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Pullmannová P, Čuříková-Kindlová BA, Ondrejčeková V, Kováčik A, Dvořáková K, Dulanská L, Georgii R, Majcher A, Maixner J, Kučerka N, Zbytovská J, Vávrová K. Polymorphism, Nanostructures, and Barrier Properties of Ceramide-Based Lipid Films. ACS OMEGA 2023; 8:422-435. [PMID: 36643519 PMCID: PMC9835644 DOI: 10.1021/acsomega.2c04924] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 12/02/2022] [Indexed: 06/17/2023]
Abstract
Ceramides belong to sphingolipids, an important group of cellular and extracellular lipids. Their physiological functions range from cell signaling to participation in the formation of barriers against water evaporation. In the skin, they are essential for the permeability barrier, together with free fatty acids and cholesterol. We examined the periodical structure and permeability of lipid films composed of ceramides (Cer; namely, N-lignoceroyl 6-hydroxysphingosine, CerNH24, and N-lignoceroyl sphingosine, CerNS24), lignoceric acid (LIG; 24:0), and cholesterol (Chol). X-ray diffraction experiments showed that the CerNH24-based samples form either a short lamellar phase (SLP, d ∼ 5.4 nm) or a medium lamellar phase (MLP, d = 10.63-10.78 nm) depending on the annealing conditions. The proposed molecular arrangement of the MLP based on extended Cer molecules also agreed with the relative neutron scattering length density profiles obtained from the neutron diffraction data. The presence of MLP increased the lipid film permeability to the lipophilic model permeant (indomethacin) relative to the CerNS24-based control samples and the samples that had the same lipid composition but formed an SLP. Thus, the arrangement of lipids in various nanostructures is responsive to external conditions during sample preparation. This polymorphic behavior directly affects the barrier properties, which could also be (patho)physiologically relevant.
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Affiliation(s)
- Petra Pullmannová
- Skin
Barrier Research Group, Charles University, Faculty of Pharmacy in Hradec Králové, Heyrovského 1203, 500 05Hradec Králové, Czech Republic
| | - Barbora A. Čuříková-Kindlová
- Faculty
of Chemical Technology, University of Chemistry
and Technology Prague, Technická 5, 166 28Prague, Czech Republic
| | - Veronika Ondrejčeková
- Skin
Barrier Research Group, Charles University, Faculty of Pharmacy in Hradec Králové, Heyrovského 1203, 500 05Hradec Králové, Czech Republic
| | - Andrej Kováčik
- Skin
Barrier Research Group, Charles University, Faculty of Pharmacy in Hradec Králové, Heyrovského 1203, 500 05Hradec Králové, Czech Republic
| | - Kristýna Dvořáková
- Faculty
of Chemical Technology, University of Chemistry
and Technology Prague, Technická 5, 166 28Prague, Czech Republic
| | - Lucia Dulanská
- Skin
Barrier Research Group, Charles University, Faculty of Pharmacy in Hradec Králové, Heyrovského 1203, 500 05Hradec Králové, Czech Republic
| | - Robert Georgii
- Heinz
Maier-Leibnitz Zentrum (MLZ), Technische
Universität München, Lichtenbergstr. 1, 85748Garching, Germany
| | - Adam Majcher
- Skin
Barrier Research Group, Charles University, Faculty of Pharmacy in Hradec Králové, Heyrovského 1203, 500 05Hradec Králové, Czech Republic
| | - Jaroslav Maixner
- Faculty
of Chemical Technology, University of Chemistry
and Technology Prague, Technická 5, 166 28Prague, Czech Republic
| | - Norbert Kučerka
- Faculty
of Pharmacy, Comenius University Bratislava, Odbojárov 10, 832 32Bratislava, Slovakia
- Frank
Laboratory of Neutron Physics, Joint Institute
for Nuclear Research, Joliot-Curie 6, 141980Dubna, Russia
| | - Jarmila Zbytovská
- Skin
Barrier Research Group, Charles University, Faculty of Pharmacy in Hradec Králové, Heyrovského 1203, 500 05Hradec Králové, Czech Republic
- Faculty
of Chemical Technology, University of Chemistry
and Technology Prague, Technická 5, 166 28Prague, Czech Republic
