1
|
DiPasquale M, Marquardt D. Perceiving the functions of vitamin E through neutron and X-ray scattering. Adv Colloid Interface Sci 2024; 330:103189. [PMID: 38824717 DOI: 10.1016/j.cis.2024.103189] [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: 10/08/2023] [Revised: 05/14/2024] [Accepted: 05/17/2024] [Indexed: 06/04/2024]
Abstract
Take your vitamins, or don't? Vitamin E is one of the few lipophilic vitamins in the human diet and is considered an essential nutrient. Over the years it has proven to be a powerful antioxidant and is commercially used as such, but this association is far from linear in physiology. It is increasingly more likely that vitamin E has multiple legitimate biological roles. Here, we review past and current work using neutron and X-ray scattering to elucidate the influence of vitamin E on key features of model membranes that can translate to the biological function(s) of vitamin E. Although progress is being made, the hundred year-old mystery remains unsolved.
Collapse
Affiliation(s)
| | - Drew Marquardt
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada; Department of Physics, University of Windsor, Windsor, Ontario, Canada.
| |
Collapse
|
2
|
Caselli L, Conti L, De Santis I, Berti D. Small-angle X-ray and neutron scattering applied to lipid-based nanoparticles: Recent advancements across different length scales. Adv Colloid Interface Sci 2024; 327:103156. [PMID: 38643519 DOI: 10.1016/j.cis.2024.103156] [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: 10/19/2023] [Revised: 02/28/2024] [Accepted: 04/08/2024] [Indexed: 04/23/2024]
Abstract
Lipid-based nanoparticles (LNPs), ranging from nanovesicles to non-lamellar assemblies, have gained significant attention in recent years, as versatile carriers for delivering drugs, vaccines, and nutrients. Small-angle scattering methods, employing X-rays (SAXS) or neutrons (SANS), represent unique tools to unveil structure, dynamics, and interactions of such particles on different length scales, spanning from the nano to the molecular scale. This review explores the state-of-the-art on scattering methods applied to unveil the structure of lipid-based nanoparticles and their interactions with drugs and bioactive molecules, to inform their rational design and formulation for medical applications. We will focus on complementary information accessible with X-rays or neutrons, ranging from insights on the structure and colloidal processes at a nanoscale level (SAXS) to details on the lipid organization and molecular interactions of LNPs (SANS). In addition, we will review new opportunities offered by Time-resolved (TR)-SAXS and -SANS for the investigation of dynamic processes involving LNPs. These span from real-time monitoring of LNPs structural evolution in response to endogenous or external stimuli (TR-SANS), to the investigation of the kinetics of lipid diffusion and exchange upon interaction with biomolecules (TR-SANS). Finally, we will spotlight novel combinations of SAXS and SANS with complementary on-line techniques, recently enabled at Large Scale Facilities for X-rays and neutrons. This emerging technology enables synchronized multi-method investigation, offering exciting opportunities for the simultaneous characterization of the structure and chemical or mechanical properties of LNPs.
Collapse
Affiliation(s)
- Lucrezia Caselli
- Physical Chemistry 1, University of Lund, S-221 00 Lund, Sweden.
| | - Laura Conti
- Consorzio Sistemi a Grande Interfase, Department of Chemistry, University of Florence, Sesto Fiorentino, Italy
| | - Ilaria De Santis
- Department of Chemistry, University of Florence, Via della Lastruccia 3, Sesto Fiorentino, Florence 50019, Italy
| | - Debora Berti
- Department of Chemistry, University of Florence, Via della Lastruccia 3, Sesto Fiorentino, Florence 50019, Italy; Consorzio Sistemi a Grande Interfase, Department of Chemistry, University of Florence, Sesto Fiorentino, Italy.
| |
Collapse
|
3
|
Heller WT. Small-Angle Neutron Scattering for Studying Lipid Bilayer Membranes. Biomolecules 2022; 12:1591. [PMID: 36358941 PMCID: PMC9687511 DOI: 10.3390/biom12111591] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 10/18/2022] [Accepted: 10/26/2022] [Indexed: 09/23/2023] Open
Abstract
Small-angle neutron scattering (SANS) is a powerful tool for studying biological membranes and model lipid bilayer membranes. The length scales probed by SANS, being from 1 nm to over 100 nm, are well-matched to the relevant length scales of the bilayer, particularly when it is in the form of a vesicle. However, it is the ability of SANS to differentiate between isotopes of hydrogen as well as the availability of deuterium labeled lipids that truly enable SANS to reveal details of membranes that are not accessible with the use of other techniques, such as small-angle X-ray scattering. In this work, an overview of the use of SANS for studying unilamellar lipid bilayer vesicles is presented. The technique is briefly presented, and the power of selective deuteration and contrast variation methods is discussed. Approaches to modeling SANS data from unilamellar lipid bilayer vesicles are presented. Finally, recent examples are discussed. While the emphasis is on studies of unilamellar vesicles, examples of the use of SANS to study intact cells are also presented.
Collapse
Affiliation(s)
- William T Heller
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| |
Collapse
|
4
|
Perez-Salas U, Porcar L, Garg S, Ayee MAA, Levitan I. Effective Parameters Controlling Sterol Transfer: A Time-Resolved Small-Angle Neutron Scattering Study. J Membr Biol 2022; 255:423-435. [PMID: 35467109 DOI: 10.1007/s00232-022-00231-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2021] [Accepted: 03/19/2022] [Indexed: 11/29/2022]
Abstract
Though cholesterol is the most prevalent and essential sterol in mammalian cellular membranes, its precursors, post-synthesis cholesterol products, as well as its oxidized derivatives play many other important physiological roles. Using a non-invasive in situ technique, time-resolved small angle neutron scattering, we report on the rate of membrane desorption and corresponding activation energy for this process for a series of sterol precursors and post-synthesis cholesterol products that vary from cholesterol by the number and position of double bonds in B ring of cholesterol's steroid core. In addition, we report on sterols that have oxidation modifications in ring A and ring B of the steroid core. We find that sterols that differ in position or the number of double bonds in ring B have similar time and energy characteristics, while oxysterols have faster transfer rates and lower activation energies than cholesterol in a manner generally consistent with known sterol characteristics, like Log P, the n-octanol/water partitioning coefficient. We find, however, that membrane/water partitioning which is dependent on lipid-sterol interactions is a better predictor, shown by the correlation of the sterols' tilt modulus with both the desorption rates and activation energy.
Collapse
Affiliation(s)
- Ursula Perez-Salas
- Physics Department, University of Illinois at Chicago, Chicago, IL, 60607, USA.
| | - Lionel Porcar
- Institut Laue Langevin, 71 Avenue des Martyrs, 38042, Grenoble Cedex 9, France
| | - Sumit Garg
- Physics Department, University of Illinois at Chicago, Chicago, IL, 60607, USA
| | - Manuela A A Ayee
- Department of Engineering, Dordt University, Sioux Center, IA, USA
| | - Irena Levitan
- Division of Pulmonary, Critical Care, Sleep and Allergy, Department of Medicine, University of Illinois at Chicago, Chicago, IL, 60607, USA
| |
Collapse
|
5
|
Himbert S, Rheinstädter MC. Structural and mechanical properties of the red blood cell’s cytoplasmic membrane seen through the lens of biophysics. Front Physiol 2022; 13:953257. [PMID: 36171967 PMCID: PMC9510598 DOI: 10.3389/fphys.2022.953257] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 08/15/2022] [Indexed: 11/27/2022] Open
Abstract
Red blood cells (RBCs) are the most abundant cell type in the human body and critical suppliers of oxygen. The cells are characterized by a simple structure with no internal organelles. Their two-layered outer shell is composed of a cytoplasmic membrane (RBCcm) tethered to a spectrin cytoskeleton allowing the cell to be both flexible yet resistant against shear stress. These mechanical properties are intrinsically linked to the molecular composition and organization of their shell. The cytoplasmic membrane is expected to dominate the elastic behavior on small, nanometer length scales, which are most relevant for cellular processes that take place between the fibrils of the cytoskeleton. Several pathologies have been linked to structural and compositional changes within the RBCcm and the cell’s mechanical properties. We review current findings in terms of RBC lipidomics, lipid organization and elastic properties with a focus on biophysical techniques, such as X-ray and neutron scattering, and Molecular Dynamics simulations, and their biological relevance. In our current understanding, the RBCcm’s structure is patchy, with nanometer sized liquid ordered and disordered lipid, and peptide domains. At the same time, it is surprisingly soft, with bending rigidities κ of 2–4 kBT. This is in strong contrast to the current belief that a high concentration of cholesterol results in stiff membranes. This extreme softness is likely the result of an interaction between polyunsaturated lipids and cholesterol, which may also occur in other biological membranes. There is strong evidence in the literature that there is no length scale dependence of κ of whole RBCs.
Collapse
Affiliation(s)
- Sebastian Himbert
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, Canada
- Origins Institute, McMaster University, Hamilton, ON, Canada
- *Correspondence: Sebastian Himbert, ; Maikel C. Rheinstädter,
| | - Maikel C. Rheinstädter
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, Canada
- Origins Institute, McMaster University, Hamilton, ON, Canada
- *Correspondence: Sebastian Himbert, ; Maikel C. Rheinstädter,
| |
Collapse
|
6
|
Benedetto A, Kelley EG. Absorption of the [bmim][Cl] Ionic Liquid in DMPC Lipid Bilayers across Their Gel, Ripple, and Fluid Phases. J Phys Chem B 2022; 126:3309-3318. [PMID: 35472281 PMCID: PMC9082605 DOI: 10.1021/acs.jpcb.2c00710] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
![]()
Lipid bilayers are
a key component of cell membranes and play a
crucial role in life and in bio-nanotechnology. As a result, controlling
their physicochemical properties holds the promise of effective therapeutic
strategies. Ionic liquids (ILs)—a vast class of complex organic
electrolytes—have shown a high degree of affinity with lipid
bilayers and can be exploited in this context. However, the chemical
physics of IL absorption and partitioning into lipid bilayers is yet
to be fully understood. This work focuses on the absorption of the
model IL [bmim][Cl] into 1,2-dimyristoyl-sn-glycero-3-phosphocholine
(DMPC) lipid bilayers across their gel, ripple, and fluid phases.
Here, by small-angle neutron scattering, we show that (i) the IL cations
are absorbed in the lipid bilayer in all its thermodynamic phases
and (ii) the amount of IL inserted into the lipid phase increased
with increasing temperature, changing from three to four IL cations
per 10 lipids with increasing temperature from 10 °C in the gel
phase to 40 °C in the liquid phase, respectively. An explicative
hypothesis, based on the entropy gain coming from the IL hydration
water, is presented to explain the observed temperature trend. The
ability to control IL absorption with temperature can be used as a
handle to tune the effect of ILs on biomembranes and can be exploited
in bio-nanotechnological applications.
