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Sukstanskii AL, Yablonskiy DA. Microscopic theory of spin-spin and spin-lattice relaxation of bound protons in cellular and myelin membranes-A lateral diffusion model (LDM). Magn Reson Med 2023; 89:370-383. [PMID: 36094730 PMCID: PMC9826187 DOI: 10.1002/mrm.29430] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 06/26/2022] [Accepted: 08/08/2022] [Indexed: 01/12/2023]
Abstract
PURPOSE Deciphering salient features of biological tissue cellular microstructure in health and diseases is an ultimate goal of MRI. While most MRI approaches are based on studying MR properties of tissue "free" water indirectly affected by tissue microstructure, other approaches, such as magnetization transfer (MT), directly target signals from tissue-forming macromolecules. However, despite three-decades of successful applications, relationships between MT measurements and tissue microstructure remain elusive, hampering interpretation of experimental results. The goal of this paper is to develop microscopic theory connecting the structure of cellular and myelin membranes to their MR properties. THEORY AND METHODS Herein we introduce a lateral diffusion model (LDM) that explains the T2 (spin-spin) and T1 (spin-lattice) MRI relaxation properties of the macromolecular-bound protons by their dipole-dipole interaction modulated by the lateral diffusion of long lipid molecules forming cellular and myelin membranes. RESULTS LDM predicts anisotropic T1 and T2 relaxation of membrane-bound protons. Moreover, their T2 relaxation cannot be described in terms of a standard R2 = 1/T2 relaxation rate parameter, but rather by a relaxation rate function R2 (t) that depends on time t after RF excitation, having, in the main approximation, a logarithmic behavior: R2 (t) ∼ lnt. This anisotropic non-linear relaxation leads to an absorption lineshape that is different from Super-Lorentzian traditionally used in interpreting MT experiments. CONCLUSION LDM-derived analytical equations connect the membrane-bound protons T1 and T2 relaxation with dynamic distances between protons in neighboring membrane-forming lipid molecules and their lateral diffusion. This sheds new light on relationships between MT parameters and microstructure of cellular and myelin membranes.
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Schyboll F, Jaekel U, Petruccione F, Neeb H. Dipolar induced spin-lattice relaxation in the myelin sheath: A molecular dynamics study. Sci Rep 2019; 9:14813. [PMID: 31616004 PMCID: PMC6794311 DOI: 10.1038/s41598-019-51003-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 09/19/2019] [Indexed: 01/25/2023] Open
Abstract
Interactions between hydrogen protons of water molecules and macromolecules within the myelin sheath surrounding the axons are a major factor influencing the magnetic resonance (MR) contrast in white matter (WM) regions. In past decades, several studies have investigated the underlying effects and reported a wide range of R1 rates for the myelin associated compartments at different field strengths. However, it was also shown that the experimental quantification of the compartment-specific R1 rates is associated with large uncertainties. The current study therefore investigates the longitudinal relaxation rates within the myelin sheath using a molecular dynamic (MD) simulation. For this purpose, a realistic molecular model of the myelin sheath was employed to determine the dipole-dipole induced R1 relaxation rate of the hydrogen protons at clinically relevant field strengths. The results obtained clearly reflect the spatial heterogeneity of R1 with a increased relaxivity of myelin water due to a reduced molecular mobility near the membrane surface. Moreover, the calculated R1 rates for both myelin water and macromolecules are in excellent agreement with experimental findings from the literature at different field strengths.
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Affiliation(s)
- Felix Schyboll
- University of Applied Sciences Koblenz, RheinAhrCampus Remagen, Remagen, Germany
| | - Uwe Jaekel
- University of Applied Sciences Koblenz, RheinAhrCampus Remagen, Remagen, Germany
| | | | - Heiko Neeb
- University of Applied Sciences Koblenz, RheinAhrCampus Remagen, Remagen, Germany.
- Institute for Medical Engineering and Information Processing - MTI Mittelrhein, University of Koblenz, Koblenz, Germany.
