Physical studies on the membranes and lipids of plasmalogen-deficient Megasphaera elsdenii

✍ Scribed by Allan E. Kaufman; Howard Goldfine; Onuttom Narayan; Sol M. Gruner

• Book ID: 103041598
• Publisher: Elsevier Science
• Year: 1990
• Tongue: English
• Weight: 631 KB
• Volume: 55
• Category: Article
• ISSN: 0009-3084
• DOI: 10.1016/0009-3084(90)90147-j

✦ Synopsis

Membrane fluidity and thermotropic phase behavior in the wild-type and plasmalogen-deficient strains of Megasphaera elsdenii have been studied by means of diphenylhexatiene steady state fluorescence anistropy in isolated membranes, and by 3tP-NMR and X-ray diffraction of the isolated phospholipids. Compared to the wild-type plasmalogen content of > 75%, plasmalogen-deficient strains had less than 5°70 plasmalogen, consistng largely of phosphatidylethanolamine and phosphatidylserine. Steady state fluorescence anistropy measurements yielded an order parameter which was 6% lower in the plasmaiogen-deficient membranes from l0 ° to 40°C, indicating higher membrane lipid mobilites. Both 3~P-NMR and X-ray diffraction revealed the formation of a hexagonal phase in the lipids from the wild-type strain starting above 30°C. In general the transition was not complete by 80°C. In contrast, phospholipids from plasmalogen-deficient strains appeared to form a relatively stable lamellar phase.