31P- and 1H-NMR investigations of the effect of n-alcohols on the hydrolysis by phospholipase A2 of phospholipid vesicular membranes

Kaszuba, Michael; Hunt, G.R.A.

doi:10.1016/0005-2736(90)90242-g

Cited by 13 publications

(8 citation statements)

References 22 publications

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“…Although the contribution of the isotropic line to the total spectrum is not significantly different between the two systems when in the same phase (i.e., DMPE at 320 K and PE at 300 K), typical line widths measured on the resolved isotropic line of the DMPE/RCD system are narrower (20 Hz) than those measured on the PE/RCD samples (30)(31)(32)(33)(34)(35). This result suggests that the associated species PE/ RCD and DMPE/RCD are different, either in their degree of aggregation or in their dynamic properties.…”

Section: Experimentssmentioning

confidence: 97%

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Mechanism of α-Cyclodextrin Induced Hemolysis. 2. A Study of the Factors Controlling the Association with Serine-, Ethanolamine-, and Choline-Phospholipids

Debouzy¹,

Fauvelle²,

Crouzy³

et al. 1998

Journal of Pharmaceutical Sciences

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A nuclear magnetic resonance (NMR) spectroscopy and molecular modeling study of the interaction between alpha-cyclodextrin (alpha-CD) and phospholipids with serine, ethanolamine, or choline headgroups is presented. The experimental approach is based on 31P and 1H NMR measurements on small unilamellar vesicles (SUV), multilamellar systems (MLV), and aqueous suspensions of lipids using a direct complex preparation with alpha-CD. Molecular dynamics computer simulations are used to investigate the trajectory of alpha-CD in the vicinity of a membrane surface and the influence of the charge and dipole moment of the phospholipid headgroups. These factors of charge and orientation of dipole moment seem to play a key role in the interaction of phospholipids with alpha-CD and reflect very well the experimentally observed selectivity of the phospholipid -alpha-CD approach. However, with this approach, there is no evidence for the formation of a complex with the phospholipid headgroup (except for phosphatidylinositol) that results from electrostatic forces. Rather, after a possible extraction of the lipid from the membrane, a classical inclusion of the sn-2 chain in the cavity of alpha-CD occurs. This step depends on the alkyl chain length and saturation state of the lipids as well as on their organization (i.e., as vesicles or dispersions). Based on our results, chemical modifications of the alpha-CD molecule to control the hemolytic properties of alpha-CD are discussed.

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Section: Experimentssmentioning

confidence: 97%

“…On the other hand, when a bilayer structure is present, the protons of the internal layer are not accessible to the paramagnetic ions and the corresponding resonances are not shifted. 32 At this step, one can reasonably propose that a complex is formed, giving rise to the resolved lines detected both by 1 H and 31 P NMR.…”

Section: Experimentssmentioning

confidence: 98%

Mechanism of α-Cyclodextrin Induced Hemolysis. 2. A Study of the Factors Controlling the Association with Serine-, Ethanolamine-, and Choline-Phospholipids

Debouzy¹,

Fauvelle²,

Crouzy³

et al. 1998

Journal of Pharmaceutical Sciences

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“…Adsorption of phenyltin compound molecules to the lipid bilayer causes desorption of praseodymium ions, which shows as a change of signal splitting. [23][24][25] Therefore, the decrease in signal splitting might be used as a measure of the amount of adsorbed phenyltin compound. Figure 6 shows the percentage of praseodymium ions released from the membrane as a function of the concentration of organotin compound in the sample (the desorption was estimated from the extent of signal splitting).…”

Section: Nmr Measurementsmentioning

confidence: 99%

Effect of phenyltin compounds on lipid bilayer organization

Langner

Gabrielska

Kleszczyńska

et al. 1998

Appl. Organometal. Chem.

