Submitted on May 1, 2006
Revised on October 9, 2006
Accepted on October 9, 2006
Mass spectrometric detection of tissue proteins in plasma
Hui Zhang, Alvin Y. Liu, Paul Loriaux, Bernd Wollscheid, Yong Zhou, Julian D. Watts, and Ruedi Aebersold
Institute for Systems Biology, Seattle, WA 98103
Corresponding Author: hzhang{at}systemsbiology.org
It has long been thought that blood plasma could serve as a window into the state of ones organs in health and disease because tissue-derived proteins represent a significant fraction of the plasma proteome. While substantial technical progress has been made towards the goal of comprehensively analyzing the blood plasma proteome, the basic assumption that proteins derived from a variety of tissues could indeed be detectable in plasma using current proteomic technologies has not been rigorously tested. Here, we provide evidence that such tissue-derived proteins are both present and detectable in plasma via direct mass spectrometric analysis of captured glycopeptides, and thus provide a conceptual basis for plasma protein biomarker discovery and analysis.