Bilayers of phosphatidyldiacylglycerol and phosphatidylcholesterol give 31P-NMR spectra characteristic for hexagonal and isotropic phases

Noggle, Joseph H.; Marecek, James F.; Mandal, Sukhendu; Venetië, R.; Rogers, Joseph M.; Jain, Mahendra Kumar; Ramírez, Fausto

doi:10.1016/0005-2736(82)90413-8

Cited by 31 publications

(6 citation statements)

References 10 publications

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“…This direct comparison of NMR and X-ray diffraction data shows that in our system, as in most cases described, 31P NMR line shape does correspond to a particular phospholipid conformation. Exceptions from this generalization have been predicted theoretically and by computer simulations (Thayer & Kohler, 1981;Banerjee et al, 1985) and have been reported experimentally (Hui et al, 1981;Noggle et al, 1982). Similar results as ours were observed on a somewhat different system (yeast PC) by Dawson et al (1984) where an isotropic 31P NMR peak was observed at 15-25 mol % DO at 25-37 °C, and the signal typical of the Hn phase appeared upon increase of the DO content to 33 mol %.…”

Section: Discussionsupporting

confidence: 90%

Effects of diacylglycerols on the structure of phosphatidylcholine bilayers: a deuterium and phosphorus-31 NMR study

Boeck

Zidovetzki²

1989

Biochemistry

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The interaction of four diacylglycerols (DAGs) with multilamellar phospholipid bilayers consisting either of dipalmitoylphosphatidylcholine (DPPC) or of a mixture of DPPC and bovine liver phosphatidylcholine (BL-PC) extracts was investigated by a combination of 31P and 2H NMR spectrometry. We found that saturated and unsaturated long-chain DAGs induce different types of perturbations into the bilayer structure. The saturated DAGs dipalmitin and distearin induce lateral phase separation of the lipids into (i) DAG-enriched gellike domains and (ii) relatively DAG-free regions in the liquid-crystalline phase. In the latter regions, the order parameters along the fatty acyl chains of DPPC are practically identical with the control. This phase separation effect was observed in both model systems studied, and its extent is dependent upon DAG concentration and temperature. Only bilayer phases were present upon addition of dipalmitin or distearin at all concentrations and temperatures studied. The unsaturated DAGs diolein and DAG derived from egg PC (egg-DAG) affect PC bilayers in the following two ways: (i) by increasing the order parameters of the side chains, as observed for both DPPC and BL-PC model systems; (ii) by inducing nonbilayer lipid phases, as observed for BL-PC, but not DPPC. At a concentration of 25 mol % of an unsaturated DAG in mixed PC bilayers, a peak corresponding to isotropic lipid conformation appeared and increased in intensity with increase in temperature, while at 32 mol % hexagonal and bilayer phases coexisted.(ABSTRACT TRUNCATED AT 250 WORDS)

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Section: Discussionsupporting

confidence: 90%

Effects of diacylglycerols on the structure of phosphatidylcholine bilayers: a deuterium and phosphorus-31 NMR study

Boeck

Zidovetzki²

1989

Biochemistry

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“…The 31 P NMR resonance for hexagonal phases is markedly different from that found for a cubic or micellar phase, for which a narrow (fwhm ∼ 2 ppm) isotropic (symmetric) resonance would be expected. , Here however, the spectral line shape at 3 °C shows a deviation from an isotropic Lorentzian form. This sort of narrow, anisotropic spectrum lacking a well-resolved high-field shoulder observed at 3 °C has been previously observed in aqueous dispersions of diacylphosphatidylcholesterol and is believed to indicate the presence/formation of smaller structures (i.e., short hexagonal tubes), leading to additional motional averaging arising from particle tumbling and/or lateral diffusion of the lipids . Taken together, these results suggest that the structure of the fluid phase of the quaternary composition should be viewed as a hexagonal array of elongated/prolate structures, rather than of infinite cylinders.…”

Section: Resultssupporting

confidence: 71%

Structure and Optical Properties of a Thermoresponsive Polymer-Grafted, Lipid-Based Complex Fluid