| | - Kateřina Vávrová
- Skin
Barrier Research Group, Charles University, Faculty of Pharmacy in Hradec Králové, Heyrovského 1203, 500 05Hradec Králové, Czech Republic
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Malewicz B, Valiyaveettil JT, Jacob K, Byun HS, Mattjus P, Baumann WJ, Bittman R, Brown RE. The 3-hydroxy group and 4,5-trans double bond of sphingomyelin are essential for modulation of galactosylceramide transmembrane asymmetry. Biophys J 2005; 88:2670-80. [PMID: 15653730 PMCID: PMC1305363 DOI: 10.1529/biophysj.104.057059] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The structural features of SPM that control the transbilayer distribution of beta-GalCer in POPC vesicles were investigated by (13)C- and (31)P-NMR spectroscopy using lipid analogs that share physical similarities with GalCer or SPM. The SPM analogs included N-palmitoyl-4,5-dihydro-SPM, 3-deoxy-SPM, 1-alkyl-2-amidophosphatidylcholine, and dipalmitoylphosphatidylcholine, a popular model "raft lipid". The transbilayer distributions of the SPM analogs and SPM in POPC vesicles were similar by (31)P-NMR. To observe the dramatic change in GalCer transbilayer distribution that occurs when SPM is included in POPC vesicles, the 3-OH group, 4,5-trans double bond, and amide linkage all were required in SPM. However, inclusion of 2 and 10 mol % dihydroSPM in SPM/POPC (1:1) vesicles mitigated and completely abrogated the effect of SPM on the transbilayer distribution of GalCer. Despite sharing some structural features with GalCer and localizing preferentially to the inner leaflet of POPC vesicles, dimyristoylphosphatidylethanolamine did not undergo a change in transbilayer distribution when SPM was incorporated into the vesicles. The results support the hypothesis that specific interactions may be favored among select sphingolipids in curvature-stressed membranes and emphasize the potential importance of the SPM-dihydroSPM ratio in membrane fission and fusion processes associated with vesicle biogenesis and trafficking.
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Affiliation(s)
- Barbara Malewicz
- University of Minnesota, Hormel Institute, Austin, Minnesota 55912, USA
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3
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Rujoi M, Borchman D, DuPré DB, Yappert MC. Interactions of Ca(2+) with sphingomyelin and dihydrosphingomyelin. Biophys J 2002; 82:3096-104. [PMID: 12023233 PMCID: PMC1302098 DOI: 10.1016/s0006-3495(02)75651-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The changes induced by Ca(2+) on human lens sphingolipids, sphingomyelin (SM), and dihydrosphingomyelin were investigated by infrared spectroscopy. Ca(2+)-concentration-dependent studies of the head group region revealed that, for both sphingolipids, Ca(2+) partially dehydrates some of the phosphate groups and binds to others. Ca(2+) affects the interface of each sphingolipid differently. In SM, Ca(2+) shifts the amide I' band to frequencies lower than those in dehydrated samples of SM alone. This could be attributed to the direct binding of Ca(2+) to carbonyl groups and/or strong tightening of interlipid H-bonds to levels beyond those in dehydrated samples of SM only. In contrast, Ca(2+) induces relatively minor dehydration around the amide groups of dihydrosphingomyelin and a slight enhancement of direct lipid-lipid interactions. Temperature-dependent studies reveal that 0.2 M Ca(2+) increases the transition temperature T(m) from 31.6 +/- 1.0 degrees C to 35.7 +/- 1.1 degrees C for SM and from 45.5 +/- 1.1 degrees C to 48.2 +/- 1.0 degrees C for dihydrosphingomyelin. Binding of Ca(2+) to some phosphate groups remains above T(m). The strength of the interaction is, however, weaker. This allows for the partial rehydration of these moieties. Similarly, above T(m), Ca(2+)-lipid and/or direct inter-lipid interactions are weakened and lead to the rehydration of amide groups.
