title: Tandem affinity monolithic microcolumns with immobilized protein A, protein G', and antibodies for depletion of high abundance proteins from serum samples: integrated microcolumn-based fluidic system for simultaneous depletion and tryptic digestion.
abstract: Affinity monolithic microcolumns with immobilized affinity ligands including protein A, protein G' and polyclonal antibodies were developed for the microscale depletion of the top eight most abundant proteins in human serum. These various affinity microcolumns were evaluated for their sample loading capacities with the standard protein substrates. In general, the sample loading capacity of protein A and protein G' was about 7-25 fold higher than that of the antibody-based affinity columns. The macroporous nature of the monolithic columns, which offers high permeability in pressure-driven flow, allowed the design of long tandem affinity columns for the simultaneous depletion of the top eight most abundant proteins in a single run. The tandem format could be extended to include additional affinity monolithic columns to deplete other proteins for which specific antibodies are available without running into high inlet pressure. Furthermore, the tandem affinity columns were integrated with immobilized trypsin monolithic columns to achieve the simultaneous depletion and digestion of proteins. The various formats investigated in this study could be down scaled to achieve nanoLC or up scaled to perform conventional HPLC depending on the size of the proteomic samples.
authors.affiliation: Department of Chemistry, Oklahoma State University, Stillwater, Oklahoma 74078-3071, USA.
authors.forename: Yazen
authors.initials: Y
authors.lastname: Jmeian
authors.forename: Ziad
authors.initials: Z
authors.lastname: El Rassi
mesh_terms: D000818:Animals; D000906:Antibodies; D001426:Bacterial Proteins; D001798:Blood Proteins / Q000276:immunology / Q000302:isolation & purification* / Q000378:metabolism; D002846:Chromatography, Affinity / Q000379:methods*; D006801:Humans; D046210:Microfluidic Analytical Techniques / Q000379:methods*; D040901:Proteomics / Q000295:instrumentation / Q000379:methods; D013205:Staphylococcal Protein A; D014357:Trypsin / Q000378:metabolism
chemical_list: D000906:Antibodies; D001426:Bacterial Proteins; D001798:Blood Proteins; C034284:IgG Fc-binding protein, Streptococcus; D013205:Staphylococcal Protein A; D014357:Trypsin