專題：Nature報導
通過測量蛋白版本數量進行的絕對蛋白定量分析，有可能為生物學過程提供重要信息，但除了釀酒酵母的特例外，此前利用標準蛋白質組程序尚未證明這種可能性。
現在，以鉤端螺旋體病病原體「腎臟鉤端螺旋體」作為第一個目標，一種新的質譜方法被用來確定一個蛋白質組中相當大一部分的絕對蛋白質豐度，而該方法所依據的策略應可普遍應用於很多其他的生物學體系。該研究的結果反映了「腎臟鉤端螺旋體」是怎樣在總蛋白版本數量保持不變的情況下通過調整蛋白質組的動態平衡來適應環境變化的。（生物谷Bioon.com）
生物谷推薦原始出處：
Nature 460, 762-765 (6 August 2009) | doi:10.1038/nature08184
Proteome-wide cellular protein concentrations of the human pathogen Leptospira interrogans
Johan Malmstr?m1,5, Martin Beck1,5, Alexander Schmidt1,2, Vinzenz Lange1,2, Eric W. Deutsch3 & Ruedi Aebersold1,2,3,4
1 Institute of Molecular Systems Biology, ETH Zurich (Swiss Federal Institute of Technology), Wolfgang Pauli-Strasse 16, CH-8093 Zurich, Switzerland
2 Competence Center for Systems Physiology and Metabolic Diseases, CH-8093 Zurich, Switzerland
3 Institute for Systems Biology, 1441 North 34th Street, Seattle, Washington 98103-8904, USA
4 Faculty of Science, University of Zurich, CH-8057 Zurich, Switzerland
5 These authors contributed equally to this work.
Mass-spectrometry-based methods for relative proteome quantification have broadly affected life science research. However, important research directions, particularly those involving mathematical modelling and simulation of biological processes, also critically depend on absolutely quantitative data—that is, knowledge of the concentration of the expressed proteins as a function of cellular state. Until now, absolute protein concentration measurements of a considerable fraction of the proteome (73%) have only been derived from genetically altered Saccharomyces cerevisiae cells1, a technique that is not directly portable from yeast to other species. Here we present a mass-spectrometry-based strategy to determine the absolute quantity, that is, the average number of protein copies per cell in a cell population, for a large fraction of the proteome in genetically unperturbed cells. Applying the technology to the human pathogen Leptospira interrogans, a spirochete responsible for leptospirosis2, we generated an absolute protein abundance scale for 83% of the mass-spectrometry-detectable proteome, from cells at different states. Taking advantage of the unique cellular dimensions of L. interrogans, we used cryo-electron tomography morphological measurements to verify, at the single-cell level, the average absolute abundance values of selected proteins determined by mass spectrometry on a population of cells. Because the strategy is relatively fast and applicable to any cell type, we expect that it will become a cornerstone of quantitative biology and systems biology.