The field of native mass spectrometry has advanced significantly over the past several years. Integration of a powerful online separation can advance the field of native mass spectrometry even further. Capillary Electrophoresis (CE), coupled via ESI, is a natural fit for native mass spec analysis because it can be performed in native solvent conditions without concern for interactions with a chromatographic stationary phase. Here we highlight the unique capabilities of a fully integrated microfluidic CE-ESI platform for native protein analysis by demonstrating the high-resolution separation of charge variants of a monoclonal antibody along with two different examples of native protein complex analysis.
- The high efficiency Native ZipChip separation of monoclonal antibodies combined with the high resolution and mass accuracy of mass spectrometers enables acidic variants, such as deamidations, to be clearly identified at the intact level.
- The analysis of native hemoglobin from whole blood shows how the electrophoretic separation can produce clean mass spectra from “dirty” samples and preserve the native structure of very fragile native protein complexes.
- For some complexes CE separation between different proteoforms and multimers can be achieved.