Biomarkers as a Part of Serum Protein Interactome

During the past decade intensive studies were undertaken to discover specific proteins, biomarkers, which could be used in clinical practice to diagnose disease and to follow the progress of medical treatment [1,2]. In most of these studies human blood serum was used as the predominant source for biomarker discovery. This very complex biofluid contains many thousands of proteins representing nearly all the protein families present in the body as blood vessels come into contact with all organs and tissues. The most abundant proteins – albumin, immunoglobulins, transferrin and several others comprise more than 90% of the serum proteome. Intact cell proteins and their fragments are present but only in low abundance and identifying specific biomarkers within these minor fractions is of particular value. Therefore, the methods used to discover biomarkers must not only be specific but very sensitive as well.