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van Gelderen P, Jiang X, Duyn JH. Effects of magnetization transfer on T1 contrast in human brain white matter. Neuroimage 2015; 128:85-95. [PMID: 26724780 DOI: 10.1016/j.neuroimage.2015.12.032] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 12/17/2015] [Accepted: 12/20/2015] [Indexed: 11/17/2022] Open
Abstract
MRI based on T1 relaxation contrast is increasingly being used to study brain morphology and myelination. Although it provides for excellent distinction between the major tissue types of gray matter, white matter, and CSF, reproducible quantification of T1 relaxation rates is difficult due to the complexity of the contrast mechanism and dependence on experimental details. In this work, we perform simulations and inversion-recovery MRI measurements at 3T and 7T to show that substantial measurement variability results from unintended and uncontrolled perturbation of the magnetization of MRI-invisible (1)H protons of lipids and macromolecules. This results in bi-exponential relaxation, with a fast component whose relative contribution under practical conditions can reach 20%. This phenomenon can strongly affect apparent relaxation rates, affect contrast between tissue types, and result in contrast variations over the brain. Based on this novel understanding, ways are proposed to minimize this experimental variability and its effect on T1 contrast, quantification accuracy and reproducibility.
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Affiliation(s)
- Peter van Gelderen
- Advanced MRI Section, Laboratory of Functional and Molecular Imaging, National Institutes of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Xu Jiang
- Advanced MRI Section, Laboratory of Functional and Molecular Imaging, National Institutes of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jeff H Duyn
- Advanced MRI Section, Laboratory of Functional and Molecular Imaging, National Institutes of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA.
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Schneider H, Manz B, Westhoff M, Mimietz S, Szimtenings M, Neuberger T, Faber C, Krohne G, Haase A, Volke F, Zimmermann U. The impact of lipid distribution, composition and mobility on xylem water refilling of the resurrection plant Myrothamnus flabellifolia. THE NEW PHYTOLOGIST 2003; 159:487-505. [PMID: 33873352 DOI: 10.1046/j.1469-8137.2003.00814.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
• Lipids play a crucial role in the maintenance of the structural and functional integrity of the water-conducting elements and cells of the resurrection plant Myrothamnus flabellifolia during complete dehydration. • Lipid composition, mobility and distribution within the internodal and nodal xylem regions (including short shoots and leaves) were investigated in the presence and absence of water by using various nuclear magnetic resonance (NMR) spectroscopy and imaging techniques differing greatly in the level of spatial resolution and acquisition of lipid parameters. • Significant findings include: a discontinuity in the branch xylem between an inner zone where no water moves and an outer zone where the water moves; the blocking of water movement in the inner zone by lipids that are not dispersed by water, and the facilitation of water advance in the xylem elements and pits of the outer zone by water-dispersed lipids; the relative impermeability of leaf trace xylem to the rehydrating water and, hence, the relative hydraulic isolation of the leaves. • These results elucidated part of the strategy used by the resurrection plant to cope with extreme drought and to minimize transpirational water loss upon hydration.
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Affiliation(s)
- H Schneider
- Lehrstuhl für Biotechnologie, Biozentrum der Universität, Am Hubland, D-97074 Würzburg, Germany
| | - B Manz
- Fraunhofer Institut für Biomedizinische Technik, Ensheimer Strasse 48, D-66386 St Ingbert, Germany
| | - M Westhoff
- Lehrstuhl für Biotechnologie, Biozentrum der Universität, Am Hubland, D-97074 Würzburg, Germany
| | - S Mimietz
- Lehrstuhl für Biotechnologie, Biozentrum der Universität, Am Hubland, D-97074 Würzburg, Germany
| | - M Szimtenings
- Lehrstuhl für Experimentelle Physik V (Biophysik) der Universität, Am Hubland, D-97074 Würzburg, Germany
| | - T Neuberger