1998

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We report herein an example of a self-assembling, stimulus-responsive complex fluid that switches between two distinct structural (two-dimensional (2-D) to one-dimensional supramolecular architecture) and functional (fluid to gel and nonbirefringent to birefringent) states in response to modest temperature changes. This complex fluid is formed by the noncovalent self-assembly of a quaternary mixture of a phospholipid, dimyristolyphosphatidylcholine (DMPC), a lipopolymer consisting of poly(ethylene oxide) terminally grafted onto the phosphate headgroup of DMPE (DMPE-EO45), and a cosurfactant, lauryldi-methylamine N-oxide (LDAO), dispersed in water. The supramolecular assembly formed by this mixture has been found to undergo a reversible transformation from a liquid-crystalline gel to a nonbirefringent fluid upon reduction in temperature. The onset of the thermotropic phase transition has been determined to be 16 °C by differential scanning calorimetry (DSC). The structural organization (i.e., the supramolecular architecture) of the noncovalent aggregate above and below this phase transition has been probed on a range of length scales (i.e., macrosopic, mesoscopic, and nanoscopic) using polarized optical microscopy (POM), small angle neutron scattering (SANS), transmission Fourier transform infrared (FT-IR) spectroscopy, and phosphorus-31 nuclear magnetic resonance (31P NMR) spectroscopy. The line shape of the 31P NMR resonance of the fluid phase indicates hexagonal structural ordering. Low-resolution crystallographic structure analysis using SANS confirms the 31P NMR findings, indicating that the structure consists of a 2-D hexagonal (space group p6m) array of cylinders with the distance between the center of adjacent tubes (i.e., lattice spacing) of 345 Å. The topology of the phase has been found to be a normal hexagonal structure, H1, in which the hydrocarbon chains fill the interior of the cylinders, and the cylinders are immersed in a water continuum. The absence of birefringence in the fluid phase under crossed polarizers is believed to arise from the shortened axis of the cylinders. Structural characterization by 31P NMR and SANS demonstrates that the gel phase comprises microdomains of lamellae with a lattice spacing of 153 Å. The lamellar structure, however, is a high defect structure, as evidenced by POM and the broad Bragg peaks in the small-angle neutron diffraction profile. Evaluation of the conformational state of the hydrocarbon chains by transmission FT-IR spectroscopy indicates high gauche content (type α), providing evidence that gelation is not a consequence of alkyl chain ordering.

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“…Such sharp peaks were described in several experiments in which glycophorin was chemically back inserted with other lipids (De Kruijff et al, 1991 ;Taraschi et al, 1982) and they were present in other systems in which peptides were inserted in lipids (Zidovetzki et al, 1988;Killian et al, 1990). Such sharp peaks are associated with high mobility of the polar head region in pure lipid systems but theoretical simulations showed that a small change in the orientation of the polar head caused a drastic modification in 31P-NMR anisotropy (Thayer and Kohler, 1981 ;Banerjee et al, 1985;Noggle et al, 1982). We previously described such a simulation by using the framework provided by others (Thayer and Kohler, 1981).…”

Section: Discussionmentioning

confidence: 86%

Insertion of Glycophorin A, A Transmembraneous Protein, in Lipid Bilayers can be Mediated by Electropermeabilization

Raffy

Teissié

1995

European Journal of Biochemistry

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Transmembraneous back-insertion of a solubilized membrane protein, glycophorin A, has been obtained in 1,2 dipalmitoyl-sn-glycero-3-phosphocholine (Pam,GroPCho) cell-size-like liposomes by submitting the lipidprotein mixture to calibrated electric field pulses. Field conditions which are prone to trigger glycophorin insertion are similar to those which mediate lipid layer electropermeabilization. The efflux of calcein, trapped in the liposomes during their preparation, was observed only when field strength is higher than 1.3 kV/cm. Electroinsertion was detected only above the same critical field intensity. Calcein efflux as well as glycophorin insertion were increased by increasing field intensity, pulse duration andor number of pulses. Experimental evidence of protein insertion was provided by physico-chemical as well as biochemical methods. Direct observation of the pulsed vesicles under the microscope revealed the insertion by means of immunofluorescence and fluorescence. Electroinsertion of fluorescent glycophorin A revealed that the inner bilayers were also labeled. The gel-to-liquid phase transition temperature of Pam,GroPCho decreased after insertion but its cooperativity was not affected. A narrow 3'P-NMR peak was observed after electroinsertion showing that the polar headgroups of phospholipids had been altered. Analysis of trypsin-digested peptides revealed that the two trans-orientations of the protein across the external lipid layer were present after electroinsertion. Localized perturbation of the polar headgroup region of phospholipids, which supports the transient permeabilization of lipid layers, allows spontaneous transinsertion of glycophorin across the lipid bilayers.

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Bilayers of phosphatidyldiacylglycerol and phosphatidylcholesterol give 31P-NMR spectra characteristic for hexagonal and isotropic phases

Cited by 31 publications

References 10 publications

Effects of diacylglycerols on the structure of phosphatidylcholine bilayers: a deuterium and phosphorus-31 NMR study

Effects of diacylglycerols on the structure of phosphatidylcholine bilayers: a deuterium and phosphorus-31 NMR study

Structure and Optical Properties of a Thermoresponsive Polymer-Grafted, Lipid-Based Complex Fluid

Insertion of Glycophorin A, A Transmembraneous Protein, in Lipid Bilayers can be Mediated by Electropermeabilization

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