cytoplasmic region of NS4A(1–48) is known to preferentially interact with highly curved membranes. Here, we provide experimental evidence for the stable binding of NS4A(1–48) to small liposomes using a liposome floatation assay and identify the lipid binding sequence by NMR spectroscopy. Mutations L6E;M10E were previously shown to inhibit DENV replication and to interfere with the binding of NS4A(1–48) to small liposomes. Our results provide new details on the interaction of the N-terminal region of NS4A with membranes and will prompt studies of the functional relevance of the curvature sensitive membrane anchor at the N-terminus of NS4A.
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36
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Kaspersen JD, Pedersen JN, Hansted JG, Nielsen SB, Sakthivel S, Wilhelm K, Nemashkalova EL, Permyakov SE, Permyakov EA, Pinto Oliveira CL, Morozova-Roche LA, Otzen DE, Pedersen JS. Generic structures of cytotoxic liprotides: nano-sized complexes with oleic acid cores and shells of disordered proteins. Chembiochem 2014; 15:2693-702. [PMID: 25403886 DOI: 10.1002/cbic.201402407] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Indexed: 11/05/2022]
Abstract
The cytotoxic complex formed between α-lactalbumin and oleic acid (OA) has inspired many studies on protein-fatty acid complexes, but structural insight remains sparse. After having used small-angle X-ray scattering (SAXS) to obtain structural information, we present a new, generic structural model of cytotoxic protein-oleic acid complexes, which we have termed liprotides (lipids and partially denatured proteins). Twelve liprotides formed from seven structurally unrelated proteins and prepared by different procedures all displayed core-shell structures, each with a micellar OA core and a shell consisting of flexible, partially unfolded protein, which stabilizes the OA micelle. The common structure explains similar effects exerted on cells by different liprotides and is consistent with a cargo off-loading of the OA into cell membranes.
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Affiliation(s)
- Jørn D Kaspersen
- Department of Chemistry and Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds Vej 14, 8000 Aarhus C (Denmark)
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37
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Benedetto A, Heinrich F, Gonzalez MA, Fragneto G, Watkins E, Ballone P. Structure and Stability of Phospholipid Bilayers Hydrated by a Room-Temperature Ionic Liquid/Water Solution: A Neutron Reflectometry Study. J Phys Chem B 2014; 118:12192-206. [DOI: 10.1021/jp507631h] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Antonio Benedetto
- School
of Physics, University College Dublin−UCD, Belfield Campus, Dublin 4, Ireland
| | - Frank Heinrich
- Department
of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
- Center
for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| | | | | | - Erik Watkins
- Institute Laue-Langevin, Grenoble, France
- Lujan
Neutron Scattering Center, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, United States
| | - Pietro Ballone
- Center
for Life Nano Science @Sapienza, Istituto Italiano di Tecnologia (IIT), 00161 Roma, Italy
- Department
of Physics, Universita’ di Roma “La Sapienza”, 00185 Roma, Italy
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38
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Effect of the cosolutes trehalose and methanol on the equilibrium and phase-transition properties of glycerol-monopalmitate lipid bilayers investigated using molecular dynamics simulations. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2014; 43:517-44. [DOI: 10.1007/s00249-014-0982-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 07/16/2014] [Accepted: 07/24/2014] [Indexed: 10/24/2022]
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39
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A systematic molecular dynamics simulation study of temperature dependent bilayer structural properties. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:2520-9. [PMID: 24953542 DOI: 10.1016/j.bbamem.2014.06.010] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2014] [Revised: 06/07/2014] [Accepted: 06/11/2014] [Indexed: 11/21/2022]
Abstract
Although lipid force fields (FFs) used in molecular dynamics (MD) simulations have proved to be accurate, there has not been a systematic study on their accuracy over a range of temperatures. Motivated by the X-ray and neutron scattering measurements of common phosphatidylcholine (PC) bilayers (Kučerka et al. BBA. 1808: 2761, 2011), the CHARMM36 (C36) FF accuracy is tested in this work with MD simulations of six common PC lipid bilayers over a wide range of temperatures. The calculated scattering form factors and deuterium order parameters from the C36 MD simulations agree well with the X-ray, neutron, and NMR experimental data. There is excellent agreement between MD simulations and experimental estimates for the surface area per lipid, bilayer thickness (DB), hydrophobic thickness (DC), and lipid volume (VL). The only minor discrepancy between simulation and experiment is a measure of (DB-DHH)/2 where DHH is the distance between the maxima in the electron density profile along the bilayer normal. Additional MD simulations with pure water and heptane over a range of temperatures provide explanations of possible reasons causing the minor deviation. Overall, the C36 FF is accurate for use with liquid crystalline PC bilayers of varying chain types and over biologically relevant temperatures.
