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Structure of Escherichia coli membranes : Glycerol auxotrophs as a tool for the analysis of the phospholipid head-group region by deuterium magentic resonance

Gally, H. U. and Pluschke, G. and Overath, P. and Seelig, J.. (1981) Structure of Escherichia coli membranes : Glycerol auxotrophs as a tool for the analysis of the phospholipid head-group region by deuterium magentic resonance. Biochemistry, Vol. 20, H. 7. pp. 1826-1831.

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Official URL: http://edoc.unibas.ch/dok/A5257525

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Abstract

Glycerol selectively deuterated at various positions was synthesized and supplied to the growth medium of Escherichia coli strain T131 GP, which is defective in endogenous glycerol synthesis as well as glycerol degradation and lacks the ability to synthesize cardiolipin. The procedure enables the stereospecific labeling of the membrane phospholipids (approximately 80% phosphatidylethanolamine, approximately 20% phosphatdylglycerol). Deuterium magnetic resonance spectra were obtained for cell membranes and lipid dispersions either from total lipid extractions or from purified phosphitidylglycerol or -ethanolamine. When glycerol deuterated at various positions was used, all resonances of the phospholipid glycerol backbone and the terminal glycerol moiety in phosphatidylglycerol could be assigned. The results indicate that the molecular conformation of the glycerol backbone is independent of the phospholipid species investigated and is also not altered by the presence of high amounts of membrane proteins. For the quantitative interpretation of the deuterium magnetic resonance splittings, a model is proposed which assumes essentially free rotation around the glycerol C(2)-C(3) bond combined with an asymmetric and restricted jump process around the C(1)-C(2) bond. This model is compatible with known X-ray structures of phospholipids molecules. The two deuterons of both the glycerol backbone C(1) and C(3) segments were found to be magnetically inequivalent. Stereoselective monodeuteration eliminated one set of quadrupole splittings in both cases.
Faculties and Departments:05 Faculty of Science > Departement Biozentrum > Former Organization Units Biozentrum > Biophysical Chemistry (Seelig J)
UniBasel Contributors:Seelig, Joachim
Item Type:Article, refereed
Article Subtype:Research Article
Publisher:American Chemical Society
ISSN:0006-2960
Note:Publication type according to Uni Basel Research Database: Journal article
Last Modified:22 Mar 2012 14:20
Deposited On:22 Mar 2012 13:18

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