Disulfide proteomics for identification of extracellular or secreted proteins.

摘要: The combination of SDS-PAGE and MS is one the most powerful perhaps frequently used gel-based proteomics approaches in protein identification. However, drawback this method that separation takes place under denaturing reducing (R) conditions as a consequence, all proteins with identical apparent molecular mass (Mr) will run together. Therefore, low-abundant may not be easily identified. Another way investigating by analyzing subproteomes from total proteome such phosphoproteomics, glycoproteomics, or disulfide proteomics. Here, we took advantage property secreted to form bridges investigated disulfide-linked proteins, using nonreducing (NR) conditions. We separated sera normal subjects patients various diseases conditions, followed LC-MS/MS analysis. Although did see any detectable difference between SDS-PAGE(R), could identify (NR). analysis correctly identified haptoglobin (Hp), usually found heterotetramer heteropolymer. Western blotting NR R anti-Hp antibodies confirmed experiments further upon reduction, Hp heterotetramers polymers were no longer polymers. These data suggest simply separating samples on SDS-PAGEunder different, new subset can revealed then