Collapse
Affiliation(s)
- Antonio Benedetto
- Department of Science, University of Roma Tre, 00146 Rome, Italy.,School of Physics, and Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Dublin 4, Ireland.,Laboratory for Neutron Scattering, Paul Scherrer Institute, 5232 Villigen, Switzerland
| | - Elizabeth G Kelley
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
| |
Collapse
|
7
|
Nielsen J, Lund R. Molecular Transport and Growth of Lipid Vesicles Exposed to Antimicrobial Peptides. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:374-384. [PMID: 34902242 PMCID: PMC8757467 DOI: 10.1021/acs.langmuir.1c02736] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 12/01/2021] [Indexed: 05/20/2023]
Abstract
It is well-known that lipids constituting the cytoplasmic membrane undergo continuous reorganization to maintain the appropriate composition important for the integrity of the cell. The transport of lipids is controlled by mainly membrane proteins, but also spontaneous lipid transport between leaflets, lipid "flip-flop", occurs. These processes do not only occur spontaneously under equilibrium, but also promote structural rearrangements, morphological transitions, and growth processes. It has previously been shown that intravesicular lipid "flip-flop" and intervesicular lipid exchange under equilibrium can be deduced indirectly from contrast variation time-resolved small-angle neutron scattering (TR-SANS) where the molecules are "tagged" using hydrogen/deuterium (H/D) substitution. In this work, we show that this technique can be extended to simultaneously detect changes in the growth and the lipid "flip-flop" and exchange rates induced by a peptide additive on lipid vesicles consisting of DMPC (1,2-dimyristoyl-sn-glycero-3-phosphocholine), d-DMPC (1,2-dimyristoyl-d54-sn-glycero-3-phosphocholine), DMPG (1,2-dimyristoyl-sn-glycero-3-phospho-(1'-rac-glycerol)), and small amounts of DMPE-PEG (1,2-dimyristoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000]). Changes in the overall size were independently monitored using dynamic light scattering (DLS). We find that the antimicrobial peptide, indolicidin, accelerates lipid transport and additionally induces limited vesicular growth. Moreover, in TR-SANS experiments using partially labeled lipid mixtures to separately study the kinetics of the lipid components, we show that, whereas peptide addition affects both lipids similarly, DMPG exhibits faster kinetics. We find that vesicular growth is mainly associated with peptide-mediated lipid reorganization that only slightly affects the overall exchange kinetics. This is confirmed by a TR-SANS experiment of vesicles preincubated with peptide showing that after pre-equilibration the kinetics are only slightly slower.
Collapse
Affiliation(s)
| | - Reidar Lund
- Department of Chemistry, University of Oslo, Postboks 1033 Blindern, Oslo 0315, Norway
| |
Collapse
|
8
|
Nguyen MHL, DiPasquale M, Castillo SR, Marquardt D. Time-Resolved SANS to Measure Monomer Inter-Bilayer Exchange and Intra-Bilayer Translocation. Methods Mol Biol 2022; 2402:151-161. [PMID: 34854043 DOI: 10.1007/978-1-0716-1843-1_13] [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] [Indexed: 06/13/2023]
Abstract
The monomeric exchange kinetics of sub-micron particles provide insight into their stability and dynamism. Traditional techniques used to measure the intra- and inter-particle exchange often require monitoring the transfer of bulky and perturbing fluorescent labels. Time-resolved small angle neutron scattering (TR-SANS) overcomes these flaws by isotope labeling, allowing for the monomeric exchange rate determination of unperturbed, stress-free particles. Here, we describe TR-SANS in detail and novel applications of the technique.
Collapse
Affiliation(s)
- Michael H L Nguyen
- Department of Chemistry & Biochemistry, University of Windsor, Windsor, ON, Canada
| | - Mitchell DiPasquale
- Department of Chemistry & Biochemistry, University of Windsor, Windsor, ON, Canada
| | - Stuart R Castillo
- Department of Chemistry & Biochemistry, University of Windsor, Windsor, ON, Canada
| | - Drew Marquardt
- Department of Chemistry & Biochemistry, University of Windsor, Windsor, ON, Canada.
| |
Collapse
|
9
|
Wood K. Small-Angle Neutron Scattering of Liposomes: Sample Preparation to Simple Modeling. Methods Mol Biol 2022; 2402:143-149. [PMID: 34854042 DOI: 10.1007/978-1-0716-1843-1_12] [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] [Indexed: 06/13/2023]
Abstract
Small-angle scattering (SAS) is a technique commonly used in the soft matter sciences to characterize the structure of molecules self-assembling in solution. As such, it is suitable to study preparations of homogeneous liposomes to extract simple structural parameters such as radius and lipid bilayer thickness in solution. Here, we describe the preparation of liposomes for small-angle neutron scattering via extrusion and present the simplest way the resulting data can be modeled.
Collapse
Affiliation(s)
- Kathleen Wood
- Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee, NSW, Australia.
| |
Collapse
|
10
|
Perez-Salas U, Garg S, Gerelli Y, Porcar L. Deciphering lipid transfer between and within membranes with time-resolved small-angle neutron scattering. CURRENT TOPICS IN MEMBRANES 2021; 88:359-412. [PMID: 34862031 DOI: 10.1016/bs.ctm.2021.10.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
This review focuses on time-resolved neutron scattering, particularly time-resolved small angle neutron scattering (TR-SANS), as a powerful in situ noninvasive technique to investigate intra- and intermembrane transport and distribution of lipids and sterols in lipid membranes. In contrast to using molecular analogues with potentially large chemical tags that can significantly alter transport properties, small angle neutron scattering relies on the relative amounts of the two most abundant isotope forms of hydrogen: protium and deuterium to detect complex membrane architectures and transport processes unambiguously. This review discusses advances in our understanding of the mechanisms that sustain lipid asymmetry in membranes-a key feature of the plasma membrane of cells-as well as the transport of lipids between membranes, which is an essential metabolic process.
Collapse
Affiliation(s)
- Ursula Perez-Salas
- Physics Department, University of Illinois at Chicago, Chicago, IL, United States.
| | - Sumit Garg
- Physics Department, University of Illinois at Chicago, Chicago, IL, United States
| | - Yuri Gerelli
- Department of Life and Environmental Sciences, Universita` Politecnica delle Marche, Ancona, Italy
| | | |
Collapse
|
11
|
Preparation of a Deuterated Membrane Protein for Small-Angle Neutron Scattering. Methods Mol Biol 2021. [PMID: 33877630 DOI: 10.1007/978-1-0716-1394-8_12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
This chapter outlines a protocol developed to prepare a purified deuterated membrane protein for a small-angle neutron scattering (SANS) experiment. SANS is a noninvasive technique well suited to studying membrane protein solution structures, and deuteration enhances the signal from the protein over the background (Breyton et al., Eur Phys J E Soft Matter 36 (7):71, 2013; Garg et al., Biophys J 101 (2):370-377, 2011). We present our workflow: transformation of our plasmid into E. coli, cell growth and expression of our deuterated protein, membrane isolation, detergent solubilization, protein purification, purity assessment, and final preparation for SANS.
Collapse
|
12
|
Wilson KA, Fairweather SJ, MacDermott-Opeskin HI, Wang L, Morris RA, O'Mara ML. The role of plasmalogens, Forssman lipids, and sphingolipid hydroxylation in modulating the biophysical properties of the epithelial plasma membrane. J Chem Phys 2021; 154:095101. [PMID: 33685172 DOI: 10.1063/5.0040887] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
A coarse-grain model of the epithelial plasma membrane was developed from high-resolution lipidomic data and simulated using the MARTINI force field to characterize its biophysical properties. Plasmalogen lipids, Forssman glycosphingolipids, and hydroxylated Forssman glycosphingolipids and sphingomyelin were systematically added to determine their structural effects. Plasmalogen lipids have a minimal effect on the overall biophysical properties of the epithelial plasma membrane. In line with the hypothesized role of Forssman lipids in the epithelial apical membrane, the introduction of Forssman lipids initiates the formation of glycosphingolipid-rich nanoscale lipid domains, which also include phosphatidylethanolamine (PE), sphingomyelin (SM), and cholesterol (CHOL). This decreases the lateral diffusion in the extracellular leaflet, as well as the area per lipid of domain forming lipids, most notably PE. Finally, hydroxylation of the Forssman glycosphingolipids and sphingomyelin further modulates the lateral organization of the membrane. Through comparison to the previously studied average and neuronal plasma membranes, the impact of membrane lipid composition on membrane properties was characterized. Overall, this study furthers our understanding of the biophysical properties of complex membranes and the impact of lipid diversity in modulating membrane properties.
Collapse
Affiliation(s)
- Katie A Wilson
- Research School of Chemistry, College of Science, The Australian National University, Canberra, ACT 2601, Australia
| | - Stephen J Fairweather
- Research School of Chemistry, College of Science, The Australian National University, Canberra, ACT 2601, Australia
| | - Hugo I MacDermott-Opeskin
- Research School of Chemistry, College of Science, The Australian National University, Canberra, ACT 2601, Australia
| | - Lily Wang
- Research School of Chemistry, College of Science, The Australian National University, Canberra, ACT 2601, Australia
| | - Richard A Morris
- Research School of Chemistry, College of Science, The Australian National University, Canberra, ACT 2601, Australia
| | - Megan L O'Mara
- Research School of Chemistry, College of Science, The Australian National University, Canberra, ACT 2601, Australia
| |
Collapse
|
13
|
Buwaneka P, Ralko A, Liu SL, Cho W. Evaluation of the available cholesterol concentration in the inner leaflet of the plasma membrane of mammalian cells. J Lipid Res 2021; 62:100084. [PMID: 33964305 PMCID: PMC8178126 DOI: 10.1016/j.jlr.2021.100084] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 04/21/2021] [Accepted: 04/27/2021] [Indexed: 12/11/2022] Open
Abstract
Cholesterol is an essential component of the mammalian plasma membrane involved in diverse cellular processes. Our recent quantitative imaging analysis using ratiometric cholesterol sensors showed that the available cholesterol concentration in the inner leaflet of the plasma membrane (IPM) is low in unstimulated cells and increased in a stimulus-specific manner to trigger cell signaling events. However, the transbilayer distribution of cholesterol in the plasma membrane of mammalian cells remains controversial. Here we report a systematic and rigorous evaluation of basal IPM cholesterol levels in a wide range of mammalian cells with different properties employing cholesterol sensors derived from the D4 domain of the Perfringolysin O toxin and a sterol-transfer protein, Osh4. Results consistently showed that, although basal IPM cholesterol levels vary significantly among cells, they remain significantly lower than cholesterol levels in the outer leaflets. We found that IPM cholesterol levels were particularly low in all tested primary cells. These results support the universality of the low basal IPM cholesterol concentration under physiological conditions. We also report here the presence of sequestered IPM cholesterol pools, which may become available to cytosolic proteins under certain physiological conditions. We hypothesize that these pools may partly account for the low basal level of available IPM cholesterol. In conclusion, we provide new experimental data that confirm the asymmetric transbilayer distribution of the plasma membrane cholesterol, which may contribute to regulation of various cellular signaling processes at the plasma membrane.
Collapse
Affiliation(s)
- Pawanthi Buwaneka
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL, USA
| | - Arthur Ralko
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL, USA
| | - Shu-Lin Liu
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL, USA
| | - Wonhwa Cho
- Department of Chemistry, University of Illinois at Chicago, Chicago, IL, USA.
| |
Collapse
|
14
|
Kinnun JJ, Scott HL, Ashkar R, Katsaras J. Biomembrane Structure and Material Properties Studied With Neutron Scattering. Front Chem 2021; 9:642851. [PMID: 33987167 PMCID: PMC8110834 DOI: 10.3389/fchem.2021.642851] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 03/16/2021] [Indexed: 12/12/2022] Open
Abstract
Cell membranes and their associated structures are dynamical supramolecular structures where different physiological processes take place. Detailed knowledge of their static and dynamic structures is therefore needed, to better understand membrane biology. The structure–function relationship is a basic tenet in biology and has been pursued using a range of different experimental approaches. In this review, we will discuss one approach, namely the use of neutron scattering techniques as applied, primarily, to model membrane systems composed of lipid bilayers. An advantage of neutron scattering, compared to other scattering techniques, is the differential sensitivity of neutrons to isotopes of hydrogen and, as a result, the relative ease of altering sample contrast by substituting protium for deuterium. This property makes neutrons an ideal probe for the study of hydrogen-rich materials, such as biomembranes. In this review article, we describe isotopic labeling studies of model and viable membranes, and discuss novel applications of neutron contrast variation in order to gain unique insights into the structure, dynamics, and molecular interactions of biological membranes. We specifically focus on how small-angle neutron scattering data is modeled using different contrast data and molecular dynamics simulations. We also briefly discuss neutron reflectometry and present a few recent advances that have taken place in neutron spin echo spectroscopy studies and the unique membrane mechanical data that can be derived from them, primarily due to new models used to fit the data.
