PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 4943174

A density label for membranes.

C F Fox·J H Law·N Tsukagoshi·G Wilson
View original source ↗Export metadata ↓

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.

Explore related subjects

Bacteriological TechniquesBromineCell MembraneCentrifugation, Density GradientChromatography, GasCulture MediaCytochromesEscherichia coliGlycosidesMass SpectrometryMutationOleic AcidsStearic AcidsSuccinate DehydrogenaseSucroseTemperatureJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

C F Fox, J H Law, N Tsukagoshi, G Wilson. 1970. A density label for membranes.. https://doi.org/10.1073/pnas.67.2.598

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2007

Fatty acids synthesized by oral treponemes in chemically defined media.

OMIZ-W68, a chemically defined medium that contains no long-chain fatty acids and yet supports in vitro proliferation of a wide range of fastidious oral anaerobes, is described. The type strains of Treponema denticola, Treponema lecithinolyticum, Treponema maltophilum, Treponema pectinovorum, Treponema socranskii, and an as yet unpublished canine Treponema species could be propagated indefinitely in this medium with sugar supplements for the saccharolytic species. Analysis of the cellular fatty acids (CFA) of these treponemes by gas chromatography demonstrated the synthesis of C14, C15, C16, and C17 fatty acids (linear-, iso-, and anteiso-forms) in various proportions, but neither hydroxy- nor unsaturated fatty acids. However, between 0% and 40% of the eluted material could not be identified. The proportions of CFAs differed not only between species but also between the eight strains of Treponema denticola investigated. Replacing OMIZ-W68 by a derivative minimal essential medium (OMIZ-M/TDCDK) developed for Treponema denticola had little effect on the CFA profiles. In contrast, the CFA profiles of treponemes grown in OMIZ-W68 showed at best minor similarity to the strains from the Moore library of the Virginia Polytechnic Institute, which had been grown in media containing serum, peptones, and yeast extract.

Bacteriological Techniques↗
PubMed2007

Specificity of catecholamine-induced growth in Escherichia coli O157:H7, Salmonella enterica and Yersinia enterocolitica.

The present study demonstrates that catecholamine responsiveness in Yersinia enterocolitica, a bacterial pathogen whose infectious spectrum is principally limited to the gut, is limited to norepinephrine and dopamine, and not epinephrine; this behavior contrasts with observations for two pathogens with a wider extra-gastrointestinal spectrum, Escherichia coli O157:H7 and Salmonella enterica, which respond to all three catecholamines. Epinephrine showed lower potency than norepinephrine and dopamine in inducing growth of E. coli and S. enterica, and was a potent antagonist of norepinephrine and dopamine growth responsiveness in Y. enterocolitica. Given that only norepinephrine and dopamine and not epinephrine-containing neurons are found with the enteric nervous system, the results suggest that certain of the more exclusive enteric pathogens may have developed response systems preferentially for those neuroendocrine hormones that are produced by the enteric nervous system as host-derived signals by which to sense the environment and initiate pathogenic processes.

Bacteriological Techniques↗