title: Modified method for determination of sulfur metabolites in plant tissues by stable isotope dilution-based liquid chromatography-electrospray ionization-tandem mass spectrometry.
abstract: A wide variety of sulfur metabolites play important roles in plant functions. We have developed a precise and sensitive method for the simultaneous measurement of several sulfur metabolites based on liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) and (34)S metabolic labeling of sulfur-containing metabolites in Arabidopsis thaliana seedlings. However, some sulfur metabolites were unstable during the extraction procedure. Our proposed method does not allow for the detection of the important sulfur metabolite homocysteine because of its instability during sample extraction. Stable isotope-labeled sulfur metabolites of A. thaliana shoot were extracted and utilized as internal standards for quantification of sulfur metabolites with LC-MS/MS using S-adenosylmethionine (SAM), S-adenosylhomocysteine (SAH), methionine (Met), glutathione (GSH), and glutathione disulfide (GSSG) as example metabolites. These metabolites were detected using electrospray ionization in positive mode. Standard curves were linear (r(2)>0.99) over a range of concentrations (SAM 0.01-2.0μM, SAH 0.002-0.10μM, Met 0.05-4.0μM, GSH 0.17-20.0μM, GSSG 0.07-20.0μM), with limits of detection for SAM, SAH, Met, GSH, and GSSG of 0.83, 0.67, 10, 0.56, and 1.1nM, respectively; and the within-run and between-run coefficients of variation based on quality control samples were less than 8%.
authors.affiliation: Department of Applied Physics and Chemistry, University of Taipei, Taipei 10048, Taiwan.
authors.forename: Ya-Lan
authors.initials: YL
authors.lastname: Chang
authors.forename: Chin-Lin
authors.initials: CL
authors.lastname: Hsieh
authors.forename: Yao-Moan
authors.initials: YM
authors.lastname: Huang
authors.forename: Wen-Liang
authors.initials: WL
authors.lastname: Chiou
authors.forename: Yueh-Hsiung
authors.initials: YH
authors.lastname: Kuo
authors.forename: Mei-Hwei
authors.initials: MH
authors.lastname: Tseng
mesh_terms: D017360:Arabidopsis / Q000737:chemistry* / Q000378:metabolism*; D002853:Chromatography, Liquid; D007201:Indicator Dilution Techniques; D015394:Molecular Structure; D021241:Spectrometry, Mass, Electrospray Ionization; D013455:Sulfur / Q000032:analysis* / Q000378:metabolism*; D013460:Sulfur Isotopes; D053719:Tandem Mass Spectrometry
chemical_list: D013460:Sulfur Isotopes; D013455:Sulfur
keywords: (34)S metabolic labeling; LC–MS/MS; Sulfur metabolites