Collapse
Affiliation(s)
- Jacob J Kinnun
- Large Scale Structures Group, Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States.,Oak Ridge National Laboratory, Shull-Wollan Center, Oak Ridge, TN, United States
| | - Haden L Scott
- Large Scale Structures Group, Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States.,Oak Ridge National Laboratory, Shull-Wollan Center, Oak Ridge, TN, United States
| | - Rana Ashkar
- Department of Physics, Virginia Tech, Blacksburg, VA, United States.,Center for Soft Matter and Biological Physics, Virginia Tech, Blacksburg, VA, United States
| | - John Katsaras
- Oak Ridge National Laboratory, Shull-Wollan Center, Oak Ridge, TN, United States.,Sample Environment Group, Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN, United States.,Department of Physics and Astronomy, University of Tennessee, Knoxville, TN, United States
| |
Collapse
|
15
|
Aghaaminiha M, Farnoud AM, Sharma S. Quantitative relationship between cholesterol distribution and ordering of lipids in asymmetric lipid bilayers. SOFT MATTER 2021; 17:2742-2752. [PMID: 33533367 DOI: 10.1039/d0sm01709d] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The plasma membrane of eukaryotic cells is known to be compositionally asymmetric. Certain phospholipids, such as sphingomyelin and phosphatidylcholine species, are predominantly localized in the outer leaflet, while phosphatidylethanolamine and phosphatidylserine species primarily reside in the inner leaflet. While phospholipid asymmetry between the membrane leaflets is well established, there is no consensus about cholesterol distribution between the two leaflets. We have performed a systematic study, via molecular simulations, of how the spatial distribution of cholesterol molecules in different "asymmetric" lipid bilayers are affected by the lipids' backbone, head-type, unsaturation, and chain-length by considering an asymmetric bilayer mimicking the plasma membrane lipids of red blood cells, as well as seventeen other asymmetric bilayers comprising of different lipid types. Our results reveal that the distribution of cholesterol in the leaflets is solely a function of the extent of ordering of the lipids within the leaflets. The ratio of the amount of cholesterol matches the ratio of lipid order in the two leaflets, thus providing a quantitative relationship between the two. These results are understood by the observation that asymmetric bilayers with equimolar amount of lipids in the two leaflets develop tensile and compressive stresses due to differences in the extent of lipid order. These stresses are alleviated by the transfer of cholesterol from the leaflet in compressive stress to the one in tensile stress. These findings are important in understanding the biology of the cell membrane, especially with regard to the composition of the membrane leaflets.
Collapse
Affiliation(s)
- Mohammadreza Aghaaminiha
- Department of Chemical and Biomolecular Engineering, Russ College of Engineering and Technology, Ohio University, Athens, OH 45701, USA.
| | - Amir M Farnoud
- Department of Chemical and Biomolecular Engineering, Russ College of Engineering and Technology, Ohio University, Athens, OH 45701, USA.
| | - Sumit Sharma
- Department of Chemical and Biomolecular Engineering, Russ College of Engineering and Technology, Ohio University, Athens, OH 45701, USA.
| |
Collapse
|
16
|
Nielsen JE, Bjørnestad VA, Pipich V, Jenssen H, Lund R. Beyond structural models for the mode of action: How natural antimicrobial peptides affect lipid transport. J Colloid Interface Sci 2021; 582:793-802. [DOI: 10.1016/j.jcis.2020.08.094] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 08/21/2020] [Accepted: 08/25/2020] [Indexed: 12/18/2022]
|
17
|
The Antifungal Mechanism of Amphotericin B Elucidated in Ergosterol and Cholesterol-Containing Membranes Using Neutron Reflectometry. NANOMATERIALS 2020; 10:nano10122439. [PMID: 33291326 PMCID: PMC7762259 DOI: 10.3390/nano10122439] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Revised: 12/03/2020] [Accepted: 12/04/2020] [Indexed: 12/25/2022]
Abstract
We have characterized and compared the structures of ergosterol- and cholesterol-containing 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) membranes before and after interaction with the amphiphilic antifungal drug amphotericin B (AmB) using neutron reflection. AmB inserts into both pure POPC and sterol-containing membranes in the lipid chain region and does not significantly perturb the structure of pure POPC membranes. By selective per-deuteration of the lipids/sterols, we show that AmB extracts ergosterol but not cholesterol from the bilayers and inserts to a much higher degree in the cholesterol-containing membranes. Ergosterol extraction by AmB is accompanied by membrane thinning. Our results provide new insights into the mechanism and antifungal effect of AmB in these simple models of fungal and mammalian membranes and help understand the molecular origin of its selectivity and toxic side effects.
Collapse
|
18
|
Composition dependence of cholesterol flip-flop rates in physiological mixtures. Chem Phys Lipids 2020; 232:104967. [PMID: 32888914 DOI: 10.1016/j.chemphyslip.2020.104967] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 08/21/2020] [Accepted: 08/28/2020] [Indexed: 01/06/2023]
Abstract
Unbiased, all-atom simulations of mixtures representative of the inner and outer leaflets of a mammalian red blood cell and a synaptic vesicle reveal many cholesterol flip-flop events over the 5 μsec duration of the simulations. Enough events are observed for a direct estimate of the flip-flop rate. Slower rates are found in more ordered membranes, and faster rates in more disordered membranes, consistent with earlier reports in the literature. However, the rates found here are neither as fast as the fastest nor as slow as the slowest rates obtained by previous simulations. The difference likely stems from the compositions studied here, which unlike previous work include exclusively lipids with differing acyl chains, as observed in mammalian lipidomes.
Collapse
|
19
|
Porcar L, Gerelli Y. On the lipid flip-flop and phase transition coupling. SOFT MATTER 2020; 16:7696-7703. [PMID: 32789357 DOI: 10.1039/d0sm01161d] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
We measured the passive lipid flip-flop of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) in solid supported lipid bilayers across their main gel to fluid (Lβ → Lα) phase transition. By performing time and temperature resolved neutron reflectometry experiments, we demonstrated that asymmetric systems prepared in the gel phase are stable for at least 24 hours. Lipid flip-flop was found to be intrinsically linked to the amount of lipid molecules in the fluid phase. Moreover, the increase of this amount during the broad phase transition was found to be the main key factor for the timing of the flip-flop process. By measuring different temperature scan rate, we could demonstrate that, in the case of supported bilayers and for the temperature investigated, the lipid flip flop is characterised by an activation energy of 50 kJ mol-1 and a timescale on the order of few hours. Our results demonstrate the origin on the discrepancies between passive flip-flop in bulk systems and at interfaces.
Collapse
Affiliation(s)
- Lionel Porcar
- Institut Laue-Langevin, avenue des Martyrs, 38000 Grenoble, France
| | - Yuri Gerelli
- Department of Life and Environmental Sciences, Università Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona, Italy.
| |
Collapse
|
20
|
Liu K, Huang S, Fang D. Electrochemical Measurement of Cholesterol Flip-Flop in Plasma Membrane at Single Cells. Anal Chem 2020; 92:10961-10965. [PMID: 32672037 DOI: 10.1021/acs.analchem.0c01991] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Here, a microelectrode approach is established to measure the flip-flop rate of cholesterol in plasma membranes at single living cells. The initial validation is performed in a modeled phospholipid bilayer positioned at an interconnecting hole between two compartments, in which cholesterol in one compartment diffuses into the other one through a flip-flop movement in the bilayer and is then detected by a cholesterol oxidase-modified microelectrode. As compared with the time (140 ± 28 s) for free cholesterol transport in absence of the bilayer, a prolonged time (702 ± 42 s) is needed to observe the current increase in the presence of the bilayer. The difference in the time (562 s) gives the estimated flip-flop time of cholesterol in the bilayer. The position of the microelectrode in contact with a living cell and the injection of cholesterol inside the cell are further applied to measure the cholesterol flip-flop in the plasma membrane. The average time (1183 ± 146 s) is obtained to observe an additional current increase at the microelectrode, which reflects the cholesterol flip-flop rate in plasma membranes in single living cells. All these results support the establishment of this microelectrode approach for the study of the cholesterol flip-flop process in lipid membranes.
Collapse
Affiliation(s)
- Kang Liu
- School of Pharmacy and Key Laboratory of Targeted Intervention of Cardiovascular Disease, Collaborative Innovation Center for Cardiovascular Disease Translational Medicine, Nanjing Medical University, Nanjing, Jiangsu 211126, China
| | - Shuohan Huang
- School of Pharmacy and Key Laboratory of Targeted Intervention of Cardiovascular Disease, Collaborative Innovation Center for Cardiovascular Disease Translational Medicine, Nanjing Medical University, Nanjing, Jiangsu 211126, China.,Department of Pharmacy, Fudan University Shanghai Cancer Center, 270 Dong'an Road, Shanghai 200032, China
| | | |
Collapse
|
21
|
Lyman E, Sodt AJ. Differential or Curvature Stress? Modus Vivendi. Biophys J 2019; 118:535-537. [PMID: 32023440 DOI: 10.1016/j.bpj.2019.11.3399] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 11/25/2019] [Indexed: 11/15/2022] Open
Affiliation(s)
- Edward Lyman
- Departments of Physics and Astronomy and Chemistry and Biochemistry, University of Delaware, Newark, Delaware.
| | - Alexander J Sodt
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland
| |
Collapse
|
22
|
Nguyen MHL, DiPasquale M, Rickeard BW, Doktorova M, Heberle FA, Scott HL, Barrera FN, Taylor G, Collier CP, Stanley CB, Katsaras J, Marquardt D. Peptide-Induced Lipid Flip-Flop in Asymmetric Liposomes Measured by Small Angle Neutron Scattering. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:11735-11744. [PMID: 31408345 PMCID: PMC7393738 DOI: 10.1021/acs.langmuir.9b01625] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Despite the prevalence of lipid transbilayer asymmetry in natural plasma membranes, most biomimetic model membranes studied are symmetric. Recent advances have helped to overcome the difficulties in preparing asymmetric liposomes in vitro, allowing for the examination of a larger set of relevant biophysical questions. Here, we investigate the stability of asymmetric bilayers by measuring lipid flip-flop with time-resolved small-angle neutron scattering (SANS). Asymmetric large unilamellar vesicles with inner bilayer leaflets containing predominantly 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and outer leaflets composed mainly of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) displayed slow spontaneous flip-flop at 37 ◦C (half-time, t1/2 = 140 h). However, inclusion of peptides, namely, gramicidin, alamethicin, melittin, or pHLIP (i.e., pH-low insertion peptide), accelerated lipid flip-flop. For three of these peptides (i.e., pHLIP, alamethicin, and melittin), each of which was added externally to preformed asymmetric vesicles, we observed a completely scrambled bilayer in less than 2 h. Gramicidin, on the other hand, was preincorporated during the formation of the asymmetric liposomes and showed a time resolvable 8-fold increase in the rate of lipid asymmetry loss. These results point to a membrane surface-related (e.g., adsorption/insertion) event as the primary driver of lipid scrambling in the asymmetric model membranes of this study. We discuss the implications of membrane peptide binding, conformation, and insertion on lipid asymmetry.
