Composition and phase behaviour of polar lipids isolated from Spirulina maxima cells grown in a perdeuterated medium.
The lipid composition of Spirulina maxima cells grown in a perdeuterated medium was determined by using nuclear magnetic resonance spectroscopy, fast atom-bombardment-mass spectrometry, gas chromatography-mass spectrometry as well as conventional chemical methods. The extent of deuteration was determined by mass spectrometry and was superior to 97.5%. The major lipids identified in the strain were: non-polar lipids (9%), monogalactosyldiacylglycerol (5%), digalactosyldiacylglycerol (22%), phosphatidylglycerol (31%), sulfoquinovosyldiacylglycerol (32%), phosphatidylinositol (traces). The major fatty acids were 16:0 (80%) and 18:1 (15%). These results demonstrate that the adaptation of the cells to D2O did not imply a profound modification of the lipid composition. The perdeuterated polar lipid mixture dispersed into an excess of water organises spontaneously in a lamellar phase as seen by 31P and deuterium solid state NMR and can therefore be used to prepare perdeuterated model membranes with a well defined composition. Liposomes made using these lipids have a gel to liquid-crystalline phase transition in the range 15-27 degrees C and are in a fluid L alpha phase above this temperature.
Laboratoire de Pharmacologie et de Toxicologie Fondamentales du CNRS, Université Paul Sabatier, Toulouse, France.
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Tropis
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Bardou
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Bersch
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Daffé
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Milon
D002848:Chromatography, DEAE-Cellulose; D000458:Cyanobacteria / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism*; D017666:Deuterium Oxide; D005227:Fatty Acids / Q000032:analysis; D008401:Gas Chromatography-Mass Spectrometry; D006017:Glycolipids / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D050356:Lipid Metabolism; D008055:Lipids / Q000737:chemistry / Q000302:isolation & purification; D009682:Magnetic Resonance Spectroscopy; D011865:Radioisotope Dilution Technique; D016339:Spectrometry, Mass, Fast Atom Bombardment; D017550:Spectroscopy, Fourier Transform Infrared
D005227:Fatty Acids; D006017:Glycolipids; D008055:Lipids; D017666:Deuterium Oxide