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Affiliation(s)
- Madalina Rujoi
- Department of Chemistry, University of Louisville, Louisville, Kentucky 40208, USA
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Talbott CM, Vorobyov I, Borchman D, Taylor KG, DuPré DB, Yappert MC. Conformational studies of sphingolipids by NMR spectroscopy. II. Sphingomyelin. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1467:326-37. [PMID: 11030591 DOI: 10.1016/s0005-2736(00)00229-7] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Sphingomyelin (SM) is the most prevalent sphingolipid in the majority of mammalian membranes. Proton and 31P nuclear magnetic resonance spectral data were acquired to establish the nature of intra- and intermolecular H-bonds in the monomeric and aggregated forms of SM and to assess possible differences between this lipid and dihydrosphingomyelin (DHSM), which lacks the double bond between carbons 4 and 5 of the sphingoid base. The spectral trends suggest the formation of an intramolecular H-bond between the OH group of the sphingosine moiety and the phosphate ester oxygen of the head group. The narrower linewidth and the downfield shift of the resonance corresponding to OH proton in SM suggest that this H-bond is stronger in SM than in DHSM. The NH group appears to be involved predominantly in intramolecular H-bonding in the monomer. As the concentration of SM increases and the molecules come in closer proximity, these intramolecular bonds are partially disrupted and the NH group becomes involved in lipid-water interactions. The difference between the SM and DHSM appears to be not in the nature of these interactions but rather in the degree to which these intermolecular interactions prevail. As SM molecules cannot come as close together as DHSM molecules can, both the NH and OH moieties remain, on average, more intramolecularly bonded as compared to DHSM.
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Affiliation(s)
- C M Talbott
- Department of Chemistry, University of Louisville, KY 40292, USA
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Ferguson-Yankey SR, Borchman D, Taylor KG, DuPré DB, Yappert MC. Conformational studies of sphingolipids by NMR spectroscopy. I. Dihydrosphingomyelin. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1467:307-25. [PMID: 11030590 DOI: 10.1016/s0005-2736(00)00228-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The conformational features of dihydrosphingomyelin (DHSM), the major phospholipid of human lens membranes, were investigated by 1H and 31P nuclear magnetic resonance spectroscopy. Several postulates emerge from the observed trends: (a) in partially hydrated samples of DHSM in CDCl3 above 13 mM, at which lipid-lipid interactions prevail, the amide proton is mostly involved in intermolecular H-bonds that link neighboring phospholipids through bridging water molecules. In the absence of water, the NH group is involved in an intramolecular H-bond that restricts the mobility of the phosphate group. (b) In the monomeric form of the lipid molecule, the amide proton of the major conformer is bound intramolecularly with one of the anionic and/or ester oxygens of the phosphate group. A minor conformer may also be present in which the NH proton participates in an intramolecular H-bond linking to the OH group of the sphingoid base. (c) Complete hydration leads to an extension of the head group as water molecules bind to the phosphate and NH groups via H-bonds, thus disrupting the intramolecular H-bonds prevalent at low concentrations.
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DuPré DB, Yappert M. Conformational simulation of phosphosphingolipids by molecular mechanics. ACTA ACUST UNITED AC 1999. [DOI: 10.1016/s0166-1280(98)00490-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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8
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Electron Crystallography of Organic Molecules. ACTA ACUST UNITED AC 1994. [DOI: 10.1016/s0065-2539(08)60548-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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9
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McIntosh TJ, Simon SA, Needham D, Huang CH. Interbilayer interactions between sphingomyelin and sphingomyelin/cholesterol bilayers. Biochemistry 1992; 31:2020-4. [PMID: 1536845 DOI: 10.1021/bi00122a018] [Citation(s) in RCA: 80] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Pressure versus fluid spacing relations have been obtained for sphingomyelin bilayers in the gel phase and equimolar sphingomyelin/cholesterol in the liquid-crystalline phase by the use of X-ray diffraction analysis of osmotically stressed aqueous dispersions and oriented multilayers. For interbilayer separations in the range of 5-20 A, the repulsive hydration pressure decays exponentially with increasing fluid spacing. The decay length (lambda) of this repulsive pressure is about 2 A for both bovine brain and N-tetracosanoylsphingomyelin, similar to that previously found for phosphatidylcholine bilayers. However, both the magnitude of the hydration pressure and the magnitude of the dipole potential (V) measured for monolayers in equilibrium with liposomes are considerably smaller for sphingomyelin than for either gel or liquid-crystalline phosphatidylcholine bilayers. Addition of equimolar cholesterol increases both the magnitude of the hydration pressure and the dipole potential. These data suggest that the magnitude of the hydration pressure depends on the electric field at the interface as given by (V/lambda)2. For sphingomyelin bilayers, there is a sharp upward break in the pressure-fluid spacing relation at an interbilayer spacing of about 5 A, indicating the onset of steric hindrance between the head groups of apposing bilayers.