Collapse
Affiliation(s)
- Michael H. L. Nguyen
- Department of Chemistry and Biochemistry, University
of Windsor, Windsor, N9B 3P4 ON Canada
| | - Mitchell DiPasquale
- Department of Chemistry and Biochemistry, University
of Windsor, Windsor, N9B 3P4 ON Canada
| | - Brett W. Rickeard
- Department of Chemistry and Biochemistry, University
of Windsor, Windsor, N9B 3P4 ON Canada
| | - Milka Doktorova
- Department of Integrative Biology and Pharmacology,
University of Texas Health Science Center at Houston, Houston, Texas 77225, United
States
| | - Frederick A. Heberle
- Department of Integrative Biology and Pharmacology,
University of Texas Health Science Center at Houston, Houston, Texas 77225, United
States
- Center for Environmental Biotechnology, University
of Tennessee, Knoxville, Tennessee 37996, United States
| | - Haden L. Scott
- Center for Environmental Biotechnology, University
of Tennessee, Knoxville, Tennessee 37996, United States
- Department of Biochemistry & Cellular and
Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996, United
States
| | - Francisco N. Barrera
- Department of Biochemistry & Cellular and
Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996, United
States
| | - Graham Taylor
- The Bredesen Center, University of Tennessee,
Knoxville, Tennessee 37996, United States
| | - Charles P. Collier
- The Bredesen Center, University of Tennessee,
Knoxville, Tennessee 37996, United States
- Center for Nanophase Materials Sciences, Oak Ridge National
Laboratory, Oak Ridge, Tennessee 37831, United States
| | - Christopher B. Stanley
- Neutron Scattering Division, Oak Ridge National
Laboratory, Oak Ridge, Tennessee 37831, United States
| | - John Katsaras
- Large Scale Structures Group, Oak Ridge National
Laboratory, Oak Ridge, Tennessee 37831, United States
- Shull Wollan Center, a Joint Institute for Neutron
Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United
States
- Department of Physics and Astronomy, University of
Tennessee, Knoxville, Tennessee 37996, United States
| | - Drew Marquardt
- Department of Chemistry and Biochemistry, University
of Windsor, Windsor, N9B 3P4 ON Canada
- Department of Physics, University of Windsor, Windsor, N9B
3P4 ON Canada
- Corresponding Author:
| |
Collapse
|
23
|
Garg S, Liu Y, Perez-Salas U, Porcar L, Butler PD. Anomalous inter-membrane cholesterol transport in fluid phase phosphoserine vesicles driven by headgroup ordered to disordered entropic transition. Chem Phys Lipids 2019; 223:104779. [PMID: 31153912 PMCID: PMC11132670 DOI: 10.1016/j.chemphyslip.2019.05.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 05/20/2019] [Indexed: 10/26/2022]
Abstract
POPS is highly enriched in the inner leaflet of the plasma membrane. Here we present measurements of inter-membrane cholesterol transport rates in POPS vesicles. We find that the cholesterol transport kinetics are not only an order of magnitude slower than in POPC lipids at near physiological temperatures, they exhibit a surprising discontinuous Arrhenius behavior around 48 °C. Moreover, thermodynamic analysis suggests that for biologically relevant temperatures, below the discontinuity, the exchange of cholesterol is entropically dominated while it is enthalpically driven, as is the case in POPC vesicles, above that discontinuity. Using the polar fluorescent probe Laurdan we found that POPS fluid membranes retain a large degree of order in the headgroup region for temperatures below the discontinuity but undergo an order-to-disorder transition in the region coinciding with the discontinuity in the transport of cholesterol in POPS membranes providing an explanation not only for the discontinuity but for the entropic dominance at physiological temperatures.
Collapse
Affiliation(s)
- Sumit Garg
- Physics Department, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Yangmingyue Liu
- Physics Department, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Ursula Perez-Salas
- Physics Department, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Lionel Porcar
- Institut Laue Langevin, 71 Avenue des Martyrs, 38042 Grenoble Cedex 9, France
| | - Paul D Butler
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899-6102, USA
| |
Collapse
|
24
|
Shen H, Zhao K, Wu Z. Effects of Ether Linkage on Membrane Dipole Potential and Cholesterol Flip-Flop Motion in Lipid Bilayer Membranes. J Phys Chem B 2019; 123:7818-7828. [DOI: 10.1021/acs.jpcb.9b06570] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Hujun Shen
- Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Guizhou Synergetic Innovation Center of Scientific Big Data for Advanced Manufacturing Technology, Guizhou Education University No.115, Gaoxin Road, Guiyang, Guizhou 550018, P. R. China
- Guizhou University of Finance and Economics, School of Information, University City of Huaxi District, Guiyang, Guizhou 550025, P. R. China
| | - Kun Zhao
- Guizhou University of Finance and Economics, School of Information, University City of Huaxi District, Guiyang, Guizhou 550025, P. R. China
| | - Zhenhua Wu
- Guizhou University of Finance and Economics, School of Information, University City of Huaxi District, Guiyang, Guizhou 550025, P. R. China
| |
Collapse
|
25
|
Shen H, Wu Z, Zhao K, Yang H, Deng M, Wen S. Effect of Cholesterol and 6-Ketocholestanol on Membrane Dipole Potential and Sterol Flip-Flop Motion in Bilayer Membranes. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:11232-11241. [PMID: 31373497 DOI: 10.1021/acs.langmuir.9b01802] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
A variety of experimental and theoretical approaches have been employed to investigate the sterol flip-flop motion in lipid bilayer membranes. However, the sterol effect on the dipole potential of lipid bilayer membranes is less well studied and the influence of dipole potential on sterol flip-flop motion in lipid bilayer membranes is less well understood. In our previous works, we have demonstrated the performance of our coarse-grained (CG) model in the computation of the dipole potential. In this work, five 30 μs CG simulations of dimyristoylphosphatidylcholine (DMPC) bilayers were carried out at different sterol concentrations (in a range from 10 to 50% mole fraction). Then, a comparison was made between the effects of cholesterol (CHOL) and 6-ketocholestanol (6-KC) on the dipole potential of DMPC lipid bilayers as well as the sterol flip-flop motion. Our CG simulations show that the membrane dipole potential is impacted more significantly by 6-KC than by CHOL. This finding is consistent with recent experimental studies. Meanwhile, our work suggests that the sterol-sterol interactions (in particular, electrostatic interactions) should be critical to the formation of sterol-sterol clusters, which would hinder the sterol flip-flop motion inside the lipid bilayers. This is in support of the recent experimental study on the sterol transportation in lipid bilayer membranes.
Collapse
Affiliation(s)
- Hujun Shen
- Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Guizhou Synergetic Innovation Center of Scientific Big Data for Advanced Manufacturing Technology , Guizhou Education University , No. 115, Gaoxin Road , Guiyang , Guizhou 550018 , P. R. China
- School of Information , Guizhou University of Finance and Economics , University City of Huaxi District, Guiyang , Guizhou 550025 , P. R. China
| | - Zhenhua Wu
- School of Information , Guizhou University of Finance and Economics , University City of Huaxi District, Guiyang , Guizhou 550025 , P. R. China
| | - Kun Zhao
- School of Information , Guizhou University of Finance and Economics , University City of Huaxi District, Guiyang , Guizhou 550025 , P. R. China
| | - Hengxiu Yang
- Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Guizhou Synergetic Innovation Center of Scientific Big Data for Advanced Manufacturing Technology , Guizhou Education University , No. 115, Gaoxin Road , Guiyang , Guizhou 550018 , P. R. China
| | - Mingsen Deng
- Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Guizhou Synergetic Innovation Center of Scientific Big Data for Advanced Manufacturing Technology , Guizhou Education University , No. 115, Gaoxin Road , Guiyang , Guizhou 550018 , P. R. China
- School of Information , Guizhou University of Finance and Economics , University City of Huaxi District, Guiyang , Guizhou 550025 , P. R. China
| | - Shuiguo Wen
- Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Guizhou Synergetic Innovation Center of Scientific Big Data for Advanced Manufacturing Technology , Guizhou Education University , No. 115, Gaoxin Road , Guiyang , Guizhou 550018 , P. R. China
| |
Collapse
|
26
|
Enkavi G, Javanainen M, Kulig W, Róg T, Vattulainen I. Multiscale Simulations of Biological Membranes: The Challenge To Understand Biological Phenomena in a Living Substance. Chem Rev 2019; 119:5607-5774. [PMID: 30859819 PMCID: PMC6727218 DOI: 10.1021/acs.chemrev.8b00538] [Citation(s) in RCA: 175] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Indexed: 12/23/2022]
Abstract
Biological membranes are tricky to investigate. They are complex in terms of molecular composition and structure, functional over a wide range of time scales, and characterized by nonequilibrium conditions. Because of all of these features, simulations are a great technique to study biomembrane behavior. A significant part of the functional processes in biological membranes takes place at the molecular level; thus computer simulations are the method of choice to explore how their properties emerge from specific molecular features and how the interplay among the numerous molecules gives rise to function over spatial and time scales larger than the molecular ones. In this review, we focus on this broad theme. We discuss the current state-of-the-art of biomembrane simulations that, until now, have largely focused on a rather narrow picture of the complexity of the membranes. Given this, we also discuss the challenges that we should unravel in the foreseeable future. Numerous features such as the actin-cytoskeleton network, the glycocalyx network, and nonequilibrium transport under ATP-driven conditions have so far received very little attention; however, the potential of simulations to solve them would be exceptionally high. A major milestone for this research would be that one day we could say that computer simulations genuinely research biological membranes, not just lipid bilayers.
Collapse
Affiliation(s)
- Giray Enkavi
- Department
of Physics, University of
Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
| | - Matti Javanainen
- Department
of Physics, University of
Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
- Institute
of Organic Chemistry and Biochemistry of the Czech Academy
of Sciences, Flemingovo naḿesti 542/2, 16610 Prague, Czech Republic
- Computational
Physics Laboratory, Tampere University, P.O. Box 692, FI-33014 Tampere, Finland
| | - Waldemar Kulig
- Department
of Physics, University of
Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
| | - Tomasz Róg
- Department
of Physics, University of
Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
- Computational
Physics Laboratory, Tampere University, P.O. Box 692, FI-33014 Tampere, Finland
| | - Ilpo Vattulainen
- Department
of Physics, University of
Helsinki, P.O. Box 64, FI-00014 Helsinki, Finland
- Computational
Physics Laboratory, Tampere University, P.O. Box 692, FI-33014 Tampere, Finland
- MEMPHYS-Center
for Biomembrane Physics
| |
Collapse
|
27
|
Gu RX, Baoukina S, Tieleman DP. Cholesterol Flip-Flop in Heterogeneous Membranes. J Chem Theory Comput 2019; 15:2064-2070. [PMID: 30633868 DOI: 10.1021/acs.jctc.8b00933] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Cholesterol is the most abundant molecule in the plasma membrane of mammals. Its distribution across the two membrane leaflets is critical for understanding how cells work. Cholesterol trans-bilayer motion (flip-flop) is a key process influencing its distribution in membranes. Despite extensive investigations, the rate of cholesterol flip-flop and its dependence on the lateral heterogeneity of membranes remain uncertain. In this work, we used atomistic molecular dynamics simulations to sample spontaneous cholesterol flip-flop events in a DPPC:DOPC:cholesterol mixture with heterogeneous lateral distribution of lipids. In addition to an overall flip-flop rate at the time scale of sub-milliseconds, we identified a significant impact of local environment on flip-flop rate. We discuss the atomistic details of the flip-flop events observed in our simulations.
