Application | Comment | Organism |
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analysis | rapid, selective, and sensitive liquid chromatography-tandem mass spectrometry assay for the simultaneous quantification of the metabolites and precursors of the activated methyl cycle. Analytes are extracted from Escherichia coli MG1655 and chemically derivatized as N(O,S)-iso-butyloxycarbonyl iso-butyl esters using iso-butyl chloroformate in an aqueous iso-butanol/pyridine environment. S-Adenosylmethionine, S-adenosylhomocysteine, S-ribosylhomocysteine, homocysteine, methionine, cystathionine, cysteine, and homoserine are quantified by liquid chromatography-positive ion tandem electrospray ionization mass spectrometry. Internal standards are isotopically labeled [13CD3]methionine and S-adenosylcysteine. Linearity of the assay is established up to a concentration of 700 microg/g cell dry weight for each analyte | Escherichia coli |
Organism | UniProt | Comment | Textmining |
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Escherichia coli | - |
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General Information | Comment | Organism |
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physiological function | mutation of luxS leads to profound differences in activated methyl cycle metabolite concentrations. Unable to metabolize these substrates, the concentration of S-ribosylhomocysteine continues to accrue throughout their growth. By the stationary phase, the concentration of ribosylhomocysteine in the DELTAluxS mutant is approximately 460fold higher when compared with that in the wild-type strain. Homocysteine is significantly lower in the mutant when compared with the wild-type | Escherichia coli |