Deuterium magnetic resonance study of the gel and liquid crystalline phases of dipalmitoyl phosphatidylcholine

Davis, James H.

doi:10.1016/s0006-3495(79)85222-4

Cited by 417 publications

(282 citation statements)

References 37 publications

Supporting

Mentioning

251

Contrasting

Order By: Relevance

“…However, several studies by infrared (6,(33)(34)(35), NMR (36,37), and Raman (38, 39) spectroscopy have shown that approximately a 2-7% fraction of gauche conformers is probably already present at temperatures below the transition, accounting for an average of 0.5-1.0 gauche bond per chain. The gauche rotamers are probably located mostly in kinks (gtg') or jogs (gttg') (34,40,41), which are not too disruptive of side-to-side order in the bilayer, or form end-gauche methyl groups (38).…”

Section: Orientation Measurements Of Phospholipid Bilayersmentioning

confidence: 99%

On the relationship between the order parameter and the shape of orientation distributions

Lafrance¹,

Nabet²,

Prud’homme³

et al. 1995

Can. J. Chem.

View full text Add to dashboard Cite

The molecular orientation is generally expressed by an "order parameter," (P,), which depends on both the angular position and the shape of the orientation distribution. This parameter is an average made over all orientations of the structural units studied in a sample and, consequently, a given (P,) value can correspond to different orientation distributions. In this article, model distributions are used to show the relationship between the shape, width, and angular position of the center of the orientation distribution on the (P,) coefficient, for the case where the distribution of the molecular chains exhibits cylindrical symmetry with respect to the reference direction. A significant difference is observed between the order parameters calculated for distributions of Gaussian and Lorentzian shapes with similar width at half-height. The variation of the (P,) coefficient as a function of the width at half-height, W,,,, and of the position of the center of the distribution, 0,, is analyzed. Figures showing the range of W,,,-0, coordinates that can correspond to a given (P,) value are presented. As an example, the influence on the order parameter of the disorder between the different domains of phospholipid samples (mosaic spread) and of the conformational disorder in the acyl chains of these molecules is also studied. This example permits the evaluation of the magnitude of the errors that can be introduced in calculations of the tilt angle of the molecular chains in the case of distributions of finite widths or of bimodal character.Key words: orientation, orientation function, phospholipid bilayers, conformational disorder, mosaic spread.Resume : L'orientation molCculaire est gCnCralement exprimCe par un parambtre d'ordre, (P,), dont la valeur dCpend B la fois de la position angulaire et de la forme de la distribution d'orientation. Ce parambtre d'ordre constitue une moyenne faite sur toutes les orientations des unites structurales CtudiCes dans un Cchantillon et, en constquence, une valeur de (P,) donnCe peut correspondre 2 diffkrentes distributions d'orientation. Des distributions modkles sont utilisCes afin de montrer l'influence de la forme, de la largeur et de la position angulaire du centre de la distribution d'orientation sur le coefficient (P,), pour le cas oh les chaines molCculaires posskdent une symCtrie cylindrique par rapport B la direction de rCfCrence. Une difference significative est observCe entre les parambtres d'ordre calculCs pour des distributions de formes Gaussienne et Lorentzienne de mCme largeur i mi-hauteur. La variation du coefficient (P,) en fonction de la largeur 2 mi-hauteur, WIl2, et de la position du centre de la distribution, €Ic, est analysCe. Des figures montrant la plage de coordonnCes W,,,-0, pouvant correspondre B une valeur de parambtre d'ordre donnCe sont prCsentCes. A titre d'exemple, la variation du coefficient (P,) en fonction du dCsordre entre les diffkrents domaines dlCchantillons de phospholipides et en fonction du dCsordre conformationnel dans les chaines ...

show abstract

Section: Orientation Measurements Of Phospholipid Bilayersmentioning

confidence: 99%

On the relationship between the order parameter and the shape of orientation distributions

Lafrance¹,

Nabet²,

Prud’homme³

et al. 1995

Can. J. Chem.

View full text Add to dashboard Cite

show abstract

“…2 H-nmr order profiles using selectively deuterated phospholipids have been established now for i,2-dipalmitoyl-.JM-glycero-3-phosphocholine (DPPC) , 1975, i,3-dipalmitoyl-jn-glycero-3-phosphocholine (Seelig & Seelig, 1977;Seelig & Waespe-Sarcevic, 1978) and i,2-dipalmitoyl-.ro-glycero-3-phosphoserine (DPPS) (Seelig & Browning, 1978;Browning & Seelig, 1980). In addition, egg-yolk lecithin with perdeuterated palmitic acyl chains intercalated physically , perdeuterated i,2-dipalmitoyl-sw-glycero-3-phosphocholine (Davis, 1979) and a glycolipid (Skarjune & Oldfield, 1979) have been studied. Though limited in number these order profiles comprise a fairly representative collection of different lipid classes, including saturated and unsaturated fatty acyl chains as well as different polar groups.…”