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Affiliation(s)
- T J McIntosh
- Department of Cell Biology, Duke University Medical Center, Durham, North Carolina 27710
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10
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McIntosh TJ, Simon SA, Needham D, Huang CH. Structure and cohesive properties of sphingomyelin/cholesterol bilayers. Biochemistry 1992; 31:2012-20. [PMID: 1536844 DOI: 10.1021/bi00122a017] [Citation(s) in RCA: 135] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Thermal, structural, and cohesive measurements have been obtained for both bovine brain sphingomyelin (BSM) and N-tetracosanoylsphingomyelin (C24-SM) in the presence and absence of cholesterol. A goal of these experiments has been to clarify the mechanisms responsible for the strong interaction between sphingomyelin and cholesterol. Differential scanning calorimetry shows that fully hydrated bilayers of BSM and C24-SM have main endothermic phase transitions at 39 and 46 degrees C, respectively, that reflect the melting of the acyl chains from a gel to a liquid-crystalline phase. For each lipid, the addition of cholesterol monotonically reduces the enthalpy of this transition, so that at equimolar cholesterol the transition enthalpy is zero. The addition of equimolar cholesterol to either BSM or C24-SM coverts the wide-angle X-ray diffraction reflection at 4.15 A to a broad band centered at 4.5 A. Electron density profiles of gel-phase C24-SM bilayers contain two terminal methyl dips in the center of the bilayer, indicating that the lipid hydrocarbon chains partially interdigitate so that the long saturated 24-carbon acyl chains in one monolayer cross the bilayer center and appose the shorter sphingosine chains from the other monolayer. The incorporation of cholesterol adds electron density to the hydrocarbon chain region near the head group and removes the double terminal methyl dip. These wide- and low-angle X-ray data indicate that cholesterol packs into the hydrocarbon chain region near the sphingomyelin head group, fluidizes the methylene chains near the center of the bilayer compared to the gel phase, and reduces the extent of methylene chain interdigitation.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- T J McIntosh
- Department of Cell Biology, Duke University Medical Center, Durham, North Carolina 27710
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11
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Dorset DL. Direct determination of crystallographic phases for diffraction data from lipid bilayers. II. Refinement of phospholipid structures. Biophys J 1991; 60:1366-73. [PMID: 1777564 PMCID: PMC1260197 DOI: 10.1016/s0006-3495(91)82174-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Using a systematic approach for the acceptance of crystallographic phase assignment, based on the evaluation of triplet structure invariants, electron and x-ray diffraction data from phospholipid multilamellar arrays are analyzed by direct methods. After calculation of Fourier maps with a partial set of phased structure factor magnitudes, the structure is refined in real space by flattening of the hydrocarbon region of the bilayer and an optimal solution is sought either by the calculation of [delta rho 4] suggested by Luzzati, where rho is the structure density or by a test of density smoothness [magnitude of delta rho/ delta r magnitude of], where r positions are located along the normal to the lamellar surface. Reanalyses of previously determined structures sometimes lead to new conclusions (e.g., a possible similarity of the electron density profile for DL-DMPE and L-DMPE, and a clear indication of the fatty acid adduct in the mixed L-DPPC/palmitic acid bilayer). Because of presumed secondary scattering perturbations (primarily to the least intense reflections), the refinements of the electron diffraction intensities are less easily evaluated than those carried out with x-ray diffraction data.