Collapse
Affiliation(s)
- Ruo-Xu Gu
- Centre for Molecular Simulation and Department of Biological Sciences , University of Calgary , 2500 University Drive, N.W. , Calgary , Alberta T2N 1N4 , Canada
| | - Svetlana Baoukina
- Centre for Molecular Simulation and Department of Biological Sciences , University of Calgary , 2500 University Drive, N.W. , Calgary , Alberta T2N 1N4 , Canada
| | - D Peter Tieleman
- Centre for Molecular Simulation and Department of Biological Sciences , University of Calgary , 2500 University Drive, N.W. , Calgary , Alberta T2N 1N4 , Canada
| |
Collapse
|
28
|
Bryant G, Taylor MB, Darwish TA, Krause-Heuer AM, Kent B, Garvey CJ. Effect of deuteration on the phase behaviour and structure of lamellar phases of phosphatidylcholines - Deuterated lipids as proxies for the physical properties of native bilayers. Colloids Surf B Biointerfaces 2019; 177:196-203. [PMID: 30743066 DOI: 10.1016/j.colsurfb.2019.01.040] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 12/20/2018] [Accepted: 01/19/2019] [Indexed: 12/29/2022]
Abstract
Deuteration of phospholipids is a common practice to elucidate membrane structure, dynamics and function, by providing selective visualisation in neutron scattering, nuclear magnetic resonance and vibrational spectroscopy. It is generally assumed that the properties of the deuterated lipids are identical to those of the protiated lipids, and while a number of papers have compared the properties of different forms, to date this has been no systematic study of the effects over a range of conditions. Here we present a study of the effects of deuteration on the organisation and phase behaviour of four common phospholipids (DSPC, DPPC, DMPC, DOPC), observing the effect of chain deuteration and headgroup deuteration on lipid structure and phase behaviour. For saturated lipids in excess water the gel-fluid phase transition temperature is 4.3 ± 0.1 °C lower for lipids with deuterated chains compared to protiated chains, consistent with previous work. Despite this significant change, well away from the transition structural changes as measured by powder small angle X-ray scattering are small and within errors. To investigate this further, measurements were carried out on oriented multilamellar stacks of DOPC in the fluid phase at reduced hydration. Neutrons are used in conjunction with contrast variation to elucidate the role of the deuteration explicitly. It is found that deuterated chains cause a reduction in the lamellar repeat spacing and bilayer thickness, but deuterated headgroups cause an increase. Consequences for the interpretation of Neutron Scattering data with deuterated lipids are discussed.
Collapse
Affiliation(s)
- Gary Bryant
- Centre for Molecular and Nanoscale Physics, School of Science, RMIT University, Melbourne, Australia.
| | - Matthew B Taylor
- Centre for Molecular and Nanoscale Physics, School of Science, RMIT University, Melbourne, Australia
| | - Tamim A Darwish
- National Deuteration Facility, Australian Nuclear Science and Technology Organisation, Lucas Heights, Australia.
| | - Anwen M Krause-Heuer
- National Deuteration Facility, Australian Nuclear Science and Technology Organisation, Lucas Heights, Australia
| | - Ben Kent
- Institute for Soft Matter and Functional Materials, Helmholtz-Zentrum Berlin, Berlin, Germany.
| | - Christopher J Garvey
- Neutron Scattering, Australian Nuclear Science and Technology Organisation, Lucas Heights, Australia.
| |
Collapse
|
29
|
Nguyen MHL, DiPasquale M, Rickeard BW, Stanley CB, Kelley EG, Marquardt D. Methanol Accelerates DMPC Flip-Flop and Transfer: A SANS Study on Lipid Dynamics. Biophys J 2019; 116:755-759. [PMID: 30777306 DOI: 10.1016/j.bpj.2019.01.021] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 01/17/2019] [Accepted: 01/23/2019] [Indexed: 10/27/2022] Open
Abstract
Methanol is a common solubilizing agent used to study transmembrane proteins/peptides in biological and synthetic membranes. Using small angle neutron scattering and a strategic contrast-matching scheme, we show that methanol has a major impact on lipid dynamics. Under increasing methanol concentrations, isotopically distinct 1,2-dimyristoyl-sn-glycero-3-phosphocholine large unilamellar vesicle populations exhibit increased mixing. Specifically, 1,2-dimyristoyl-sn-glycero-3-phosphocholine transfer and flip-flop kinetics display linear and exponential rate enhancements, respectively. Ultimately, methanol is capable of influencing the structure-function relationship associated with bilayer composition (e.g., lipid asymmetry). The use of methanol as a carrier solvent, despite better simulating some biological conditions (e.g., antimicrobial attack), can help misconstrue lipid scrambling as the action of proteins or peptides, when in actuality it is a combination of solvent and biological agent. As bilayer compositional stability is crucial to cell survival and protein reconstitution, these results highlight the importance of methanol, and solvents in general, in biomembrane and proteolipid studies.
Collapse
Affiliation(s)
- Michael H L Nguyen
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada
| | - Mitchell DiPasquale
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada
| | - Brett W Rickeard
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada
| | | | - Elizabeth G Kelley
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland
| | - Drew Marquardt
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada.
| |
Collapse
|
30
|
Ashkar R, Bilheux HZ, Bordallo H, Briber R, Callaway DJE, Cheng X, Chu XQ, Curtis JE, Dadmun M, Fenimore P, Fushman D, Gabel F, Gupta K, Herberle F, Heinrich F, Hong L, Katsaras J, Kelman Z, Kharlampieva E, Kneller GR, Kovalevsky A, Krueger S, Langan P, Lieberman R, Liu Y, Losche M, Lyman E, Mao Y, Marino J, Mattos C, Meilleur F, Moody P, Nickels JD, O'Dell WB, O'Neill H, Perez-Salas U, Peters J, Petridis L, Sokolov AP, Stanley C, Wagner N, Weinrich M, Weiss K, Wymore T, Zhang Y, Smith JC. Neutron scattering in the biological sciences: progress and prospects. ACTA CRYSTALLOGRAPHICA SECTION D-STRUCTURAL BIOLOGY 2018; 74:1129-1168. [PMID: 30605130 DOI: 10.1107/s2059798318017503] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 12/12/2018] [Indexed: 12/11/2022]
Abstract
The scattering of neutrons can be used to provide information on the structure and dynamics of biological systems on multiple length and time scales. Pursuant to a National Science Foundation-funded workshop in February 2018, recent developments in this field are reviewed here, as well as future prospects that can be expected given recent advances in sources, instrumentation and computational power and methods. Crystallography, solution scattering, dynamics, membranes, labeling and imaging are examined. For the extraction of maximum information, the incorporation of judicious specific deuterium labeling, the integration of several types of experiment, and interpretation using high-performance computer simulation models are often found to be particularly powerful.
Collapse
Affiliation(s)
- Rana Ashkar
- Department of Physics, Virginia Polytechnic Institute and State University, 850 West Campus Drive, Blacksburg, VA 24061, USA
| | - Hassina Z Bilheux
- Neutron Sciences Directorate, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, USA
| | | | - Robert Briber
- Materials Science and Engineeering, University of Maryland, 1109 Chemical and Nuclear Engineering Building, College Park, MD 20742, USA
| | - David J E Callaway
- Department of Chemistry and Biochemistry, The City College of New York, 160 Convent Avenue, New York, NY 10031, USA
| | - Xiaolin Cheng
- Department of Medicinal Chemistry and Pharmacognosy, Ohio State University College of Pharmacy, 642 Riffe Building, Columbus, OH 43210, USA
| | - Xiang Qiang Chu
- Graduate School of China Academy of Engineering Physics, Beijing, 100193, People's Republic of China
| | - Joseph E Curtis
- NIST Center for Neutron Research, National Institutes of Standard and Technology, 100 Bureau Drive, Mail Stop 6102, Gaithersburg, MD 20899, USA
| | - Mark Dadmun
- Department of Chemistry, University of Tennessee Knoxville, Knoxville, TN 37996, USA
| | - Paul Fenimore
- Los Alamos National Laboratory, Los Alamos, NM 87545, USA
| | - David Fushman
- Department of Chemistry and Biochemistry, Center for Biomolecular Structure and Organization, University of Maryland, College Park, MD 20742, USA
| | - Frank Gabel
- Institut Laue-Langevin, Université Grenoble Alpes, CEA, CNRS, IBS, 38042 Grenoble, France
| | - Kushol Gupta
- Department of Biochemistry and Biophysics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Frederick Herberle
- Neutron Sciences Directorate, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, USA
| | - Frank Heinrich
- NIST Center for Neutron Research, National Institutes of Standard and Technology, 100 Bureau Drive, Mail Stop 6102, Gaithersburg, MD 20899, USA
| | - Liang Hong
- Department of Physics and Astronomy, Institute of Natural Sciences, Shanghai Jiao Tong University, Shanghai 200240, People's Republic of China
| | - John Katsaras
- Neutron Scattering Science Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Zvi Kelman
- Institute for Bioscience and Biotechnology Research, National Institute of Standards and Technology and the University of Maryland, Rockville, MD 20850, USA
| | - Eugenia Kharlampieva
- Department of Chemistry, University of Alabama at Birmingham, 901 14th Street South, Birmingham, AL 35294, USA
| | - Gerald R Kneller
- Centre de Biophysique Moléculaire, CNRS, Université d'Orléans, Chateau de la Source, Avenue du Parc Floral, Orléans, France
| | - Andrey Kovalevsky
- Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Susan Krueger
- NIST Center for Neutron Research, National Institutes of Standard and Technology, 100 Bureau Drive, Mail Stop 6102, Gaithersburg, MD 20899, USA
| | - Paul Langan
- Neutron Sciences Directorate, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, USA
| | - Raquel Lieberman
- School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Yun Liu
- NIST Center for Neutron Research, National Institutes of Standard and Technology, 100 Bureau Drive, Mail Stop 6102, Gaithersburg, MD 20899, USA
| | - Mathias Losche
- Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
| | - Edward Lyman
- Department of Physics and Astrophysics, University of Delaware, Newark, DE 19716, USA
| | - Yimin Mao
- NIST Center for Neutron Research, National Institutes of Standard and Technology, 100 Bureau Drive, Mail Stop 6102, Gaithersburg, MD 20899, USA
| | - John Marino
- Institute for Bioscience and Biotechnology Research, National Institute of Standards and Technology and the University of Maryland, Rockville, MD 20850, USA
| | - Carla Mattos
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, Massachusetts, USA
| | - Flora Meilleur
- Neutron Sciences Directorate, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, USA
| | - Peter Moody
- Leicester Institute of Structural and Chemical Biology, Department of Molecular and Cell Biology, University of Leicester, Leicester LE1 9HN, England
| | - Jonathan D Nickels
- Department of Physics, Virginia Polytechnic Institute and State University, 850 West Campus Drive, Blacksburg, VA 24061, USA
| | - William B O'Dell
- Institute for Bioscience and Biotechnology Research, National Institute of Standards and Technology and the University of Maryland, Rockville, MD 20850, USA
| | - Hugh O'Neill
- Neutron Sciences Directorate, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, USA
| | - Ursula Perez-Salas
- Neutron Sciences Directorate, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, USA
| | | | - Loukas Petridis
- Materials Science and Engineeering, University of Maryland, 1109 Chemical and Nuclear Engineering Building, College Park, MD 20742, USA
| | - Alexei P Sokolov
- Department of Chemistry, University of Tennessee Knoxville, Knoxville, TN 37996, USA
| | - Christopher Stanley
- Neutron Sciences Directorate, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, USA
| | - Norman Wagner
- Department of Chemistry and Biochemistry, The City College of New York, 160 Convent Avenue, New York, NY 10031, USA
| | - Michael Weinrich
- NIST Center for Neutron Research, National Institutes of Standard and Technology, 100 Bureau Drive, Mail Stop 6102, Gaithersburg, MD 20899, USA
| | - Kevin Weiss
- Neutron Sciences Directorate, Oak Ridge National Laboratory, 1 Bethel Valley Road, Oak Ridge, TN 37831, USA
| | - Troy Wymore
- Graduate School of China Academy of Engineering Physics, Beijing, 100193, People's Republic of China
| | - Yang Zhang
- NIST Center for Neutron Research, National Institutes of Standard and Technology, 100 Bureau Drive, Mail Stop 6102, Gaithersburg, MD 20899, USA
| | - Jeremy C Smith
- Department of Medicinal Chemistry and Pharmacognosy, Ohio State University College of Pharmacy, 642 Riffe Building, Columbus, OH 43210, USA
| |
Collapse
|
31
|
Seo S, Shinoda W. SPICA Force Field for Lipid Membranes: Domain Formation Induced by Cholesterol. J Chem Theory Comput 2018; 15:762-774. [PMID: 30514078 DOI: 10.1021/acs.jctc.8b00987] [Citation(s) in RCA: 58] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Heterogeneity is essential for multicomponent lipid membranes. Especially, sterol-induced domain formation in membranes has recently attracted attention because of its biological importance. To investigate such membrane domains at the molecular level, coarse-grained molecular dynamics (CG-MD) simulations are a promising approach since they allow one to consider the temporal and spatial scales involved in domain formation. In this work, we present a new CG force field, named SPICA, which can accurately predict domain formation within various lipids in membranes. The SPICA force field was developed as an extension of a previous CG model, known as SDK (Shinoda-DeVane-Klein), in which membrane properties such as tension, elasticity, and structure are well reproduced. By examining domain formation in a series of ternary lipid bilayers, we observed a separation into liquid-ordered and liquid-disordered phases fully consistent with experimental observations. Importantly, it is shown that the SPICA force field can detect the different phase behavior that results from subtle differences in the lipid composition of the bilayer.
