Protein digestion and phosphopeptide enrichment on a glass microchip.

摘要: This work describes an integrated glass microdevice for proteomics, which directly couples proteolysis with affinity selection. Initial results standard phosphopeptide fragments from β-casein in peptide mixtures showed selective capture of the phosphorylated using immobilized metal chromatography (IMAC) beads packed into a microchannel. Complete selectivity was seen angiotensin, only form. On-chip proteolysis, trypsin separate channel, coupled to and devices evaluated β-casein. Captured eluted were analyzed both capillary electrophoresis (CE) liquid chromatography/mass spectrometry (cLC/MS). The show fragments, but incomplete digestion protein apparent multiple peaks CE separations. MS analysis indicated bias on IMAC column tetraphosphorylated fragment over monophosphorylated fragment. Application serum fraction material; however, non-specific binding evident. Additional will be required fully optimize this system, represents novel sample preparation method, incorporating on-line proteomic applications.