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40
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Belička M, Klacsová M, Karlovská J, Westh P, Devínsky F, Balgavý P. Molecular and component volumes of N,N-dimethyl-N-alkylamine N-oxides in DOPC bilayers. Chem Phys Lipids 2014; 180:1-6. [DOI: 10.1016/j.chemphyslip.2014.02.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2013] [Revised: 02/19/2014] [Accepted: 02/21/2014] [Indexed: 11/28/2022]
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41
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Murugova TN, Balgavý P. Molecular volumes of DOPC and DOPS in mixed bilayers of multilamellar vesicles. Phys Chem Chem Phys 2014; 16:18211-6. [DOI: 10.1039/c4cp01980f] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Specific volume of 1,2-dioleoyl-sn-glycero-3-phosphocholine and 1,2-dioleoyl-sn-glycero-3-phospho-l-serine mixtures in bilayers linearly depends on the molar fraction of the constituents, indicating an ideal volume mixing.
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Affiliation(s)
- T. N. Murugova
- Frank Laboratory of Neutron Physics
- Joint Institute for Nuclear Research
- 141980 Dubna, Russia
- Moscow Institute of Physics and Technology
- 141700 Dolgoprudny, Russia
| | - P. Balgavý
- Department of Physical Chemistry of Drugs
- Faculty of Pharmacy
- Comenius University
- 832 32 Bratislava, Slovakia
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42
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Tchikov V, Fritsch J, Schütze S. Separation of Magnetically Isolated TNF Receptosomes from Mitochondria. Methods Enzymol 2014; 535:327-49. [DOI: 10.1016/b978-0-12-397925-4.00019-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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43
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Quantifying the local tissue volume and composition in individual brains with magnetic resonance imaging. Nat Med 2013; 19:1667-72. [PMID: 24185694 PMCID: PMC3855886 DOI: 10.1038/nm.3390] [Citation(s) in RCA: 196] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Accepted: 02/05/2013] [Indexed: 12/25/2022]
Abstract
We describe a quantitative neuroimaging method to estimate the macromolecular tissue volume (MTV), a fundamental measure of brain anatomy. By making measurements over a range of field strengths and scan parameters, we tested the key assumptions and the robustness of the method. The measurements confirm that a consistent, quantitative estimate of macromolecular volume can be obtained across a range of scanners. MTV estimates are sufficiently precise to enable a comparison between data obtained from an individual subject with control population data. We describe two applications. First, we show that MTV estimates can be combined with T1 and diffusion measurements to augment our understanding of the tissue properties. Second we show that MTV provides a sensitive measure of disease status in individual patients with multiple sclerosis. The MTV maps are obtained using short clinically appropriate scans that can reveal how tissue changes influence behavior and cognition.
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44
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Kinoshita M, Goretta S, Tsuchikawa H, Matsumori N, Murata M. Characterization of the ordered phase formed by sphingomyelin analogues and cholesterol binary mixtures. Biophysics (Nagoya-shi) 2013; 9:37-49. [PMID: 27493539 PMCID: PMC4629689 DOI: 10.2142/biophysics.9.37] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 04/02/2013] [Indexed: 01/24/2023] Open
Abstract
The influences of structural alterations of sphingomyelin (SM) on its interactions with cholesterol (chol) and on ordered phase formation were examined by density measurements and surface pressure vs. molecular area isotherm measurements. In addition, we quantitatively characterized the ordered phase formed in each SM and chol binary mixture on the basis of the molecular compressional modulus of SM (
Cmol−1). Density measurements demonstrated that the ordered phase formation in threo-SM (tSM)/chol and dihydrosphingomyelin (DHSM)/chol binary bilayers shows similar chol concentration-dependency to that of natural erythro-SM (eSM)/chol bilayers; the ordered phase formation was completed in the presence of 25 mol% chol. In contrast, SM bearing a triple bond in the place of a double bond (tripleSM) required a greater concentration of chol to completely transform the bilayer into the ordered phase (at 40 mol% chol). Surface pressure vs. molecular area isotherms showed that the DHSM molecule (
Cmol−1 = 290 mN/m) is more rigid than eSM (
Cmol−1 = 240 mN/m) above 30 mol% chol (in the ordered phase), although these values are similar (140–150 mN/m) in the absence of chol (liquid condensed phase). Most likely, the DHSM/chol mixture forms a more ordered membrane than the eSM/chol mixture does. Moreover, in the absence of chol, the rigidity of the tripleSM molecule (
Cmol−1 = 250 mN/m) is significantly higher as compared with that of the eSM molecule (
Cmol−1 = 150 mN/m), which is probably due to the presence of a triple bond.