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Affiliation(s)
- D L Dorset
- Electron Diffraction Department, Medical Foundation of Buffalo, Inc., New York 14203
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12
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Lamba OP, Borchman D, Sinha S, Lal S, Yappert M, Lou MF. Structure and molecular conformation of anhydrous and of aqueous sphingomyelin bilayers determined by infrared and Raman spectroscopy. J Mol Struct 1991. [DOI: 10.1016/0022-2860(91)85001-j] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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13
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Dorset DL. Direct determination of crystallographic phases for diffraction data from phospholipid multilamellar arrays. Biophys J 1990; 58:1077-87. [PMID: 2291934 PMCID: PMC1281054 DOI: 10.1016/s0006-3495(90)82450-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Direct determination of crystallographic phases based on probabilistic of sigma 1 and sigma 2 "triplet" structure invariants has been found to be an effective technique for structure analysis with lamellar x-ray or electron diffraction intensity data from phospholipids. In many cases, nearly all phase values are determined, permitting a structure density (electron density for x-ray diffraction; electrostatic potential for electron diffraction) map to be calculated, which is directly interpretable in terms of known bilayer lipid structure. The major source of error is found to be due to the distortion of observed electron diffraction intensity data by incoherent multiple scattering, which can significantly affect the appearance of the electrostatic potential map, but not the success of the phase determination, as long as the observed Patterson function can be interpreted.
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Affiliation(s)
- D L Dorset
- Electron Diffraction Department, Medical Foundation of Buffalo, Inc., New York 14203
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Dorset DL, Zhang WP. Lamellar packing of a chiral N,N-dimethylphosphatidylethanolamine: electron diffraction. Evidence for a lecithin-type headgroup conformation. BIOCHIMICA ET BIOPHYSICA ACTA 1990; 1028:299-303. [PMID: 2223801 DOI: 10.1016/0005-2736(90)90179-r] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Lamellar electron diffraction intensity data from epitaxially crystallized 1,2-dipalmitoyl-sn-glycerophospho-N,N-dimethylethanolamine were used to determine the layer packing in order to compare the chiral structure to the crystal structure of a racemic homologue. After finding the chain orientation, the structure was determined by interpretation of the Patterson function, followed by independent crystallographic phase assignments with conventional direct methods (use of three phase structure invariants). The phase determination was verified by a translational search with a molecular model based on a similar lecithin structure. The final R-value is 0.29, and this is lowered to 0.18 after a correction is made for incoherent multiple electron scattering. The layer packing is found to be very much like that of a diacyl phosphatidylcholine with the N,N-dimethylethanolamine moiety parallel to the bilayer surface rather than the perpendicular arrangement of headgroups involved in an interdigitated layer, as seen for racemic homolog.
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Affiliation(s)
- D L Dorset
- Electron Diffraction Department, Medical Foundation of Buffalo, Inc., NY 14203
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15
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Dorset DL, Beckmann E, Zemlin F. Direct determination of phospholipid lamellar structure at 0.34-nm resolution. Proc Natl Acad Sci U S A 1990; 87:7570-3. [PMID: 2217186 PMCID: PMC54789 DOI: 10.1073/pnas.87.19.7570] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Low-dose, high-resolution electron microscopy combined with conventional direct-phasing methods based on the estimates of triplet-structure invariants are used to determine phase values for all observed electron-diffraction-structure factor magnitudes from epitaxially oriented multilamellar paracrystals of the phosphospholipid 1,2-dihexadecyl-sn-glycerophosphoethanolamine. The reverse Fourier transform of these phase-structure factors is a one-dimensional electrostatic potential map that strongly resembles the electron-density maps calculated from similar x-ray-diffraction data. Determination of the phase values for the electron-diffraction data with structure invariants alone is nearly as successful as the combined use of two separate methods, assigning values to 13 of the 16 reflections--i.e., the electrostatic potential map closely resembles the one calculated with all data.
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Affiliation(s)
- D L Dorset
- Electron Diffraction Department, Medical Foundation of Buffalo, Inc., NY 14203
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16
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Dorset DL. Packing of linear molecules: an electron microscope study of disorder in mesophases and binary solids. JOURNAL OF ELECTRON MICROSCOPY TECHNIQUE 1989; 11:298-309. [PMID: 2723813 DOI: 10.1002/jemt.1060110409] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
With the aid of epitaxial orientation techniques originally designed for linear polymer crystallization, it is found that a large assortment of linear chain molecules can be prepared for electron diffraction study in a projection onto the molecular axes. This not only facilitates a study of ordered monodisperse molecular crystal structures but also of the disordered state as well, including thermotropic phase transitions and the structure of binary solids. Representative studies of monodisperse and polydisperse phase behavior based on electron diffraction and differential scanning calorimetry measurements are reviewed for n-paraffins, glycerolipids, and cholesteryl esters. The importance of observing the microcrystalline state is readily apparent from these studies--not only because the symmetry of individual small crystals can be determined, but also because local structural variations not detectable in bulk measurements are readily observed.
