Characterization of the low molecular weight human serum proteome

Serum potentially carries an archive of important histo-logical information whose determination could serve to improve early disease detection. The analysis of serum, however, is analytically challenging due to the high dy-namic concentration range of constituent protein/peptide species, necessitating extensive fractionation prior to mass spectrometric analyses. The low molecular weight (LMW) serum proteome is that protein/peptide fraction from which high molecular weight proteins, such as albu-min, immunoglobulins, transferrin, and lipoproteins, have been removed. This LMW fraction is made up of several classes of physiologically important proteins such as cy-tokines, chemokines, peptide hormones, as well as pro-teolytic fragments of larger proteins. Centrifugal ultrafil-tration of serum was used to remove the large constituen