Collapse
Affiliation(s)
- Sangjae Seo
- Department of Materials Chemistry , Nagoya University , Furo-cho, Chikusa-ku, Nagoya 464-8603 , Japan
| | - Wataru Shinoda
- Department of Materials Chemistry , Nagoya University , Furo-cho, Chikusa-ku, Nagoya 464-8603 , Japan
| |
Collapse
|
32
|
Steck TL, Lange Y. Transverse distribution of plasma membrane bilayer cholesterol: Picking sides. Traffic 2018; 19:750-760. [PMID: 29896788 DOI: 10.1111/tra.12586] [Citation(s) in RCA: 88] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 06/04/2018] [Accepted: 06/05/2018] [Indexed: 12/23/2022]
Abstract
The transverse asymmetry (sidedness) of phospholipids in plasma membrane bilayers is well characterized, distinctive, actively maintained and functionally important. In contrast, numerous studies using a variety of techniques have concluded that plasma membrane bilayer cholesterol is either mostly in the outer leaflet or the inner leaflet or is fairly evenly distributed. Sterols might simply partition according to their differing affinities for the asymmetrically disposed phospholipids, but some studies have proposed that it is actively transported to the outer leaflet. Other work suggests that the sterol is enriched in the inner leaflet, driven by either positive interactions with the phosphatidylethanolamine on that side or by its exclusion from the outer leaflet by the long chain sphingomyelin molecules therein. This uncertainty raises three questions: is plasma membrane cholesterol sidedness fixed in a given cell or cell type; is it generally the same among mammalian species; and does it serve specific physiological functions? This review grapples with these issues.
Collapse
Affiliation(s)
- Theodore L Steck
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois
| | - Yvonne Lange
- Department of Pathology, Rush University Medical Center, Chicago, Illinois
| |
Collapse
|
33
|
Shen H, Deng M, Wu Z, Zhang J, Zhang Y, Gao C, Cen C. Effect of Cholesterol on Membrane Dipole Potential: Atomistic and Coarse-Grained Molecular Dynamics Simulations. J Chem Theory Comput 2018; 14:3780-3795. [DOI: 10.1021/acs.jctc.8b00092] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Hujun Shen
- Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Guizhou Synergetic Innovation Center of Scientific Big Data for Advanced Manufacturing Technology, Guizhou Education University, No. 115, Gaoxin Road, Guiyang, Guizhou 550018, P. R. China
- Guizhou University of Finance and Economics, School of Information, University City of Huaxi District, Guiyang, Guizhou 550025, P. R. China
| | - Mingsen Deng
- Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Guizhou Synergetic Innovation Center of Scientific Big Data for Advanced Manufacturing Technology, Guizhou Education University, No. 115, Gaoxin Road, Guiyang, Guizhou 550018, P. R. China
- Guizhou University of Finance and Economics, School of Information, University City of Huaxi District, Guiyang, Guizhou 550025, P. R. China
| | - Zhenhua Wu
- Guizhou University of Finance and Economics, School of Information, University City of Huaxi District, Guiyang, Guizhou 550025, P. R. China
| | - Jihua Zhang
- Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Guizhou Synergetic Innovation Center of Scientific Big Data for Advanced Manufacturing Technology, Guizhou Education University, No. 115, Gaoxin Road, Guiyang, Guizhou 550018, P. R. China
| | - Yachao Zhang
- Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Guizhou Synergetic Innovation Center of Scientific Big Data for Advanced Manufacturing Technology, Guizhou Education University, No. 115, Gaoxin Road, Guiyang, Guizhou 550018, P. R. China
| | - Chengui Gao
- Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Guizhou Synergetic Innovation Center of Scientific Big Data for Advanced Manufacturing Technology, Guizhou Education University, No. 115, Gaoxin Road, Guiyang, Guizhou 550018, P. R. China
| | - Cao Cen
- Guizhou Provincial Key Laboratory of Computational Nano-Material Science, Guizhou Synergetic Innovation Center of Scientific Big Data for Advanced Manufacturing Technology, Guizhou Education University, No. 115, Gaoxin Road, Guiyang, Guizhou 550018, P. R. China
| |
Collapse
|
34
|
Schoch RL, Barel I, Brown FLH, Haran G. Lipid diffusion in the distal and proximal leaflets of supported lipid bilayer membranes studied by single particle tracking. J Chem Phys 2018; 148:123333. [DOI: 10.1063/1.5010341] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Affiliation(s)
- Rafael L. Schoch
- Department of Chemical and Biological Physics, Weizmann Institute of Science, P.O. Box 26, Rehovot 7610001, Israel
| | - Itay Barel
- Department of Chemistry and Biochemistry and Department of Physics, University of California, Santa Barbara, Santa Barbara, California 93106, USA
| | - Frank L. H. Brown
- Department of Chemistry and Biochemistry and Department of Physics, University of California, Santa Barbara, Santa Barbara, California 93106, USA
| | - Gilad Haran
- Department of Chemical and Biological Physics, Weizmann Institute of Science, P.O. Box 26, Rehovot 7610001, Israel
| |
Collapse
|
35
|
Schantz AB, Ren T, Pachalla A, Shen Y, Hickey RJ, Kumar M. Porous Vesicles with Extrusion‐Tunable Permeability and Pore Size from Mixed Solutions of PEO–PPO–PEO Triblock Copolymers. MACROMOL CHEM PHYS 2018. [DOI: 10.1002/macp.201700620] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- A. Benjamin Schantz
- Department of Chemical Engineering The Pennsylvania State University 125 Greenberg Complex University Park PA 16802 USA
| | - Tingwei Ren
- Department of Chemical Engineering The Pennsylvania State University 125 Greenberg Complex University Park PA 16802 USA
| | - Abhishek Pachalla
- Department of Chemical Engineering The Pennsylvania State University 125 Greenberg Complex University Park PA 16802 USA
| | - Yuexiao Shen
- Department of Chemical Engineering The Pennsylvania State University 125 Greenberg Complex University Park PA 16802 USA
| | - Robert J. Hickey
- Department of Materials Science and Engineering The Pennsylvania State University 403 Steidle Building University Park PA 16802 USA
| | - Manish Kumar
- Department of Chemical Engineering The Pennsylvania State University 125 Greenberg Complex University Park PA 16802 USA
| |
Collapse
|
36
|
Shaghaghi M, Keyvanloo A, Huang Z, Szoka FC, Thewalt JL. Constrained Versus Free Cholesterol in DPPC Membranes: A Comparison of Chain Ordering Ability Using Deuterium NMR. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:14405-14413. [PMID: 29120186 DOI: 10.1021/acs.langmuir.7b03299] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We report here the first exploration of the nature of the hydrophobic region of bilayer membranes formed from sterol-modified phospholipids [Huang, Z.; Szoka, F. C., Sterol-Modified Phospholipids: Cholesterol and Phospholipid Chimeras with Improved Biomembrane Properties. J. Am. Chem. Soc. 2008, 130 (46), 15702-15712] & [Ding, J.; Starling, A. P.; East, J. M.; Lee, A. G., Binding Sites for Cholesterol on Ca(2+)-ATPase Studied by Using a Cholesterol-Containing Phospholipid. Biochemistry 1994, 33 (16), 4974-4979]. Using 2H NMR spectroscopy, we present our results for the phase behavior and acyl chain ordering of multilamellar vesicles (MLVs) of a sterol-modified phospholipid, 1-cholesterylhemisuccinoyl-2-palmitoyl(d31)-sn-glycero-3-phosphocholine (hereafter referred to as CholPPC-d31). We compared our results with the conformational order induced by cholesterol at various concentrations in 1-palmitoyl,2-palmitoyl(d31)-sn-glycero-3-phosphocholine (DPPC-d31)/cholesterol membranes. On the basis of the existing literature [Foglia, F.; Barlow, D. J.; Szoka, F. C.; Huang, Z.; Rogers, S. E.; Lawrence, M. J., Structural Studies of the Monolayers and Bilayers Formed by a Novel Cholesterol-Phospholipid Chimera. Langmuir 2011, 27 (13), 8275-8281], we expected to find that the deuterated palmitoyl chain in CholPPC-d31 membranes had an order parameter profile similar to the deuterated palmitoyl chain of sn-2 labeled DPPC-d31 in MLVs of a mixture of DPPC-d31 with 40 mol % unconstrained cholesterol. Our data indicate that the ordering ability of cholesterol in CholPPC is significantly reduced compared to free cholesterol in DPPC. This result emphasizes that cholesterol molecules must be free to move in the bilayers to reach their maximum ordering ability. In other words, when compared to unconstrained cholesterol, the constrained cholesterol moiety in CholPPC causes nonoptimal chain packing.
