Tabata Tsuyoshi, Sato Toshitaka, Kuromitsu Junro, Oda Yoshiya
Eisai Co., Ltd. Laboratory of Core Technology, Tokodai 5-1-3, Tsukuba, Ibaraki 300-2635, Japan.
Anal Chem. 2007 Nov 15;79(22):8440-5. doi: 10.1021/ac701628m. Epub 2007 Oct 12.
Quantitative proteome analysis has become a versatile tool to understand biological functions. Although stable isotope labeling is the most reliable method for quantitative mass spectrometry, preparation of isotope-labeled compounds is time-consuming and expensive. Simple label-free approaches have been introduced, but intensity-based quantitation without standards is not generally accepted as reliable, especially for small molecules. We have developed a novel label-free quantitative proteome analysis using pseudo internal standards (PISs). This idea was derived from northern blotting analysis, in which housekeeping genes are used as standards to normalize and compare target gene expression levels in different samples. In many proteomics studies, most proteins do not change their expression levels under different conditions, and therefore, these proteins can be employed as pseudo internal standards. This new approach is simple and does not require additional standards or labeling reagents. The PIS method represents a novel approach for mass spectrometry-based comprehensive quantitatitation and may also be applicable to quantitative metabolome analysis.
定量蛋白质组分析已成为理解生物学功能的通用工具。尽管稳定同位素标记是定量质谱分析最可靠的方法，但同位素标记化合物的制备既耗时又昂贵。已引入了简单的无标记方法，但基于强度且无标准品的定量方法一般不被认为可靠，尤其是对于小分子。我们开发了一种使用伪内标（PIS）的新型无标记定量蛋白质组分析方法。这个想法源自Northern印迹分析，其中管家基因用作标准品来标准化和比较不同样品中靶基因的表达水平。在许多蛋白质组学研究中，大多数蛋白质在不同条件下其表达水平不会改变，因此，这些蛋白质可作为伪内标。这种新方法简单，不需要额外的标准品或标记试剂。PIS方法代表了一种基于质谱的全面定量的新方法，也可能适用于定量代谢组分析。
