PDF(Pubmed)
Abstract：
Mass spectrometry has been an essential technique for the investigation of the metabolic pathways of living organisms since its appearance at the beginning of the 20th century. Due to its capability to resolve isotopically labeled species, it can be applied together with stable isotope tracers to reveal the transformation of particular biologically relevant molecules. However, low-resolution techniques, which were used for decades, had limited capabilities for untargeted metabolomics, especially when a large number of compounds are labelled simultaneously. Such untargeted studies may provide new information about metabolism and can be performed with high-resolution mass spectrometry. Here, we demonstrate the capabilities of high-resolution mass spectrometry to obtain insights on the metabolism of a model plant, Lepidium sativum, germinated in D2O and H218O-enriched media. In particular, we demonstrated that in vivo labeling with heavy water helps to identify if a compound is being synthesized at a particular stage of germination or if it originates from seed content, and tandem mass spectrometry allows us to highlight the substructures with incorporated isotope labels. Additionally, we found in vivo labeling useful to distinguish between isomeric compounds with identical fragmentation patterns due to the differences in their formation rates that can be compared by the extent of heavy atom incorporation.
摘要：
自20世纪初出现以来，质谱一直是研究生物体代谢途径的重要技术。由于它能够分辨同位素标记的物种，它可以与稳定的同位素示踪剂一起应用，以揭示特定生物相关分子的转化。然而,低分辨率技术，使用了几十年，非靶向代谢组学的能力有限，尤其是当大量化合物同时被标记时。这样的非靶向研究可以提供关于代谢的新信息,并且可以用高分辨率质谱进行。这里,我们展示了高分辨率质谱的能力，以获得对模型植物代谢的见解，Lepidiumsativum,在D2O和H218O富集的培养基中发芽。特别是,我们证明，在体内标记与重水有助于确定，如果一个化合物是合成在发芽的特定阶段，或如果它起源于种子内容，和串联质谱使我们能够突出结合同位素标记的子结构。此外,我们发现体内标记可用于区分具有相同片段化模式的异构化合物，因为它们的形成速率不同，可以通过重原子掺入的程度进行比较。