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Affiliation(s)
- Masanao Kinoshita
- JST ERATO, Lipid Active Structure Project, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan; Project Research Center for Fundamental Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Sarah Goretta
- Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Hiroshi Tsuchikawa
- Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Nobuaki Matsumori
- JST ERATO, Lipid Active Structure Project, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan; Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
| | - Michio Murata
- JST ERATO, Lipid Active Structure Project, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan; Project Research Center for Fundamental Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan; Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan
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45
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Thompson KC, Jones SH, Rennie AR, King MD, Ward AD, Hughes BR, Lucas COM, Campbell RA, Hughes AV. Degradation and rearrangement of a lung surfactant lipid at the air-water interface during exposure to the pollutant gas ozone. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:4594-4602. [PMID: 23480170 DOI: 10.1021/la304312y] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The presence of unsaturated lipids in lung surfactant is important for proper respiratory function. In this work, we have used neutron reflection and surface pressure measurements to study the reaction of the ubiquitous pollutant gas-phase ozone, O3, with pure and mixed phospholipid monolayers at the air-water interface. The results reveal that the reaction of the unsaturated lipid 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine, POPC, with ozone leads to the rapid loss of the terminal C9 portion of the oleoyl strand of POPC from the air-water interface. The loss of the C9 portion from the interface is accompanied by an increase in the surface pressure (decrease in surface tension) of the film at the air-water interface. The results suggest that the portion of the oxidized oleoyl strand that is still attached to the lipid headgroup rapidly reverses its orientation and penetrates the air-water interface alongside the original headgroup, thus increasing the surface pressure. The reaction of POPC with ozone also leads to a loss of material from the palmitoyl strand, but the loss of palmitoyl material occurs after the loss of the terminal C9 portion from the oleoyl strand of the molecule, suggesting that the palmitoyl material is lost in a secondary reaction step. Further experiments studying the reaction of mixed monolayers composed of unsaturated lipid POPC and saturated lipid dipalmitoyl-sn-glycero-3-phosphocholine, DPPC, revealed that no loss of DPPC from the air-water interface occurs, eliminating the possibility that a reactive species such as an OH radical is formed and is able to attack nearby lipid chains. The reaction of ozone with the mixed films does cause a significant change in the surface pressure of the air-water interface. Thus, the reaction of unsaturated lipids in lung surfactant changes and impairs the physical properties of the film at the air-water interface.
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Affiliation(s)
- Katherine C Thompson
- Department of Biological Sciences and Institute of Structural and Molecular Biology, Birkbeck College, University of London, Malet Street, London WC1E 7HX, UK
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46
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Damas C, Carcenac Y, Abarbri M, Coudert R. Synthesis and physicochemical properties of unsaturated trifluoromethylated sodium carboxylates in aqueous media. J Colloid Interface Sci 2013; 395:119-26. [DOI: 10.1016/j.jcis.2012.11.060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2012] [Revised: 11/27/2012] [Accepted: 11/28/2012] [Indexed: 10/27/2022]
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47
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Teague WE, Soubias O, Petrache H, Fuller N, Hines KG, Rand RP, Gawrisch K. Elastic properties of polyunsaturated phosphatidylethanolamines influence rhodopsin function. Faraday Discuss 2013; 161:383-459. [PMID: 23805751 PMCID: PMC3703878 DOI: 10.1039/c2fd20095c] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/18/2023]
Abstract
Membranes with a high content of polyunsaturated phosphatidylethanolamines (PE) facilitate formation of metarhodopsin-II (M(II)), the photointermediate of bovine rhodopsin that activates the G protein transducin. We determined whether M(II)-formation is quantitatively linked to the elastic properties of PEs. Curvature elasticity of monolayers of the polyunsaturated lipids 18 : 0-22 : 6(n - 3)PE, 18 : 0-22 : 5(n)- 6PE and the model lipid 18 : 1(n - 9)-18 : 1,(n- 9)PE were investigated in the inverse hexagonal phase. All three lipids form lipid monolayers with rather low spontaneous radii of curvature of 26-28 angstroms. In membranes, all three PEs generate high negative curvature elastic stress that shifts the equilibrium of MI(I)/M(II) photointermediates of rhodopsin towards M(II) formation.