Section: (2) Order Profiles Of Model Membranes and Biological Membranesmentioning

confidence: 99%

“…c Brown, Seelig & Haberlen (1979). A Davis (1979 microviscosity) refers to membranes in general and is independent of the specific technique employed. This is also illustrated by fluorescence spectroscopy, where it has been realized only recently that the interpretation of fluorescence depolarization measurements exclusively in terms of microviscosity is incorrect, but that the fluorescence anisotropy is equally dependent on the ordering of the fluorescent probe in the membrane (Heyn, 1979;Jahnig, 1979).…”

Section: Phospholipid Dynamics and Membrane Fluiditymentioning

confidence: 99%

Lipid conformation in model membranes and biological membranes

Seelig

1980

Quart. Rev. Biophys.

799

443

View full text Add to dashboard Cite

Protein molecules in solution or in protein crystals are characterized by rather well-defined structures in which α-helical regions, β-pleated sheets, etc., are the key features. Likewise, the double helix of nucleic acids has almost become the trademark of molecular biology as such. By contrast, the structural analysis of lipids has progressed at a relatively slow pace. The early X-ray diffraction studies by V. Luzzati and others firmly established the fact that the lipids in biological membranes are predominantly organized in bilayer structures (Luzzati, 1968). V. Luzzati was also the first to emphasize the liquid-like conformation of the hydrocarbon chains, similar to that of a liquid paraffin, yet with the average orientation of the chains perpendicular to the lipid–water interface. This liquid–crystalline bilayer is generally observed in lipid–water systems at sufficiently high temperature and water content, as well as in intact biological membranes under physiological conditions (Luzzati & Husson, 1962; Luzzati, 1968; Tardieu, Luzzati & Reman, 1973; Engelman, 1971; Shipley, 1973). In combination with thermodynamic and other spectroscopic observations these investigations culminated in the formulation of the fluid mosaic model of biological membranes (cf. Singer, 1971). However, within the limits of this model the exact nature of lipid conformation and dynamics was immaterial, the lipids were simply pictured as circles with two squiggly lines representing the polar head group and the fatty acyl chains, respectively. No attempt was made to incorporate the well-established chemical structure into this picture. Similarly, membrane proteins were visualized as smooth rotational ellipsoids disregarding the possibility that protruding amino acid side-chains and irregularities of the backbone folding may create a rather rugged protein surface.

show abstract

“…The average orientational order in the whole-lipid samples was quantified by determining the moments of the 'H-NMR spectra obtained from them (Davis, 1979). Arrhenius plots of the moments calculated from the spectra a11 increased between 30 and 0°C (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…This two-pulse sequence results in a quadrupole spin echo at a time T after the second pulse that is due to a complete refocusing of the nuclear magnetization, provided that relaxation effects can be neglected. Since dead times for spectrometers are in the range of 10 to 20 ps and relaxation times for deuterated lipids range from 100 to 500 ps (Prosser and Davis, 1992), it is usually possible to select a value of T that is much greater than the recovery time of the spectrometer but much smaller than the relaxation time (Davis, 1979(Davis, , 1983.…”

Section: Nmr Measurementsmentioning

confidence: 99%

Deuterium Magnetic Resonance Studies of Senescence-Related Changes in the Physical Properties of Rose Petal Membrane Lipids

et al. 1995

View full text Add to dashboard Cite

The physical properties of membrane lipids in senescing rose (Rosa hybrida L., cv Mercedes) petals were studied by deuterium nuclear magnetic resonance ('H-NMR) and fluorescence depolarization. AI1 of the 'H-NMR spectra arising from deuterated dimyristoylphosphatidylcholine mixed with whole-lipid extracts from membranes of petals of different ages had a shape that is characteristic of liquid-crystalline lipid at 30°C. Arrhenius plots of the moments of the 'H spectra and fluorescence depolarization values measured from 1,6-diphenyl hexatriene-labeled rose petal membrane lipid samples indicated that membrane lipid order increased with decreasing temperature as well as with increasing age of the petals. The latter trend is explained by previously observed increases in fatty acid saturation and increases in the sterol-to-phospholipid ratio that occur in rose petals during senescence. The 'H-NMR spectra obtained at 0°C also contained quadrupolar splitting lines from lipid in the gel phase, confirming the occurrence of this phase in membranes from this tissue.

show abstract

Deuterium magnetic resonance study of the gel and liquid crystalline phases of dipalmitoyl phosphatidylcholine

Cited by 417 publications

References 37 publications

On the relationship between the order parameter and the shape of orientation distributions

On the relationship between the order parameter and the shape of orientation distributions

Lipid conformation in model membranes and biological membranes

Deuterium Magnetic Resonance Studies of Senescence-Related Changes in the Physical Properties of Rose Petal Membrane Lipids

Contact Info

Product

Resources

About