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Phenyltin compounds are known to be biologically active. Their chemical structure suggests that they are likely to interact with the lipid fraction of cell membranes. Using fluorescence and NMR techniques, the effect of phenyltin compounds on selected regions of model lipid bilayers formed from phosphatidylcholine was studied. The polarization of N‐(7‐nitrobenz‐2‐oxa‐1,3‐diazol‐4‐yl) dipalmitoyl‐L‐phosphatidylethanolamine and desorption of praseodymium ions was used to probe the polar region, whereas the polarization of 1 ‐ (4 ‐ trimethylammoniumphenyl) ‐ 6 ‐ phenyl ‐ 1,3,5‐hexatriene p‐toluenesulfonate measured the hydrophobic core of the membrane. In addition, changes in the N‐(5‐fluoresceinthiocarbanoly)dipalmitoyl ‐ L ‐ α ‐ phosphatidyl ‐ ethanolamine fluorescence intensity indicated the amount of charge introduced by organotin compounds to the membrane surface. There were no relevant changes of measured parameters when tetraphenyltin was introduced to the vesicle suspension. Diphenyltin chloride causes changes of the hydrophobic region, whereas the triphenyltin chloride seems to adsorb in the headgroup region of the lipid bilayer. When the hemolytic activity of phenyltin compounds was measured, triphenyltin chloride was the most effective whereas diphenyltin chloride was much less effective. Tetraphenyltin causes little damage. Based on the presented data, a correlation between activity of those compounds to hemolysis (and toxicity) and the location of the compound within the lipid bilayer could be proposed. In order to inflict damage on the plasma membrane, the compound has to penetrate the lipid bilayer. Tetraphenyltin does not partition into the lipid fraction; therefore its destructive effect is negligible. The partition of the compound into the lipid phase is not sufficient enough, by itself, to change the structure of the lipid bilayer to a biologically relevant degree. The hemolytic potency seems to be dependent on the location of the compound within the lipid bilayer. Triphenyltin chloride which adsorbs on the surface of the membrane, causes a high level of hemolysis, whereas diphenyltin chloride, which penetrates much deeper, seems to have only limited potency. © 1998 John Wiley & Sons, Ltd.

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“…As a consequence, the chemical environment of protons from the analysed compounds changes as does the dipolar interaction of protons with unpaired electrons of the metal, which results in changes in the chemical shift but with the coupling constants remaining unchanged. The chemical shift depends on the metal-proton distance and decreases with its increase (Jones & Hunt, 1985;Kaszuba & Hunt, 1990). Interesting signals are obtained in the 1 H-NMR spectrum from protons of choline methyl groups in individual layers of the vesicles; in the 31 P-NMR spectrum, in turn, signals come from phosphorus atoms located in the hydrophilic part of phospholipids with differentiation into individual lipid layers of the model membrane.…”

mentioning

confidence: 97%

“…The presence of the paramagnetic Pr 3+ ions permits observation of separate signals from the hydrophilic part of the inner and outer lipid bilayers because of the changes in the chemical shift of the signals (Hunt & Tipping, 1978;Hunt & Jawaharlal, 1980;Hunt & Jones, 1983). The praseodymium ions form unstable associates with oxygen atoms in the phosphate group and increase their coordination number (Jones & Hunt, 1985;Kaszuba & Hunt, 1990;Gabrielska & Gruszecki, 1996). As a consequence, the chemical environment of protons from the analysed compounds changes as does the dipolar interaction of protons with unpaired electrons of the metal, which results in changes in the chemical shift but with the coupling constants remaining unchanged.…”

mentioning

confidence: 99%

Application of (1)H and (31)P NMR to topological description of a model of biological membrane fusion: topological description of a model of biological membrane fusion.

Janiak-Osajca¹,

Timoszyk²

2012

Acta Biochim Pol

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The process of biological membrane fusion can be analysed by topological methods. Mathematical analysis of the fusion process of vesicles indicated two significant facts: the formation of an inner, transient structure (hexagonal phase - H(II)) and a translocation of some lipids within the membrane. This shift had a vector character and only occurred from the outer to the inner layer. Model membrane composed of phosphatidylcholine (PC), phosphatidylethanolamine (PE) and phosphatidylserine (PS) was studied. (31)P- and (1)H-NMR methods were used to describe the process of fusion. (31)P-NMR spectra of multilamellar vesicles (MLV) were taken at various temperatures and concentrations of Ca(2+) ions (natural fusiogenic agent). A (31)P-NMR spectrum with the characteristic shape of the H(II) phase was obtained for the molar Ca(2+)/PS ratio of 2.0. During the study, (1)H-NMR and (31)P-NMR spectra for small unilamellar vesicle (SUV), which were dependent on time (concentration of Pr(3+) ions was constant), were also recorded. The presence of the paramagnetic Pr(3+) ions permits observation of separate signals from the hydrophilic part of the inner and outer lipid bilayers. The obtained results suggest that in the process of fusion translocation of phospholipid molecules takes place from the outer to the inner layer of the vesicle and size of the vesicles increase. The NMR study has showed that the intermediate state of the fusion process caused by Ca(2+) ions is the H(II) phase. The experimental results obtained are in agreement with the topological model as well.

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31P- and 1H-NMR investigations of the effect of n-alcohols on the hydrolysis by phospholipase A2 of phospholipid vesicular membranes

Cited by 13 publications

References 22 publications

Mechanism of α-Cyclodextrin Induced Hemolysis. 2. A Study of the Factors Controlling the Association with Serine-, Ethanolamine-, and Choline-Phospholipids

Mechanism of α-Cyclodextrin Induced Hemolysis. 2. A Study of the Factors Controlling the Association with Serine-, Ethanolamine-, and Choline-Phospholipids

Effect of phenyltin compounds on lipid bilayer organization

Application of (1)H and (31)P NMR to topological description of a model of biological membrane fusion: topological description of a model of biological membrane fusion.

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