- Lehrstuhl für Experimentelle Physik V (Biophysik) der Universität, Am Hubland, D-97074 Würzburg, Germany
| | - C Faber
- Lehrstuhl für Experimentelle Physik V (Biophysik) der Universität, Am Hubland, D-97074 Würzburg, Germany
| | - G Krohne
- Abteilung für Elektronenmikroskopie, Biozentrum der Universität, Am Hubland, D-97074 Würzburg, Germany
| | - A Haase
- Lehrstuhl für Experimentelle Physik V (Biophysik) der Universität, Am Hubland, D-97074 Würzburg, Germany
| | - F Volke
- Fraunhofer Institut für Biomedizinische Technik, Ensheimer Strasse 48, D-66386 St Ingbert, Germany
| | - U Zimmermann
- Lehrstuhl für Biotechnologie, Biozentrum der Universität, Am Hubland, D-97074 Würzburg, Germany
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Rodríguez CR, Pusiol DJ, Figueiredo Neto AM, Seitter RO. Slow molecular dynamics of water in a lyotropic complex fluid studied by deuterium conventional and spin-lattice relaxometry NMR. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2002; 65:031703. [PMID: 11909077 DOI: 10.1103/physreve.65.031703] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2001] [Indexed: 05/23/2023]
Abstract
A nuclear magnetic resonance study of protons and deuterons in the mesomorphic phases of the micellar lyotropic mixture potassium laurate/1-decanol/heavy water is reported. The slow dynamical behavior of water molecules has been investigated with deuterons spin-lattice relaxation dispersion in the Larmor frequency range 10(3)<nu(L)<4.2x10(7) Hz. In order to compare relative behaviors additional T1 dispersion of micellar protons has been measured in the same compound, temperature, and Larmor frequency range. From the experimental behaviors, we conclude that in the nematic phases the water slow reorientational dynamics is closely related to the slow reorientation of the micellar aggregates. In addition, conventional deuterium nuclear magnetic resonance at nu(L)=4.2x10(7) Hz spectra has been measured at different places in the phase diagram. The line shapes show a quadrupolar splitting in nematic phases, meanwhile in the isotropic phase the spectral structure collapses in a single line. This indicates that in the nematic phases the water reorientations are not enough to average the deuterons quadrupolar Hamiltonian. On the other hand, fast isotropic water reorientations reduce the quadrupolar interactions in the isotropic phase.
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Affiliation(s)
- C R Rodríguez
- Facultad de Matemática, Astronomía y Física, Universidad Nacional de Córdoba, Ciudad Universitaria, X5016LAE Córdoba, Argentina
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Kurze V, Steinbauer B, Huber T, Beyer K. A (2)H NMR study of macroscopically aligned bilayer membranes containing interfacial hydroxyl residues. Biophys J 2000; 78:2441-51. [PMID: 10777740 PMCID: PMC1300833 DOI: 10.1016/s0006-3495(00)76788-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The polar interface of membranes containing phosphatidylglycerol or cholesterol was studied by (2)H nuclear magnetic resonance (NMR) as a function of membrane hydration. The membranes were macroscopically aligned and hydrated with deuterium oxide. Water uptake and membrane annealing was achieved under NMR control, using a novel hydration technique. Well-resolved (2)H quadrupolar doublets were obtained from individual hydroxyl residues and from the interlamellar water. The response of the phosphatidylglycerol headgroup and of the cholesterol molecule to the spontaneous evaporation of interlamellar water could be thus monitored continuously. It is shown that the phosphatidylglycerol headgroup undergoes changes of conformation and average orientation with respect to the membrane surface and that the off-axis motion of the cholesterol molecule decreases. The deuteron exchange between hydroxyl residues and surface-associated D(2)O was determined by an inversion transfer technique. The exchange rates of the hydroxyl residues in the phosphatidylglycerol headgroup were different and depended strongly on the total hydration of the membrane. Significantly lower and almost hydration-independent rates were obtained for cholesterol. These results will be discussed with reference to earlier reports on the headgroup dynamics of phosphatidylglycerol and on the interaction of cholesterol with the membrane-water interface.