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Affiliation(s)
- D L Dorset
- Electron Diffraction Department, Medical Foundation of Buffalo, Inc., New York 14203
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Dorset DL, Pangborn WA. Polymorphic forms of 1,2-dipalmitoyl-sn-glycerol: a combined X-ray and electron diffraction study. Chem Phys Lipids 1988; 48:19-28. [PMID: 3208414 DOI: 10.1016/0009-3084(88)90130-2] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Quantitative crystallographic structure analyses are carried out for two polymorphic forms of 1,2-dipalmitoyl-sn-glycerol. A single crystal X-ray determination on the higher melting beta'L-form reveals that the hairpin conformer structure is essentially identical to that of the dilauroyl homolog reported earlier (I. Pascher, S. Sundell and H. Hauser (1981) J. Mol. Biol. 153, 791-806) with inclined acyl chain packing in the O perpendicular methylene subcell. Lamellar electron diffraction intensity data from epitaxially crystallized samples were used to determine the structure of the lower melting alpha L-form. The chains pack in the hexagonal subcell and are perpendicular to the lamellar surface. An appropriately oriented molecular model based on the beta'L-polymorph does not lead to a satisfactory structure solution but models based on the conformationally different 1,2-diglyceride moiety of several phospholipid structures does lead to a closer match to the observed diffraction data. In this proposed packing model for the alpha L-form, the hydroxyl oxygens are somewhat farther away from the unit cell origin than in the beta'L-form crystal structure, and, in combination with the different molecular conformation, this might explain the observed stability of this crystal polymorph against acyl shifts.
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Affiliation(s)
- D L Dorset
- Medical Foundation of Buffalo, Inc., NY 14203
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18
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Dorset DL. Two untilted lamellar packings for an ether-linked phosphatidyl-N-methylethanolamine. An electron crystallographic study. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 1988. [DOI: 10.1016/0005-2736(88)90166-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Dorset DL, Massalski AK. Co-solubility in binary phospholipid crystals. BIOCHIMICA ET BIOPHYSICA ACTA 1987; 903:319-32. [PMID: 3651465 DOI: 10.1016/0005-2736(87)90222-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Crystalline binary solid solutions of phosphatidylethanolamines are obtained when various fractions of compounds with different chain lengths are dissolved in chloroform and allowed to evaporate to dryness. Phase diagrams and electron diffraction measurements on chain mixtures with a difference of two or four methylene groups indicate that solubility is continuous, although non-ideal. Average molecular volume appears to increase according to Vegard's rule although deviations are noted. These deviations are similar to those observed for binary paraffin solids. Substitution of ether-links for ester-links in one component does not alter solubility behavior. In general the rules of solid solution formation appear to conform to those originally proposed by Kitaigorodskii [1961) Organic Chemical Crystallography, pp. 231-240, Consultants Bureau, New York).
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Affiliation(s)
- D L Dorset
- Electron Diffraction Department, Medical Foundation of Buffalo, Inc. 14203
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20
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Dorset DL. Electron diffraction structure analysis of phospholipids. JOURNAL OF ELECTRON MICROSCOPY TECHNIQUE 1987; 7:35-46. [PMID: 3506048 DOI: 10.1002/jemt.1060070105] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The use of lamellar electron diffraction data from epitaxially oriented phospholipid crystals for quantitative structure analysis is described in this review of the technique. It is seen that an appropriate correction for crystal texture, which is justified by the analysis of low-dose lattice images, enables these intensity data to be used much as they would be used in X-ray crystallography. Analyses of two classes of phospholipids are reviewed, revealing that the recently determined lamellar structures of ether-linked phosphatidylethanolamine and phosphatidylcholine and quite similar to the acyl-chain structures. Preliminary analysis of 1,2-dihexadecyl-sn-glycerophospho-N-methyl ethanolamine indicates that the headgroup conformation may be similar to that of the ether-linked lecithin.