Collapse
Affiliation(s)
| | | | - Zhaohua Huang
- Merrimack Pharmaceuticals , One Kendall Square, Suite B7201, Cambridge, Massachusetts 02139, United States
| | - Francis C Szoka
- Department of Bioengineering and Therapeutic Sciences, School of Pharmacy, University of California , San Francisco, California 94143, United States
| | | |
Collapse
|
37
|
Breidigan JM, Krzyzanowski N, Liu Y, Porcar L, Perez-Salas U. Influence of the membrane environment on cholesterol transfer. J Lipid Res 2017; 58:2255-2263. [PMID: 29046341 PMCID: PMC5711489 DOI: 10.1194/jlr.m077909] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 07/09/2017] [Indexed: 01/28/2023] Open
Abstract
Cholesterol, an essential component in biological membranes, is highly unevenly distributed within the cell, with most localized in the plasma membrane while only a small fraction is found in the endoplasmic reticulum, where it is synthesized. Cellular membranes differ in lipid composition and protein content, and these differences can exist across their leaflets too. This thermodynamic landscape that cellular membranes impose on cholesterol is expected to modulate its transport. To uncover the role the membrane environment has on cholesterol inter- and intra-membrane movement, we used time-resolved small angle neutron scattering to study the passive movement of cholesterol between and within membranes with varying degrees of saturation content. We found that cholesterol moves systematically slower as the degree of saturation in the membranes increases, from a palmitoyl oleyl phosphotidylcholine membrane, which is unsaturated, to a dipalmitoylphosphatidylcholine (DPPC) membrane, which is fully saturated. Additionally, we found that the energetic barrier to move cholesterol in these phosphatidylcholine membranes is independent of their relative lipid composition and remains constant for both flip-flop and exchange at ∼100 kJ/mol. Further, by replacing DPPC with the saturated lipid palmitoylsphingomyelin, an abundant saturated lipid of the outer leaflet of the plasma membrane, we found the rates decreased by a factor of two. This finding is in stark contrast with recent molecular dynamic simulations that predict a dramatic slow-down of seven orders of magnitude for cholesterol flipping in membranes with a similar phosphocholine and SM lipid composition.
Collapse
Affiliation(s)
| | | | - Yangmingyue Liu
- Department of Physics, University of Illinois at Chicago, Chicago, IL 60607
| | - Lionel Porcar
- Large Scale Structures Group, Institut Laue-Langevin, F-38042 Grenoble CEDEX 9, France
| | - Ursula Perez-Salas
- Department of Physics, University of Illinois at Chicago, Chicago, IL 60607
| |
Collapse
|
38
|
Browning KL, Lind TK, Maric S, Malekkhaiat-Häffner S, Fredrikson GN, Bengtsson E, Malmsten M, Cárdenas M. Human Lipoproteins at Model Cell Membranes: Effect of Lipoprotein Class on Lipid Exchange. Sci Rep 2017; 7:7478. [PMID: 28785025 PMCID: PMC5547137 DOI: 10.1038/s41598-017-07505-0] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 06/29/2017] [Indexed: 01/19/2023] Open
Abstract
High and low density lipoproteins (HDL and LDL) are thought to play vital roles in the onset and development of atherosclerosis; the biggest killer in the western world. Key issues of initial lipoprotein (LP) interactions at cellular membranes need to be addressed including LP deposition and lipid exchange. Here we present a protocol for monitoring the in situ kinetics of lipoprotein deposition and lipid exchange/removal at model cellular membranes using the non-invasive, surface sensitive methods of neutron reflection and quartz crystal microbalance with dissipation. For neutron reflection, lipid exchange and lipid removal can be distinguished thanks to the combined use of hydrogenated and tail-deuterated lipids. Both HDL and LDL remove lipids from the bilayer and deposit hydrogenated material into the lipid bilayer, however, the extent of removal and exchange depends on LP type. These results support the notion of HDL acting as the ‘good’ cholesterol, removing lipid material from lipid-loaded cells, whereas LDL acts as the ‘bad’ cholesterol, depositing lipid material into the vascular wall.
Collapse
Affiliation(s)
- K L Browning
- Department of Pharmacy, Uppsala University, Uppsala, Sweden
| | - T K Lind
- Department of Biomedical Sciences and Biofilms, Malmö University, Malmö, Sweden
| | - S Maric
- Department of Biomedical Sciences and Biofilms, Malmö University, Malmö, Sweden
| | | | - G N Fredrikson
- Department of Clinical Sciences, Malmö, Lund University, Malmö, Sweden
| | - E Bengtsson
- Department of Clinical Sciences, Malmö, Lund University, Malmö, Sweden
| | - M Malmsten
- Department of Pharmacy, Uppsala University, Uppsala, Sweden. .,Department of Pharmacy, University of Copenhagen, Copenhagen, Denmark.
| | - M Cárdenas
- Department of Biomedical Sciences and Biofilms, Malmö University, Malmö, Sweden.
| |
Collapse
|
39
|
Wah B, Breidigan JM, Adams J, Horbal P, Garg S, Porcar L, Perez-Salas U. Reconciling Differences between Lipid Transfer in Free-Standing and Solid Supported Membranes: A Time-Resolved Small-Angle Neutron Scattering Study. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:3384-3394. [PMID: 28300412 DOI: 10.1021/acs.langmuir.6b04013] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Maintaining compositional lipid gradients across membranes in animal cells is essential to biological function, but what is the energetic cost to maintain these differences? It has long been recognized that studying the passive movement of lipids in membranes can provide insight into this toll. Confusingly the reported values of inter- and, particularly, intra-lipid transport rates of lipids in membranes show significant differences. To overcome this difficulty, biases introduced by experimental approaches have to be identified. The present study addresses the difference in the reported intramembrane transport rates of dimyristoylphosphatidylcholine (DMPC) on flat solid supports (fast flipping) and in curved free-standing membranes (slow flipping). Two possible scenarios are potentially at play: one is the difference in curvature of the membranes studied and the other the presence (or not) of the support. Using DMPC vesicles and DMPC supported membranes on silica nanoparticles of different radii, we found that an increase in curvature (from a diameter of 30 nm to a diameter of 100 nm) does not change the rates significantly, differing only by factors of order ∼1. Additionally, we found that the exchange rates of DMPC in supported membranes are similar to the ones in vesicles. And as previously reported, we found that the activation energies for exchange on free-standing and supported membranes are similar (84 and 78 kJ/mol, respectively). However, DMPC's flip-flop rates increase significantly when in a supported membrane, surpassing the exchange rates and no longer limiting the exchange process. Although the presence of holes or cracks in supported membranes explains the occurrence of fast lipid flip-flop in many studies, in defect-free supported membranes we find that fast flip-flop is driven by the surface's induced disorder of the bilayer's acyl chain packing as evidenced from their broad melting temperature behavior.
Collapse
Affiliation(s)
- Benny Wah
- Physics Department, University of Illinois at Chicago , Chicago, Illinois 60607, United States
| | - Jeffrey M Breidigan
- Physics Department, University of Illinois at Chicago , Chicago, Illinois 60607, United States
| | - Joseph Adams
- Physics Department, University of Illinois at Chicago , Chicago, Illinois 60607, United States
| | - Piotr Horbal
- Physics Department, University of Illinois at Chicago , Chicago, Illinois 60607, United States
| | - Sumit Garg
- Physics Department, University of Illinois at Chicago , Chicago, Illinois 60607, United States
- Materials Science Division, Argonne National Laboratory , Lemont, Illinois 60439, United States
| | - Lionel Porcar
- Large Scale Structure Group, Institut Laue-Langevin , Grenoble F-38042, France
- Department of Chemical Engineering, Colburn Laboratory, University of Delaware , Newark, Delaware 19716, United States
| | - Ursula Perez-Salas
- Physics Department, University of Illinois at Chicago , Chicago, Illinois 60607, United States
- Materials Science Division, Argonne National Laboratory , Lemont, Illinois 60439, United States
| |
Collapse
|
40
|
Schantz AB, Saboe PO, Sines IT, Lee HY, Bishop KJM, Maranas JK, Butler PD, Kumar M. PEE–PEO Block Copolymer Exchange Rate between Mixed Micelles Is Detergent and Temperature Activated. Macromolecules 2017. [DOI: 10.1021/acs.macromol.6b01973] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Affiliation(s)
- Allen B. Schantz
- Department
of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Patrick O. Saboe
- Department
of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Ian T. Sines
- Department
of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Hee-Young Lee
- Department
of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Kyle J. M. Bishop
- Department
of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Janna K. Maranas
- Department
of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| | - Paul D. Butler
- NIST
Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6102, United States
- Department
of Chemistry, University of Tennessee, Knoxville, Knoxville, Tennessee 37996-1600, United States
| | - Manish Kumar
- Department
of Chemical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
| |
Collapse
|
41
|
Narayanan T, Wacklin H, Konovalov O, Lund R. Recent applications of synchrotron radiation and neutrons in the study of soft matter. CRYSTALLOGR REV 2017. [DOI: 10.1080/0889311x.2016.1277212] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
| | - Hanna Wacklin
- European Spallation Source ERIC, Lund, Sweden
- Physical Chemistry, Lund University, Lund, Sweden
| | | | - Reidar Lund
- Department of Chemistry, University of Oslo, Blindern, Oslo, Norway
| |
Collapse
|
42
|
Yu T, Zhou G, Hu X, Ye S. Transport and Organization of Cholesterol in a Planar Solid-Supported Lipid Bilayer Depend on the Phospholipid Flip-Flop Rate. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:11681-11689. [PMID: 27756133 DOI: 10.1021/acs.langmuir.6b02560] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Understanding the transport behavior of the cholesterol molecules within a cell membrane is a key challenge in cell biology at present. Here, we have applied sum frequency generation vibrational spectroscopy to characterize the transport and organization of cholesterol in different kinds of planar solid-supported lipid bilayers by combining achiral- and chiral-sensitive polarization measurements. This method allows us to distinguish the organization of cholesterol in tail-to-tail, head-to-tail, head-to-head, and side-by-side manners. It is found that the movement of cholesterol in the lipid bilayer largely depends on the flip-flop rate of the phospholipid. The flip-flop dynamics of the phospholipid and cholesterol are synchronous. In the solid-supported zwitterionic phosphocholine lipid bilayer, the cholesterol molecules flip quickly from the distal leaflet to the neutral proximal leaflet of the bilayer and form tail-to-tail organization on both leaflets. The phosphocholine lipid and cholesterol show the same flip-flop rate. However, when the proximal leaflet is prepared using negative glycerol phospholipids, cholesterol organizes itself by mainly forming an α-β structure on the distal leaflet. Because of the strong interaction between the glycerol phospholipid and the substrate, no or only partial cholesterol molecules flip from the distal leaflet to the negatively charged proximal leaflet. However, the cholesterol molecules undergo flip-flop in the presence of salt solution because the ions weaken the interaction between the negative phospholipid and the substrate.
