Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Wertheim cung cấp cho các bạn kiến thức về ngành y đề tài: Comparing cellular proteomes by mass spectrometry. | X Genome Biology Minireview Comparing cellular proteomes by mass spectrometry Florian Frohlich and Tobias C Walther Address Organelle Architecture and Dynamics Max Planck Institute of Biochemistry Am Klopferspitz 18 82152 Martinsried Munich Germany. Correspondence Tobias C Walther. Email twalther@ Abstract Mass spectrometry and cryo-electron tomography together enable the determination of the absolute and relative abundances of proteins and their localization laying the groundwork for comprehensive systems analyses of cells. Biological systems are characterized by the dynamic interplay of their components and to understand how individual parts act together it is crucial to know the composition of a system and how it changes over time. The protein components are of prime interest as they provide structure and carry out many functions in the cell. The transcriptome has been much used as a proxy to infer changes in protein expression as techniques for measuring global RNA levels preceded those for measuring the proteome. However when the levels of an mRNA and its corresponding protein are systematically compared many differences in their abundance emerge resulting in poor quantitative correlation overall between transcriptome and proteome 1-3 . Ways of measuring protein levels directly are therefore highly desirable and breakthroughs in mass spectrometry MS -based proteomics are starting to enable this on a global scale. In experiments recently published in Nature Ruedi Aeber-sold and colleagues Malmstrom et al. 4 combined MS-based measurements of protein abundance in the bacterial pathogen Leptospira interrogans the agent of Weil s disease with imaging by cryo-electron tomography CET of distinct structures of known protein composition such as the flagellar motor in which the precise number and type of the protein subunits can be counted . The CET imaging provided a way of confirming the MS proteinquantitation data. The protein-abundance measurements .
