Human Serum Proteins Preseparated by Electrophoresis or Chromatography Followed by Tandem Mass Spectrometry

John Marshall,*^† Andy Jankowski, Shirley Furesz, Inga Kireeva, Lisa Barker, Mila Dombrovsky, Weimin Zhu, Kellie Jacks, Leslee Ingratta, Jenny Bruin, Erika Kristensen, Rulin Zhang, Eric Stanton,^‡ Miyoko Takahashi, and George Jackowski^§

Journal of Proteome Research, 2004, 3 (3), pp 364–382

DOI: 10.1021/pr034039p

Publication Date (Web): January 15, 2004

Copyright © 2004 American Chemical Society

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Electrophoretic and chromatographic sample preparations were compared and together detected the presence of some 600 types of protein products in human serum. Proteins from crude serum preseparated by ionic electrophoresis, chromatography, or a combination of both were analyzed. Proteins were digested with trypsin or chymotrypsin. Naturally occurring peptides were also collected by reversed-phase chromatography. The resulting peptides were identified by tandem mass spectrometry. The peptides were either desorbed by a laser from a metal chip into a quadrupole-time-of-flight mass spectrometer or ionized as an electro-spray from reversed-phase chromatography via a metal needle under voltage into an ion-trap mass spectrometer. All of the commonly known proteins associated with serum were detected, and the two mass spectrometers agreed on the identity of abundant serum proteins. Preseparation of serum proteins prior to digestion markedly enhanced the capacity to detect un-common proteins from blood. Electrophoretic- and chromatography-based experiments were found to be complementary. Many novel cellular proteins not previously associated with serum were recorded.

Keywords: human • serum • protein • proteome • electrophoresis • chromatography • tandem • mass spectrometer