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Affiliation(s)
- D L Dorset
- Electron Diffraction Department, Medical Foundation of Buffalo, Inc., New York 14203
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Dorset DL. Molecular packing of a crystalline ether-linked phosphatidylcholine: an electron diffraction study. BIOCHIMICA ET BIOPHYSICA ACTA 1987; 898:121-8. [PMID: 3828334 DOI: 10.1016/0005-2736(87)90030-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Electron diffraction data from solution- and epitaxially-crystallized samples of 1,2-dihexadecyl-sn-glycerophosphocholine are used in an analysis of its molecular packing in the minimally hydrated crystal form. The molecular chain axes are found to be perpendicular to the bilayer plane and the chains pack in the hexagonal methylene subcell. Translational search of a model based on a known diacyl phosphatidylcholine crystal structure indicates that a crystallographic residual minimum corresponds to a headgroup packing distance similar to values found for the dipalmitoyl analog at low relative humidity. The bilayer packing for the ether-linked phosphatidylcholine is therefore similar to the one reported for a sphingomyelin.
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23
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ESR study of the interaction of manganous ions with zwitterionic phospholipids and their mixtures with cholesterol. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 1984. [DOI: 10.1016/0005-2736(84)90443-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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24
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Murthy NS, Worthington CR. X-ray diffraction analysis of dehydrated myelin. BIOCHIMICA ET BIOPHYSICA ACTA 1982; 689:451-456. [PMID: 7126560 DOI: 10.1016/0005-2736(82)90302-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Improved X-ray diffraction data from dry nerve myelin are presented. In addition to the spacing of approx. 150 A, 44 A and 34.6 A, which have been previously reported, we identify a 14 A series. The data suggests that the hydrocarbon chains in the single bilayer (approximately equal to 60 A) is ordered, whereas in the double bilayer (approximately equal to 150 A) and in the fluid phase (approximately equal to 44 A) it is disordered. It is shown that cholesterol (approximately equal to 34.6 A) exists as a bilayer, and the 14 A series is probably another cholesterol phase.
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Siminovitch DJ, Jeffrey KR. Orientational order in the choline headgroup of sphingomyelin: A 14N-NMR study. BIOCHIMICA ET BIOPHYSICA ACTA 1981; 645:270-8. [PMID: 6895037 DOI: 10.1016/0005-2736(81)90198-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
An aqueous dispersion of fully hydrated bovine sphingomyelin was studied using 14N-NMR spectroscopy. Spectra were obtained as a function of temperature over the range 15-80 degrees C, in both the liquid crystal and gel phases. In the liquid crystal phase, powder pattern lineshapes were obtained, whose quadrupolar splitting slowly decreases with increasing temperature. The spectra are increasingly broadened as the temperature is lowered through the phase transition into the gel phase. The linewidths and the second moments of these spectra indicate that the onset of a broad phase transition occurs at approx. 35 degrees C, in agreement with previous calorimetric and 31 P-NMR measurements. There is no evidence from the lineshapes for an hexagonal phase in this system, and this conclusion is supported by X-ray diffraction measurements carried out on aqueous dispersions of sphingomyelin in both phases. Assuming that the static nitrogen quadrupole coupling constant is the same for both sphingomyelin and dipalmitoyl-L-alpha-phosphatidylcholine (DPPC), the decrease observed in the quadrupolar splitting of sphingomyelin compared to that of DPPC indicates that the orientational order of the choline headgroup in liquid crystalline sphingomyelin is not the same as that of its counterpart in DPPC. Preliminary relaxation time measurements of T1 and T2 are presented which suggest that there are also dynamic differences between sphingomyelin and DPPC in the choline headgroup.
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Hui SW, Stewart TP, Yeagle PL. Temperature-dependent morphological and phase behavior of sphingomyelin. BIOCHIMICA ET BIOPHYSICA ACTA 1980; 601:271-81. [PMID: 7407170 DOI: 10.1016/0005-2736(80)90532-5] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Aqueous dispersions of bovine brain sphingomyelin were studied as a function of temperature. 31P-NMR, X-ray diffraction, and negative-stain and freeze-fracture electron microscopy were used to determine the morphology and phase structure at several temperatures. 31P-NMR indicated a change in phase structure with an increase in temperature. Evidence was found only for the lamellar phase at all temperatures studied with X-ray diffraction. Electron microscopy unexpectedly revealed the spontaneous development of small unilamellar vesicles at elevated temperatures, consistent with the 31P-NMR data, in the absence of any outside disturbances.
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