title: A density label for membranes.
abstract: Bromostearic acid satisfies the essential fatty acid requirement of an unsaturated fatty acid auxotroph of Escherichia coli K12. Over 55% of the fatty acids derived from lipids isolated from membranes of cells grown in bromostearate-supplemented medium contained bromine, as established by gas chromatography and mass spectrometry of the methyl esters. During equilibrium centrifugation in sucrose gradients, the cytoplasmic membranes isolated from bromostearate-grown cells banded at a density approximately 0.06 g/cm(3) greater than membranes isolated from oleate- or elaidate-grown cells, affording a complete separation between membranes which contain brominated fatty acids and those which do not.
mesh_terms: D001431:Bacteriological Techniques; D001966:Bromine; D002462:Cell Membrane / Q000032:analysis / Q000378:metabolism*; D002499:Centrifugation, Density Gradient; D002849:Chromatography, Gas; D003470:Culture Media; D003580:Cytochromes / Q000032:analysis; D004926:Escherichia coli / Q000254:growth & development* / Q000378:metabolism; D006027:Glycosides / Q000378:metabolism; D013058:Mass Spectrometry; D009154:Mutation; D009829:Oleic Acids / Q000378:metabolism; D013229:Stearic Acids / Q000378:metabolism*; D013385:Succinate Dehydrogenase / Q000032:analysis; D013395:Sucrose; D013696:Temperature
chemical_list: D003470:Culture Media; D003580:Cytochromes; D006027:Glycosides; D009829:Oleic Acids; D013229:Stearic Acids; D013395:Sucrose; D013385:Succinate Dehydrogenase; D001966:Bromine