Collapse
Affiliation(s)
- Ting Yu
- Hefei National Laboratory for Physical Sciences at the Microscale, and Department of Chemical Physics and ‡Synergetic Innovation Center of Quantum Information & Quantum Physics, University of Science and Technology of China , Hefei, Anhui 230026, China
| | - Guangnan Zhou
- Hefei National Laboratory for Physical Sciences at the Microscale, and Department of Chemical Physics and ‡Synergetic Innovation Center of Quantum Information & Quantum Physics, University of Science and Technology of China , Hefei, Anhui 230026, China
| | - Xia Hu
- Hefei National Laboratory for Physical Sciences at the Microscale, and Department of Chemical Physics and ‡Synergetic Innovation Center of Quantum Information & Quantum Physics, University of Science and Technology of China , Hefei, Anhui 230026, China
| | - Shuji Ye
- Hefei National Laboratory for Physical Sciences at the Microscale, and Department of Chemical Physics and ‡Synergetic Innovation Center of Quantum Information & Quantum Physics, University of Science and Technology of China , Hefei, Anhui 230026, China
| |
Collapse
|
43
|
Marquardt D, Kučerka N, Wassall SR, Harroun TA, Katsaras J. Cholesterol's location in lipid bilayers. Chem Phys Lipids 2016; 199:17-25. [DOI: 10.1016/j.chemphyslip.2016.04.001] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2016] [Revised: 04/01/2016] [Accepted: 04/02/2016] [Indexed: 02/07/2023]
|
44
|
Egawa J, Pearn ML, Lemkuil BP, Patel PM, Head BP. Membrane lipid rafts and neurobiology: age-related changes in membrane lipids and loss of neuronal function. J Physiol 2016; 594:4565-79. [PMID: 26332795 PMCID: PMC4983616 DOI: 10.1113/jp270590] [Citation(s) in RCA: 114] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2015] [Accepted: 08/13/2015] [Indexed: 12/15/2022] Open
Abstract
A better understanding of the cellular physiological role that plasma membrane lipids, fatty acids and sterols play in various cellular systems may yield more insight into how cellular and whole organ function is altered during the ageing process. Membrane lipid rafts (MLRs) within the plasma membrane of most cells serve as key organizers of intracellular signalling and tethering points of cytoskeletal components. MLRs are plasmalemmal microdomains enriched in sphingolipids, cholesterol and scaffolding proteins; they serve as a platform for signal transduction, cytoskeletal organization and vesicular trafficking. Within MLRs are the scaffolding and cholesterol binding proteins named caveolin (Cav). Cavs not only organize a multitude of receptors including neurotransmitter receptors (NMDA and AMPA receptors), signalling proteins that regulate the production of cAMP (G protein-coupled receptors, adenylyl cyclases, phosphodiesterases (PDEs)), and receptor tyrosine kinases involved in growth (Trk), but also interact with components that modulate actin and tubulin cytoskeletal dynamics (e.g. RhoGTPases and actin binding proteins). MLRs are essential for the regulation of the physiology of organs such as the brain, and age-related loss of cholesterol from the plasma membrane leads to loss of MLRs, decreased presynaptic vesicle fusion, and changes in neurotransmitter release, all of which contribute to different forms of neurodegeneration. Thus, MLRs provide an active membrane domain that tethers and reorganizes the cytoskeletal machinery necessary for membrane and cellular repair, and genetic interventions that restore MLRs to normal cellular levels may be exploited as potential therapeutic means to reverse the ageing and neurodegenerative processes.
Collapse
Affiliation(s)
- Junji Egawa
- Veterans Affairs San Diego Healthcare System, 3350 La Jolla Village Drive, San Diego, CA, 92161, USA
- Department of Anesthesiology, School of Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Matthew L Pearn
- Veterans Affairs San Diego Healthcare System, 3350 La Jolla Village Drive, San Diego, CA, 92161, USA
- Department of Anesthesiology, School of Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Brian P Lemkuil
- Veterans Affairs San Diego Healthcare System, 3350 La Jolla Village Drive, San Diego, CA, 92161, USA
- Department of Anesthesiology, School of Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Piyush M Patel
- Veterans Affairs San Diego Healthcare System, 3350 La Jolla Village Drive, San Diego, CA, 92161, USA
- Department of Anesthesiology, School of Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
| | - Brian P Head
- Veterans Affairs San Diego Healthcare System, 3350 La Jolla Village Drive, San Diego, CA, 92161, USA
- Department of Anesthesiology, School of Medicine, University of California, San Diego, La Jolla, CA, 92093, USA
| |
Collapse
|
45
|
Inoue R, Takata T, Fujii N, Ishii K, Uchiyama S, Sato N, Oba Y, Wood K, Kato K, Fujii N, Sugiyama M. New insight into the dynamical system of αB-crystallin oligomers. Sci Rep 2016; 6:29208. [PMID: 27381175 PMCID: PMC4933968 DOI: 10.1038/srep29208] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 06/14/2016] [Indexed: 01/21/2023] Open
Abstract
α-Crystallin possesses a dynamic quaternary structure mediated by its subunit dynamics. Elucidation of a mechanism of subunit dynamics in homo-oligomers of αB-crystallin was tackled through deuteration-assisted small-angle neutron scattering (DA-SANS) and electrospray ionization (ESI) native mass spectrometry (nMS). The existence of subunit exchange was confirmed with DA-SANS, and monomers liberated from the oligomers were observed with nMS. With increasing temperature, an increase in both the exchange rate and monomer population was observed despite the absence of oligomer collapse. It is proposed that transiently liberated subunits, namely, "traveling subunits," play a role in subunit exchange. Moreover, we propose that protein function is regulated by these traveling subunits.
Collapse
Affiliation(s)
- Rintaro Inoue
- Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka 590-0494, Japan
| | - Takumi Takata
- Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka 590-0494, Japan
| | - Norihiko Fujii
- Teikyo Univ., Radioisotope Res. Ctr, Kaga Itabashi Ku, Tokyo, 173-8605, Japan
| | - Kentaro Ishii
- Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, Okazaki 444-8787, Japan
| | - Susumu Uchiyama
- Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, Okazaki 444-8787, Japan
- Graduate School of Engineering, Osaka University, Suita, Osaka, 565-0871, Japan
| | - Nobuhiro Sato
- Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka 590-0494, Japan
| | - Yojiro Oba
- Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka 590-0494, Japan
| | - Kathleen Wood
- Australian Nuclear Science and Technology Organization, Lucas Heights, NSW Australia
| | - Koichi Kato
- Okazaki Institute for Integrative Bioscience, National Institutes of Natural Sciences, Okazaki 444-8787, Japan
| | - Noriko Fujii
- Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka 590-0494, Japan
| | - Masaaki Sugiyama
- Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka 590-0494, Japan
| |
Collapse
|
46
|
Nickels JD, Smith JC, Cheng X. Lateral organization, bilayer asymmetry, and inter-leaflet coupling of biological membranes. Chem Phys Lipids 2015; 192:87-99. [DOI: 10.1016/j.chemphyslip.2015.07.012] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Revised: 07/20/2015] [Accepted: 07/25/2015] [Indexed: 11/28/2022]
|
47
|
Marquardt D, Geier B, Pabst G. Asymmetric lipid membranes: towards more realistic model systems. MEMBRANES 2015; 5:180-96. [PMID: 25955841 PMCID: PMC4496639 DOI: 10.3390/membranes5020180] [Citation(s) in RCA: 150] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Accepted: 04/28/2015] [Indexed: 01/23/2023]
Abstract
Despite the ubiquity of transbilayer asymmetry in natural cell membranes, the vast majority of existing research has utilized chemically well-defined symmetric liposomes, where the inner and outer bilayer leaflets have the same composition. Here, we review various aspects of asymmetry in nature and in model systems in anticipation for the next phase of model membrane studies.
Collapse
Affiliation(s)
- Drew Marquardt
- Institute of Molecular Biosciences, Biophysics Division, University of Graz, NAWI Graz, Humboldtstr 50/III, Graz, 8010, Austria.
- BioTechMed-Graz, Graz, 8010, Austria.
| | - Barbara Geier
- Institute of Molecular Biosciences, Biophysics Division, University of Graz, NAWI Graz, Humboldtstr 50/III, Graz, 8010, Austria.
- BioTechMed-Graz, Graz, 8010, Austria.
| | - Georg Pabst
- Institute of Molecular Biosciences, Biophysics Division, University of Graz, NAWI Graz, Humboldtstr 50/III, Graz, 8010, Austria.
- BioTechMed-Graz, Graz, 8010, Austria.
| |
Collapse
|
48
|
Yang PW, Lin TL, Hu Y, Jeng US. A time-resolved study on the interaction of oppositely charged bicelles--implications on the charged lipid exchange kinetics. SOFT MATTER 2015; 11:2237-2242. [PMID: 25649711 DOI: 10.1039/c4sm02886d] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Time-resolved small-angle X-ray scattering was applied to study charged lipid exchange between oppositely charged disc-shaped bicelles. The exchange of charged lipids gradually reduces the surface charge density and weakens the electrostatic attraction between the oppositely charged bicelles which form alternately stacked aggregates upon mixing. Initially, at a high surface charge density with almost no free water layer between the stacked bicelles, fast exchange kinetics dominate the exchange process. At a later stage with a lower surface charge density and a larger water gap between the stacked bicelles, slow exchange kinetics take over. The fast exchange kinetics are correlated with the close contact of the bicelles when there is almost no free water layer between the tightly bound bicelles with a charged lipid exchange time constant as short as 20-40 min. When the water gap becomes large enough to have a free water layer between the stacked bicelles, the fast lipid exchange kinetics are taken over by slow lipid exchange kinetics with time constants around 200-300 min, which are comparable to the typical time constant of lipid exchange between vesicles in aqueous solution. These two kinds of exchange mode fit well with the lipid exchange models of transient hemifusion for the fast mode and monomer exchange for the slow mode.
Collapse
Affiliation(s)
- Po-Wei Yang
- Department of Engineering and System Science, National Tsing Hua University, Hsinchu, Taiwan, Republic of China.
| | | | | | | |
Collapse
|
49
|
Yesylevskyy SO, Demchenko AP. Cholesterol behavior in asymmetric lipid bilayers: insights from molecular dynamics simulations. Methods Mol Biol 2015; 1232:291-306. [PMID: 25331142 DOI: 10.1007/978-1-4939-1752-5_20] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Asymmetric lipid composition of the cell membranes plays an important role in the multitude of important biological functions. Much less is known, however, about the distribution and dynamics of cholesterol in asymmetric biological membranes. In this work we show how this issue could be addressed computationally by molecular dynamics simulations. The influence of the lipid head group charge, acyl chain saturation, spontaneous membrane curvature and the surface tension of the membrane on cholesterol distribution in asymmetric lipid bilayers is investigated. Four asymmetric bilayers containing DOPC, DOPS, DSPC, or DSPS lipids, were simulated on the time scale extended to tens of microseconds. We show that cholesterol strongly prefers anionic lipids to neutral and saturated lipid tails to unsaturated with distribution ratio ~0.4-0.6. Multiple flip-flop transitions of cholesterol were observed directly and their mean times range from 350 to 2,000 ns. It was shown that the distribution of cholesterol in the asymmetric bilayer depends not only on the type of lipids but also on the local membrane curvature and the surface tension. The geometric shape of spontaneously curved asymmetric bilayer changes dramatically in the presence of cholesterol. The membrane curvature becomes less homogeneous with large patches of flattened regions interleaved by rather sharp bends.
Collapse
Affiliation(s)
- Semen O Yesylevskyy
- Institute of Physics, National Academy of Sciences of Ukraine, Prospect Nauky, 46, Kiev, 03039, Ukraine,
| | | |
Collapse
|
50
|
Das C, Noro MG, Olmsted PD. Fast cholesterol flip-flop and lack of swelling in skin lipid multilayers. SOFT MATTER 2014; 10:7346-7352. [PMID: 25079959 DOI: 10.1039/c4sm01161a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Atomistic simulations were performed on hydrated model lipid multilayers that are representative of the lipid matrix in the outer skin (stratum corneum). We find that cholesterol transfers easily between adjacent leaflets belonging to the same bilayer via fast orientational diffusion (tumbling) in the inter-leaflet disordered region, while at the same time there is a large free energy cost against swelling. This fast flip-flop may play an important role in accommodating the variety of curvatures that would be required in the three dimensional arrangement of the lipid multilayers in skin, and for enabling mechanical or hydration induced strains without large curvature elastic costs.
Collapse
Affiliation(s)
- Chinmay Das
- School of Physics and Astronomy, University of Leeds, Leeds LS2 9JT, UK.
| | | | | |
Collapse
|