Dynamics of the phosphate group in phospholipid bilayers. A 31P nuclear relaxation time study

Milburn, M.P.; Jeffrey, Kenneth R.

doi:10.1016/s0006-3495(87)83273-3

Cited by 37 publications

(37 citation statements)

References 32 publications

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“…The 31P NMR lineshapes are very characteristic of the different phases, such as the gel and liquid-crystalline lamellar phases, the inverted hexagonal phase, and isotropic phases such as small vesicles and micelles (Seelig, 1978;Smith and Ekiel, 1984;Lindblom and Rilfors, 1989;Seddon, 1990a). On the other hand, the dynamics of the lipid headgroup can be studied by 31p NMR longitudinal relaxation time (T1) (Milburn and Jeffrey, 1987) and 31P NMR transversal relaxation time (T2) (Dufourc et al, 1992).…”

Section: Introductionmentioning

confidence: 99%

Model of interaction between a cardiotoxin and dimyristoylphosphatidic acid bilayers determined by solid-state 31P NMR spectroscopy

Picard

Pézolet

Bougis

et al. 1996

Biophysical Journal

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The interaction of cardiotoxin IIa, a small basic protein extracted from Naja mossambica mossambica venom, with dimyristoylphosphatidic acid (DMPA) membranes has been investigated by solid-state 31P nuclear magnetic resonance spectroscopy. Both the spectral lineshapes and transverse relaxation time values have been measured as a function of temperature for different lipid-to-protein molar ratios. The results indicate that the interaction of cardiotoxin with DMPA gives rise to the complete disappearance of the bilayer structure at a lipid-to-protein molar ratio of 5:1. However, a coexistence of the lamellar and isotropic phases is observed at higher lipid contents. In addition, the number of phospholipids interacting with cardiotoxin increases from about 5 at room temperature to approximately 15 at temperatures above the phase transition of the pure lipid. The isotropic structure appears to be a hydrophobic complex similar to an inverted micellar phase that can be extracted by a hydrophobic solvent. At a lipid-to-protein molar ratio of 40:1, the isotropic structure disappears at high temperature to give rise to a second anisotropic phase, which is most likely associated with the incorporation of the hydrophobic complex inside the bilayer.

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Section: Introductionmentioning

confidence: 99%

Model of interaction between a cardiotoxin and dimyristoylphosphatidic acid bilayers determined by solid-state 31P NMR spectroscopy

Picard

Pézolet

Bougis

et al. 1996

Biophysical Journal

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“…The experimental uncertainty in the measurement of T, was -10%. This is a factor of two larger than the uncertainty in the 31p spin lattice relaxation times reported previously (8) for multilamellar dispersions of egg lecithin. The increase is a result of changing hydration of the samples during a measurement on a single sample and from sample to sample.…”

Section: Introductionmentioning

confidence: 60%

“…At intermediate frequencies both mechanisms contribute to the measured relaxation time. A minimum occurred in the relaxation time measured as a function of temperature, and the position of this minimum was seen to be a function of frequency (8).…”

Section: Introductionmentioning

confidence: 88%

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Dynamics of the phosphate group in phospholipid bilayers. A 31P angular dependent nuclear spin relaxation time study

Milburn

Jeffrey

1989

Biophysical Journal

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To understand 31P relaxation processes and hence molecular dynamics in the phospholipid multilayer it is important to measure the dependence of the 31P spin-lattice relaxation time on as many variables as the physical system allows. Such measurements of the 31P spin-lattice relaxation rate have been reported both as a function of Larmor frequency and temperature for egg phosphatidylcholine liposomes (Milburn, M.P., and K.R. Jeffrey. 1987. Biophys. J. 52:791-799). In principle, the spin-lattice relaxation rate in an anisotropic environment such as a bilayer will be a function of the angle between the bilayer normal and the magnetic field. However, the measurement of this angular dependence has not been possible because the rapid (on the time-scale of the spin-lattice relaxation rate) diffusion of the lipid molecules over the curved surface of the liposome average this dependence (Milburn, M.P., and K.R. Jeffrey. 1987. Biophys. J. 52:791-799; Brown, M.F., and J.H. Davis. 1981. Chem. Phys. Lett. 79:431-435). This paper reports the results of the measurement of the 31P spin-lattice relaxation rate as a function of this angle, beta', (the angle between the bilayer normal and the external magnetic field) using samples oriented between glass plates. These measurements were made at high field (145.7 MHz) where the spin-lattice relaxation processes are dominated by the chemical shielding interaction (Milburn, M.P., and K.R. Jeffrey. 1987. Biophys. J. 52:791-799). A model of molecular motion that includes a fast axially symmetric rotation of the phosphate group (tau i approximately 10(-9) s) and a wobble of the head group tilt with respect to this rotation axis has been used to describe both the angular dependence of the spin-lattice relaxation and the spectral anisotropy. Cholesterol is seen to have a negligible effect on the motional properties of the phospholipid phosphate segment as measured by the orientation dependence of the spin-lattice relaxation.

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“…In the liquid crystal state, τ ||′ is in the nanosecond range. 18,19 The dynamics of the phospholipid headgroups and the hydrocarbon chains are not the same. τ ||′ for the headgroups is an order of magnitude shorter than τ || for the hydrocarbon chains.…”

Section: Phospholipid Headgroup Motionsmentioning

confidence: 99%

Lipid Dynamics in Membranes

Yèagle

2016

The Membranes of Cells

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Dynamics of the phosphate group in phospholipid bilayers. A 31P nuclear relaxation time study

Cited by 37 publications

References 32 publications

Model of interaction between a cardiotoxin and dimyristoylphosphatidic acid bilayers determined by solid-state 31P NMR spectroscopy

Model of interaction between a cardiotoxin and dimyristoylphosphatidic acid bilayers determined by solid-state 31P NMR spectroscopy

Dynamics of the phosphate group in phospholipid bilayers. A 31P angular dependent nuclear spin relaxation time study

Lipid Dynamics in Membranes

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