Online mass spectrometry of CE (SDS)-separated proteins by two-dimensional capillary electrophoresis.

Online mass spectrometry of CE (SDS)-separated proteins by two-dimensional capillary electrophoresis. Anal Bioanal Chem. 2019 Oct 15;: Authors: Römer J, Montealegre C, Schlecht J, Kiessig S, Moritz B, Neusüß C Abstract Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) is the fundamental technique for protein separation by size. Applying this technology in capillary format, gaining high separation efficiency in a more automated way, is a key technology for size separation of proteins in the biopharmaceutical industry. However, unequivocal identification by online mass spectrometry (MS) is impossible so far, due to strong interference in the electrospray process by SDS and other components of the SDS-MW separation gel buffer. Here, a heart-cut two-dimensional electrophoretic separation system applying an electrically isolated valve with an internal loop of 20 nL is presented. The peak of interest in the CE (SDS) separation is transferred to the CZE-MS, where electrospray-interfering substances of the SDS-MW gel are separated prior to online electrospray ionization mass spectrometry. An online SDS removal strategy for decomplexing the protein-SDS complex is implemented in the second dimension, consisting of the co-injection of organic solvent and cationic surfactant. This online CE (SDS)-CZE-MS system allows MS characterization of proteoforms separated in generic CE (SDS), gaining additional separation in the CZE ...
Source: Analytical and Bioanalytical Chemistry - Category: Chemistry Authors: Tags: Anal Bioanal Chem Source Type: research