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Affiliation(s)
- V Kurze
- Adolf-Butenandt-Institut, Lehrstuhl für Stoffwechselbiochemie der Universität München, 80336 München, Germany
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Wassall SR. Pulsed field gradient-spin echo NMR studies of water diffusion in a phospholipid model membrane. Biophys J 1996; 71:2724-32. [PMID: 8913609 PMCID: PMC1233758 DOI: 10.1016/s0006-3495(96)79463-8] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Water diffusion in the lamellar phase of egg phosphatidylcholine (egg PC)-water was studied by 1H NMR using the pulsed field gradient-spin echo method. The curvature of diffusion plots obtained with egg PC-water mixtures indicates that water diffusion is highly anisotropic with respect to lipid lamellae. This was confirmed by measurements made on macroscopically aligned egg PC-water as a function of orientation that categorically establish DII/DI >> .1, where the respective subscripts refer to parallel and perpendicular to the lipid bilayer. A smooth, monotonic dependence on water concentration was observed for water diffusion in aligned egg PC-water, varying at 25 degrees C from DII = 1.2 x 10(-10) m2 s 1 at n = 4.9 mol water/lipid to DII = 4.0 x 10(-10) m2 s-1 at n = 18.6 mol water/lipid. The diffusion is approximately a factor of 10 slower than in pure water because of water binding and restriction to translational motion within the aqueous layer. No evidence for a sudden drop in water diffusion coefficient at a specific water content, as previously reported with egg PC-water mixtures (Lange and Gary Bobo. 1974. J. Gen. Physiol 63:690-706), was detected. A morphological reorganization of lamellar domains, which in random orientational distribution comprise lipid-water mixtures, is the likely explanation. The study of aligned lipid-water systems is manifestly preferable.
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Affiliation(s)
- S R Wassall
- Department of Physics, Indiana University-Purdue University Indianapolis, 46202-3273, USA. ieaz
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8
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Eisenblätter S, Galle J, Volke F. Spin—lattice relaxation of 2H2O at amphiphile/water interfaces as seen by NMR. Chem Phys Lett 1994. [DOI: 10.1016/0009-2614(94)00901-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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9
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Volke F, Eisenblätter S, Galle J, Klose G. Dynamic properties of water at phosphatidylcholine lipid-bilayer surfaces as seen by deuterium and pulsed field gradient proton NMR. Chem Phys Lipids 1994; 70:121-31. [PMID: 8033284 DOI: 10.1016/0009-3084(94)90080-9] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The dynamic properties of water in phosphatidylcholine lipid/water dispersions have been studied, applying a combination of 2H-NMR techniques (quadrupole splitting and spin-lattice relaxation time) and self-diffusion measurements using pulsed filed gradient (PFG) 1H-NMR. The hydration properties of POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylcholine) were compared with those of DOPC (1,2-dioleoyl-sn-glycero-3-phosphatidylcholine) and EYL (egg yolk phosphatidylcholine (lecithin)). A model is presented that assumes an exponentially decaying influence of the bilayer surface on water dynamics as well as on water orientation with increasing hydration. This assumption is based on an exponentially decaying hydration potential which results from direct lipid-water and water-water interactions. The model describes successfully the experimental data for a large water concentration range, especially at low hydration, where other models failed. With the exception of a small fraction of water which is significantly influenced by the surface in slowing down the mobility, the interbilayer water has isotropic, free water characteristics in terms of correlation times and molecular order. Hydration properties of POPC are comparable with those of EYL but differ from DOPC. At very low water content the correlation times of headgroup segmental reorientation and water are similar, indicating a strong coupling of this water to the lipid lattice. The hydration properties of the three lipids studied are explained in terms of slightly different headgroup conformations due to different lateral packing of the molecules by their fatty acid chain composition.
