Water binding and phase structures for different Acholeplasma laidlawii membrane lipids studied by deuteron nuclear magnetic resonance and x-ray diffraction

Wieslander, Åke; Ulmius, Jan; Lindblom, Göran; Fontell, Krister

doi:10.1016/0005-2736(78)90250-x

Cited by 154 publications

(112 citation statements)

References 28 publications

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“…This transition temperature is strongly dependent on the fatty-acyl chain composition. Saturated species can only form a bilayer, while egg phosphatidylethanolamine adopts the hexagonal HH phase at about 25°C and dioleoylphosphatidylethanolamine at about 5 ° C. Other membrane lipids like cardiolipin [4,6,7] and monoglucosyldiacylglycerol [8,9] also adopt the hexagonal H H phase at physiological temperature. Most interestingly, in mixtures of these lipids with phosphatid choline, lipidic particles of an inverted micellar nature associated with the bilayer have been observed both by freeze-fracture electron microscopy and by 31P-NMR [9,10].…”

Section: Discussionmentioning

confidence: 99%

A possible role of rhodopsin in maintaining bilayer structure in the photoreceptor membrane

Grip

Drenthe

Echteld

et al. 1979

Biochimica et Biophysica Acta (BBA) - Biomembranes

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Summary31p-NMR measurements demonstrate that at 37 ° C, independent of the photolytic state of the photopigment rhodopsin, the lipids in the photoreceptormembrane are almost exclusively organised in a bilayer. In strong contrast, the 31P-NMR spectra of the extracted lipids are characteristic for the hexagonal HII phase and an isotropic phase. The isotropic phase is characterised by freeze-fracture electron microscopy as particles and pits on smooth surfaces, possibly indicating inverted micelles. These results suggest a structural role for rhodopsin in maintaining the photoreceptor membrane lipids in a bilayer configuration.It has recently been demonstrated that the lipid bilayer, while still the basic feature of biological membranes, is not the only conformational state in which the lipids in membranes can occur. 31P-NMR studies have presented strong evidence that in the endoplasmic reticulum of rat, bovine and rabbit liver the phospholipids can undergo isotropic motion, which suggests that inverted micellar structures may be present in conjunction with the bilayer [ 1 ]. Model studies of water-phospholipid mixtures show that the preferred phase depends on the type of lipid [ 2--6 ]. Under most conditions the thermodynamically most stable phase of phosphatidylcholine is the bilayer. Unsaturated phosphatidylethanolamine also prefers the bilayer conformation at lower temperatures, but at increasing temperature it undergoes a phase Abbreviation: Mops, 3-(N-morpholino)propanesulfonic acid.

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Section: Discussionmentioning

confidence: 99%

A possible role of rhodopsin in maintaining bilayer structure in the photoreceptor membrane

Grip

Drenthe

Echteld

et al. 1979

Biochimica et Biophysica Acta (BBA) - Biomembranes

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“…For example, unsaturated phosphatidylethanolamine (PE) from eukaryotic cells [17,18] and E. col[ [19], monogalactosyldiacylglycerol (MGalDG) from chloroplasts [20] and monoglucosyldiacylglycerol (MGIucDG) from Acholeplasma laidlawii [3,21] adopt the HI, phase at physiological temperatures. The tendency of other naturally occurring lipids, like cardiolipin [13,22,23] and phosphatidic acid [8~24], to form the H n phase is dependent on pH and the presence of divalent cations.…”

Section: Iia Hexagonal II Phase Lipidsmentioning

confidence: 99%

Lipidic intramembranous particles

Verkleij

Momvers

Leunissen‐Bijvelt

et al. 1979

Nature

204

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“…Finally 11 (w/w) of 'H20 was added. The samples were flushed with NZ and the deuterated water was mixed with the lipids by extended centrifugation at 45 "C. The deuterated water concentration used is slightly lower than the maximum hydration capacities of these lipids [2,15]. Water concentrations above these limits were avoided since free water may complicate the interpretation of the N M R spectra.…”

