title: Comparison of protein enrichment strategies for proteome analysis of plasma.
abstract: Efforts to discover protein biomarkers in plasma are hampered by the high abundance of few proteins, which interfere with the detection of low-abundant proteins. Different commercially available protein-partitioning products were tested for their ability to lower the detection limit of proteins in 2-D gels. Immuno-depletion using polyclonal antibodies raised against the proteins of highest abundance (Seppro IgY14 System) was compared with a two-step immuno-depletion strategy, where depletion with the Seppro IgY14 column was followed by depletion with the Seppro IgY-SuperMix system. The third strategy tested was protein pre-fractionation using the ProteoMiner kit, where proteins compete for binding sites on bead-bound peptide hexamers with different binding properties. The pre-fractionated protein samples were analyzed using 2-DE, which revealed stunning differences in protein patterns. However, detectable protein spots in the different plasma fractions contained exclusively high-abundant proteins normally present in plasma at concentrations between 1 microg and 40 mg/mL.
authors.affiliation: Pfizer Global Research and Development, Pfizer Inc, Ann Arbor, MI, USA. julia.bandow@rub.de
authors.forename: Julia E
authors.initials: JE
authors.lastname: Bandow
mesh_terms: D015415:Biomarkers / Q000032:analysis / Q000378:metabolism; D001798:Blood Proteins / Q000032:analysis / Q000145:classification / Q000302:isolation & purification* / Q000378:metabolism; D004492:Edetic Acid; D015180:Electrophoresis, Gel, Two-Dimensional / Q000379:methods*; D006801:Humans; D007163:Immunosorbent Techniques; D020543:Proteome / Q000032:analysis*; D040901:Proteomics / Q000379:methods*
chemical_list: D015415:Biomarkers; D001798:Blood Proteins; D020543:Proteome; D004492:Edetic Acid