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Affiliation(s)
- F Volke
- Department of Physics, University of Leipzig, Germany
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10
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Hydrogen bonding Part 55. IR and thermodynamic study of the lower hydrates of phenylphosphorylcholine and methylphosphorylcholine. J Mol Struct 1994. [DOI: 10.1016/0022-2860(93)07930-u] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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11
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König S, Sackmann E, Richter D, Zorn R, Carlile C, Bayerl TM. Molecular dynamics of water in oriented DPPC multilayers studied by quasielastic neutron scattering and deuterium‐nuclear magnetic resonance relaxation. J Chem Phys 1994. [DOI: 10.1063/1.466422] [Citation(s) in RCA: 93] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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12
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Arnold K, Gawrisch K. Effects of fusogenic agents on membrane hydration: a deuterium nuclear magnetic resonance approach. Methods Enzymol 1993; 220:143-57. [PMID: 8394491 DOI: 10.1016/0076-6879(93)20080-m] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- K Arnold
- Institute of Biophysics, Faculty of Medicine, University of Leipzig, Germany
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13
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Price WS, Kuchel PW, Cornell BA. A 35Cl and 37Cl NMR study of chloride binding to the erythrocyte anion transport protein. Biophys Chem 1991; 40:329-37. [PMID: 1912291 DOI: 10.1016/0301-4622(91)80030-u] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Band 3, the erythrocyte anion transport protein, mediates the one-for-one exchange of bicarbonate and chloride ions across the membrane and consequently plays an important role in respiration. Binding to the protein forms the first step in the translocation of the chloride across the membrane. 35Cl and 37Cl NMR relaxation measurements at various field strengths were used to study chloride binding to the protein in the presence and absence of the transport inhibitor 4,4'-dinitrostilbene-2,2'-disulfonate. Significant differences occurred in the NMR relaxation rates depending on whether the inhibitor was present or not. The results indicate that the rate of chloride association and dissociation at each external binding site occurs on a time scale of less than or equal to 5 microseconds. This implies that the transmembrane flux is not limited by the rate of chloride binding to the external chloride binding site of band 3. The rotational correlation-time of chloride bound to band 3 was found to be greater than 20 ns with a quadrupole coupling constant of approximately 2 MHz.
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Affiliation(s)
- W S Price
- Department of Biochemistry, University of Sydney, NSW, Australia
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14
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Takahashi A, Takizawa T, Nakata Y. Temperature dependence of proton spin-lattice relaxation time for water (HDO) in dipalmitoylphosphatidylcholine-D2O systems. Chem Phys Lett 1989. [DOI: 10.1016/0009-2614(89)80012-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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15
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On the ordering of N-alkane and N-alcohol solutes in phospholipid bilayer model membrane systems. Chem Phys Lipids 1984. [DOI: 10.1016/0009-3084(84)90051-3] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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16
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Abstract
Phosphatidylcholines were incorporated into hexagonal liquid crystalline mixtures of the non-ionic detergents Triton X-100 and octaethyleneglycoldodecylether with D2O. It is shown by nuclear magnetic resonance (NMR) that the phospholipids adopt the hexagonal liquid crystalline structure of the detergent host lattice. The anisotropic motion of the phospholipid headgroups seems to be unaffected, whereas the acyl chains are disordered. Increasing phospholipid concentration leads to separation of a lamellar phase. The lamellar structure is also preferred at elevated temperatures. Phosphatidylcholines with saturated acyl chains undergo a transition from the hexagonal liquid crystalline to an ordered lamellar state. The shape of the 31P-NMR signals suggests that pure gel phase phospholipid separates out. The headgroup region of this gel phase phospholipid becomes immobilized after a few weeks of storage below the transition temperature as judged from 31P-NMR. At the same time 2H-NMR exhibits a new signal from D2O undergoing slow isotropic motion. This behavior bears resemblance to the formation of a coagel in fatty acid-water systems.
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18
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Grabielle-Madelmont C, Perron R. Calorimetric studies on phospholipid—water systems. J Colloid Interface Sci 1983. [DOI: 10.1016/0021-9797(83)90208-4] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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19
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Beyer K. Phase structures, water binding, and molecular dynamics in liquid crystalline and frozen states of the system Triton X-100-D2O. J Colloid Interface Sci 1982. [DOI: 10.1016/0021-9797(82)90042-x] [Citation(s) in RCA: 63] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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20
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Pope JM, Walker L, Cornell BA, Francis GW. NMR study of synthetic lecithin bilayers in the vicinity of the gel-liquid--crystal transition. Biophys J 1981; 35:509-20. [PMID: 7272448 PMCID: PMC1327539 DOI: 10.1016/s0006-3495(81)84806-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
1H, 2H, and 31P NMR methods have been employed in the study of dimyristoyl lecithin bilayers hydrated with D2O in the gel (L beta'), intermediate (P beta') and liquid-crystalline (L alpha) phases. For D2O/lipid molar ratios, n, in the range 7 less than or equal to n less than or equal to 11 discontinuities are observed in the deuterium NMR splittings at both main and pretransitions. A partial phase diagram based on NMR and differential scanning calorimetry data is presented. 1H NMR dipolar splittings are observed for macroscopically oriented samples in all three phases. Changes in the 1H splittings are correlated with 2H and 31P data and interpreted to show that the chain tilt in the gel phase undergoes a discontinuous change on transition to the intermediate phase, which brings the chain axes closer to the bilayer normal. An estimate of chain tilt in the gel phase is made on the basis of NMR data and found to be approximately 23 degrees for a sample with n = 11 at 18 degrees C.