Section: Sumple Preparationmentioning

confidence: 99%

“…We have recently shown that thc regulation of lipid composition is a mechanism whereby A. luidluwii always secures an optimal bilayer stability [14]. The regulation is expressed as an alteration in the relative syntheses of the two dominating lipids AcylzGlcGro and diacyldiglucosylglycerol (Acyl2Glcz-Gro), the latter lipid forming a lamellar phase [2]. The amount of ionic lipids is also changed [14].…”

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confidence: 99%

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The Effect of Cholesterol on the Phase Structure of Glucolipids from Acholeplasma laidlawii Membranes

Khan¹,

Rilfors

Wieslander

et al. 1981

Eur J Biochem

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1. The packing properties in lipid mixtures containing cholesterol and membrane glucolipids from Acholcplusma luidluwii are modified by varying the amounts of cholesterol, diacylmonoglucosylglycerol and diacyldiglucosylglycerol in the mixtures as well as the temperature and the degree of acyl chain unsaturation. These changes affect both the proportions of different lipids having dissimilar molecular geometries and the geometry of the lipid molecules themselves.2. All mixtures containing glucolipids with equal amounts of palmitoyl and oleoyl chains formed a lamellar liquid-crystalline phase in the growth temperature range of A . luidluwii, while a reversed cubic liquid-crystalline phase dominated in mixtures containing dioleoyl glucolipids. These lipids formed a reversed hexagonal phase together with 27 cholesterol. Mixtures with lipid compositions occurring in the membranes of living Acholcplusma cells formed a lamellar liquid-crystalline phase.3. Large amounts of cholesterol and diacylmonoglucosylglycerol, high temperatures and a high degree of cis unsaturation favoured the formation of cubic or hexagonal liquid-crystalline phase structures of the investigated lipid mixtures. Diacylmonoglucosylglycerol and cholesterol are both wedge-shaped. Temperature and cis unsaturation accentuate the wedge-shape properties of the glucolipid molecules.4. The changes in the lipid composition of A . laidlawfi membranes as a response to cholesterol incorporation can be explained by the geometry and packing characteristics of the sterol molecule and the concept of 'fluidity' does not need to be involved.The organization of membrane components is governed by energetic, entropic and steric constraints, and the thermodynamically possible ways to pack the components together are limited by these constraints. The geometry of amphiphiles is of particular importance for the formation of lipid aggregates with different shapes [I]. The lamellar phase is a prerequisite for obtdining a stable, insulating biological menibrane. However, most of such membranes contain significant amounts of at least one lipid species which, owing to its molecular shape, cannot form a lamellar phase. It has been proposed that local regions of lipids forming non-lamellar structures may be advantageous to certain membrane functions [l 1. Diacylmonoglucosylglycerol (Acy12GlcGro) forms a reversed hexagonal (HI!) phase with different acyl chain contents [2], while phosphatidylethanolamine exhibits a lamellar or an HI, phase depending on temperature, acyl chain content and pH [3]. Acyl2GlcGro and unsaturated phosphat idylethanolamine can be pictured as truncated cones. Cholesterol is a flat, rigid molecule compared to lipids containing flexible chains and does not form bilayers at physiological temperatures [l]. Cholesterol has been observed to deslabilize the bilayer structure of dioleoylglycerophosphoethanolamine as wcll as a mixture of soya phosphatidylethanolamine and egg-yolk phosphatidylcholine [4]. Large amounts of

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Water binding and phase structures for different Acholeplasma laidlawii membrane lipids studied by deuteron nuclear magnetic resonance and x-ray diffraction

Cited by 154 publications

References 28 publications

A possible role of rhodopsin in maintaining bilayer structure in the photoreceptor membrane

A possible role of rhodopsin in maintaining bilayer structure in the photoreceptor membrane

Lipidic intramembranous particles

The Effect of Cholesterol on the Phase Structure of Glucolipids from Acholeplasma laidlawii Membranes

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