Monolayer properties of chloroplast lipids

Bishop, David G.; Kenrick, Janette R.; Bayston, James H.; Macpherson, Athol S.; Johns, S. R.

doi:10.1016/0005-2736(80)90308-9

Cited by 53 publications

(18 citation statements)

References 36 publications

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“…Furthermore, A~ is also similar to the corresponding value obtained from X-ray diffraction of the crystalline material. For DGDG, the experimental AI values are between 83 ~2 (Bishop et al 1980) and 87 ,~2 (Marra 1985), in good agreement with the theoretical determinations of Brasseur et al (1983), that is, 85/~2. In this regard, it is noteworthy that these values may vary considerably with the biological origin of the lipid (see, e.g., Bishop et al 1980), thereby indicating structural differences in their fatty acid chains.…”

Section: Intramolecular H-bonding In the Polar Head Of Dgdgsupporting

confidence: 74%

Fourier transform infrared spectroscopic study of ion binding and intramolecular interactions in the polar head of digalactosyldiacylglycerol

Menikh

Fragata

1993

Eur Biophys J

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Lipid bilayers composed of digalactosyldiacylglycerol (DGDG), that is, Galp alpha 1-6Galp beta 1-3DAG, a non-ionic lipid of the thylakoid membrane of chloroplasts, aggregate in aqueous media containing mono- and divalent cations in amounts above a threshold concentration (Ct) of about 1.0, 4.7 and 10.0 mM for Ca2+, Mg2+ and Na+, respectively. In this work, we found that above Ct the DGDG membranes do not undergo fusion and that the aggregation can be reversed or disrupted. This means that the perturbation induced by the salts results from adsorption, or complexation of the ions in the polar head of DGDG. To investigate this question, we used Fourier transform infrared (FTIR) spectroscopy to identify the molecular sites in DGDG which are modified by interaction, or adduct formation with CaCl2, MgCl2 and NaCl. We also determined whether the ions affect the intramolecular hydrogen bonding between the sn2 ester C = O and the carbon-6 of the alpha-anomer of galactose (Gal). The major conclusions are: (i) the salts do not affect, at least directly, the ester carbonyl region of DGDG, (ii) the most probable sites of binding, or adsorption, for the ions are the ring oxygen, and (iii) the ring hydroxyls are the sites of either ion complexation or intra- and intermolecular H-bonding in interacting DGDG membranes. Within this framework, the complexation of the ions with Gal might induce total or partial dehydration of the galactolipid headgroup and thus provides the means to overcome the repulsive hydration forces that hinder aggregation of the DGDG membranes.

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Section: Intramolecular H-bonding In the Polar Head Of Dgdgsupporting

confidence: 74%

Fourier transform infrared spectroscopic study of ion binding and intramolecular interactions in the polar head of digalactosyldiacylglycerol

Menikh

Fragata

1993

Eur Biophys J

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“…The uncharged galactose headgroup of MGDG is difficult to hydrate; rather then hydrogen bonding to water, it is expected that strong hydrogen bonds will be formed between adjacent galactose headgroups. This has been demonstrated in studies of monolayers of MGDG, where stronger interactions are observed between MGDG molecules than between phosphatidylcholines with comparable degrees of chain unsaturation [13]. It is possible that it is this hydrogen bonding potential that leads to the formation of stacked membranes in the presence of MGDG.…”

Section: Stacked Thylakoid Membranesmentioning

confidence: 84%

Membrane lipids: It’s only a phase

Lee

2000

Current Biology

107

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“…Physical chemical studies of purified GL have determined that the phase transition temperatures of hydrogenated DGDG is about 30°C lower than that of equivalent MGDG (4). The more bulky digalactosyl group appears to have a strong fluidizing effect not shown by the monogalactosyl moiety.…”

Section: Effects Ofmentioning

confidence: 99%

Low Temperature-Induced Alterations in the Chloroplast and Microsomal Membranes of Dunaliella salina

Lynch

Thompson²

1982

Plant Physiol.

126

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The metabolic regulation of membrane lipid composition has been examined using the cell wall-less, unicellular green alga Dunwaiela salina (UTEX 1644) as a model system. Low temperature stress was employed to initiate and study the We have undertaken a comprehensive study of membrane metabolism and physical properties in the eukaryotic plant cell, using the unicellular green alga Dunaliella salina as a model system. This alga has many unique properties which make it a useful experimental system. For example, it grows rapidly under axenic conditions to yield a population of very homogeneous cells. Being naturally wall-less, Dunaliella is easily disrupted, facilitating cell fractionation. The lipid composition of Dunaliella is typical of green algae and similar to that of higher plants. It is able to tolerate a wide range of temperatures and salinities (6), making it useful for investigating the role of the membrane in response to environmental stresses.A certain amount of information concerning the lipids of Dunaliella is already available (13). In this communication we report additional data of the type needed for a detailed analysis of intracellular membrane lipid dynamics. We have employed a shift in growth temperature as a means of altering membrane properties and lipid metabolism. Although a thorough understanding of the effects of low temperature on plant cells is lacking, it is clear that the cell membranes and their constituent lipids change in response to chilling (14). Studying the rate and the extent of lipid change in chloroplasts and microsomes during low temperature acclimation affords a sensitive tool for identifying the contributions of the two lipid synthesizing organelles to the plant cell's membrane economy.In recent years, much progress has been made in understanding the lipid metabolism, physical properties, and physiological role of biological membranes (25). Experimental evidence, derived mainly from microorganisms and higher animals, strongly suggests that the physiological functioning of a membrane is dependent upon its physical state (fluidity) and that the physical state is itself a function of the membrane lipid composition (24).Progress toward understanding the role of lipids in determinin'g properties of plant membranes has been more difficult for several reasons. The cellular heterogeneity of plant tissues and the pres-

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Monolayer properties of chloroplast lipids

Cited by 53 publications

References 36 publications

Fourier transform infrared spectroscopic study of ion binding and intramolecular interactions in the polar head of digalactosyldiacylglycerol

Fourier transform infrared spectroscopic study of ion binding and intramolecular interactions in the polar head of digalactosyldiacylglycerol

Membrane lipids: It’s only a phase

Low Temperature-Induced Alterations in the Chloroplast and Microsomal Membranes of Dunaliella salina

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