Analysis of Amino Acid Isotopomers Using FT-ICR MS

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• 作者：Francesco Pingitore ; Yinjie Tang ; Gary H. Kruppa ; Jay D. Keasling
• 刊名：Analytical Chemistry
• 出版年：2007
• 出版时间：March 15, 2007
• 年：2007
• 卷：79
• 期：6
• 页码：2483 - 2490
• 全文大小：159K
• 年卷期：v.79,no.6(March 15, 2007)
• ISSN：1520-6882

文摘

Fluxes through known metabolic pathways and the presence of novel metabolic reactions are often determinedby feeding isotopically labeled substrate to an organismand then determining the isotopomer distribution inamino acids in proteins. However, commonly used techniques to measure the isotopomer distributions requirederivatization prior to analysis (gas chromatography/massspectrometry (GC/MS)) or large sample sizes (nuclearmagnetic resonance (NMR) spectroscopy). Here, wedemonstrate the use of Fourier transform-ion cyclotronresonance mass spectrometry with direct infusion viaelectrospray ionization to rapidly measure the amino acidisotopomer distribution in a biomass hydrolysate of thesoil bacterium Desulfovibrio vulgaris Hildenborough.By applying high front-end resolution for the precursorion selection followed by sustained off-resonance irradiation collision-induced dissociation, it was possible todetermine exactly and unambiguously the specific locations of the labeled atoms in the amino acids, whichusually requires a combination of 2-D ¹³C NMR spectroscopy and GC/MS. This method should be generallyapplicable to all biomass samples and will allow moreaccurate determination of metabolic fluxes with less workand less sample.