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Affiliation(s)
- Walter E. Teague
- Laboratory of Membrane Biochemistry and Biophysics, NIAAA, NIH, Bethesda, MD 20892, USA. Fax: +1-301-594-0035; Tel: +1-301-594-3750
| | - Olivier Soubias
- Laboratory of Membrane Biochemistry and Biophysics, NIAAA, NIH, Bethesda, MD 20892, USA. Fax: +1-301-594-0035; Tel: +1-301-594-3750
| | - Horia Petrache
- Department of Physics, Indiana Univ.- Perdue Univ., Indianapolis, IN 46202, USA. Fax: +1-317-274-2392; Tel: +1-317-278-6521
| | - Nola Fuller
- Dept. Biol. Sci., Brock Univ., St. Catharines, Ont. L2S 3A1, Canada. Phone:+1-905-688-5550 ext.3388
| | - Kirk G. Hines
- Laboratory of Membrane Biochemistry and Biophysics, NIAAA, NIH, Bethesda, MD 20892, USA. Fax: +1-301-594-0035; Tel: +1-301-594-3750
| | - R. Peter Rand
- Dept. Biol. Sci., Brock Univ., St. Catharines, Ont. L2S 3A1, Canada. Phone:+1-905-688-5550 ext.3388
| | - Klaus Gawrisch
- Laboratory of Membrane Biochemistry and Biophysics, NIAAA, NIH, Bethesda, MD 20892, USA. Fax: +1-301-594-0035; Tel: +1-301-594-3750
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Goretta SA, Kinoshita M, Mori S, Tsuchikawa H, Matsumori N, Murata M. Effects of chemical modification of sphingomyelin ammonium group on formation of liquid-ordered phase. Bioorg Med Chem 2012; 20:4012-9. [DOI: 10.1016/j.bmc.2012.05.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Revised: 05/08/2012] [Accepted: 05/08/2012] [Indexed: 12/21/2022]
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Mixed aggregate formation in gemini surfactant/1,2-dialkyl-sn-glycero-3-phosphoethanolamine systems. J Colloid Interface Sci 2012; 377:237-43. [DOI: 10.1016/j.jcis.2012.03.048] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Revised: 03/15/2012] [Accepted: 03/16/2012] [Indexed: 01/30/2023]
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Kimura T, Yeliseev AA, Vukoti K, Rhodes SD, Cheng K, Rice KC, Gawrisch K. Recombinant cannabinoid type 2 receptor in liposome model activates g protein in response to anionic lipid constituents. J Biol Chem 2012; 287:4076-87. [PMID: 22134924 PMCID: PMC3281699 DOI: 10.1074/jbc.m111.268425] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2011] [Revised: 11/29/2011] [Indexed: 11/06/2022] Open
Abstract
Human cannabinoid type 2 (CB(2)) receptor expressed in Escherichia coli was purified and successfully reconstituted in the functional form into lipid bilayers composed of POPC, 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine, 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-L-serine (POPS), and cholesteryl hemisuccinate (CHS). Reconstitution was performed by detergent removal from the protein/lipid/detergent mixed micelles either on an adsorbent column, or by rapid dilution to below the critical micelle concentration of detergent followed by removal of detergent monomers on a concentrator. Proteoliposomes prepared at a protein/phospholipid/CHS molar ratio of 1/620-650/210-220 are free of detergent as shown by (1)H NMR, have a homogeneous protein/lipid ratio shown by isopycnic gradient ultracentrifugation, and are small in size with a mean diameter of 150-200 nm as measured by dynamic light scattering. Functional integrity of the reconstituted receptor was confirmed by quantitative binding of (2)H-labeled agonist CP-55,940-d(6) measured by (2)H magic angle spinning NMR, as well as by activation of G protein. The efficiency of G protein activation by agonist-bound CB(2) receptor was affected by negative electric surface potentials of proteoliposomes controlled by the content of anionic CHS or POPS. The activation was highest at an anionic lipid content of about 50 mol %. There was no correlation between the efficiency of G protein activation and an increase of hydrocarbon chain order induced by CHS or cholesterol. The results suggest the importance of anionic lipids in regulating signal transduction by CB(2) receptor and other class A GPCR. The successful reconstitution of milligram quantities of pure, functional CB(2) receptor enables a wide variety of structural studies.
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Affiliation(s)
- Tomohiro Kimura
- From the Laboratory of Membrane Biochemistry and Biophysics, NIAAA, and
| | | | - Krishna Vukoti
- From the Laboratory of Membrane Biochemistry and Biophysics, NIAAA, and
| | - Steven D. Rhodes
- From the Laboratory of Membrane Biochemistry and Biophysics, NIAAA, and
| | - Kejun Cheng
- the Chemical Biology Research Branch, NIDA and NIAAA, National Institutes of Health, Bethesda, Maryland 20852
| | - Kenner C. Rice
- the Chemical Biology Research Branch, NIDA and NIAAA, National Institutes of Health, Bethesda, Maryland 20852
| | - Klaus Gawrisch
- From the Laboratory of Membrane Biochemistry and Biophysics, NIAAA, and
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