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21
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Cornell B. The effect of the bilayer phase transition on the carbonyl carbon-13 chemical shift anisotropy. Chem Phys Lipids 1981. [DOI: 10.1016/0009-3084(81)90035-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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22
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Cornell B, Pope J. Low frequency and diffusive motion in aligned phospholipid multilayers studied by pulsed NMR. Chem Phys Lipids 1980. [DOI: 10.1016/0009-3084(80)90020-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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23
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24
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A pulsed NMR study of lipids, bound water and sodium ions in macroscopically-oriented lecithin/water lyotropic liquid crystal model membrane systems. Chem Phys Lipids 1979. [DOI: 10.1016/0009-3084(79)90093-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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25
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Tricot Y, Niederberger W. Water orientation and motion in phospholipid bilayers: a comparison between 17O- and 2H-NMR. Biophys Chem 1979; 9:195-200. [PMID: 454799 DOI: 10.1016/0301-4622(79)85001-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
17O- and 2H-NMR spectra were obtained of a lamellar phase of dipalmitoyl-3sn-phosphatidylcholine (DPL) and D2 17O with water content of 3--15 moles water/mole DPL, in the temperature range 20 to 80 degrees C. In every case, the quadrupole splittings observed for 17O were 6.6 times larger than those for 2H. Therefore the two methods contain in principle the same information, but with less details from 17O. On the other hand, dynamic information is easily obtained from 17O linewidth data and complements the deuterium results.
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Hauser H, Phillips M. Interactions of the Polar Groups of Phospholipid Bilayer Membranes. ACTA ACUST UNITED AC 1979. [DOI: 10.1016/b978-1-4831-9993-1.50010-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
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27
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NMR Studies of Model Biological Membrane Systems: Unsonicated Surfactant-Water Dispersions. ACTA ACUST UNITED AC 1978. [DOI: 10.1016/b978-0-12-571812-7.50007-3] [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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28
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Wilkinson DA, Morowitz HJ, Prestegard JH. Hydration of phosphatidylocholine. Adsorption isotherm and proton nuclear magnetic resonance studies. Biophys J 1977; 20:169-79. [PMID: 911980 PMCID: PMC1473388 DOI: 10.1016/s0006-3495(77)85542-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Adsorption-desorption isotherms were obtained for water binding by 1,2-dimyristoylphosphatidylcholine in the temperature range 15 degrees-35 degrees C. The isotherms were analyzed by Brunauer et al.'s (BET) theory and also a polarization theory, the latter being more successful in fitting the data. There was some evidence for a change in the surface field of the lipid bilayer around 25 degrees C. Proton T1 and T2 measurements were used to obtain a log-normal molecular correlation time distribution for water protons in these systems. This distribution was compared with the isotherm data to effect a description of several classes of water molecules.
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29
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Klose G, Hempel G. Benzene-lecithin interaction interaction in lecithin-benzene solutions. Part L Magnetic deuterium relaxation studies. Chem Phys Lipids 1977; 18:274-84. [PMID: 870215 DOI: 10.1016/0009-3084(77)90015-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
2D relaxation times of deuterobenzene in lecithin-benzene solutions were measured at 4.4 and 11 MHz with respect to concentration and temperature. At the temperature of the transition from the micellar solution to the gel state the relaxation behaviour was drastically changed. Analysis of the experimental results performed on the basis of familiar relaxation theory shows that there are sites at which benzene interacts with lecithin in the micellar solution as well as in the gel state. The interaction enthalpies and entropies determined for the two benzene species existing in the gel state are--1.3 kcal/mol,--20 eu and--3.1 kcal/mol, --24 eu.
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