Stabilization of gas-phase noncovalent macromolecular complexes in electrospray mass spectrometry using aqueous triethylammonium bicarbonate buffer.

The use of triethylammonium bicarbonate (TEAB) solution in electrospray mass spectrometry proved to be a very efficient way for studying proteins or noncovalent protein complexes under "nondenaturing" conditions. The low charge states observed in the mass spectra improve the separation of ions arising from macromolecular species of close masses. Moreover, the multiply charged ions generated in a TEAB solution are significantly more stable than those formed under more conventional conditions (for example, with ammonium bicarbonate or acetate solution). The analytical interest of TEAB for the analysis of macromolecular species that can easily dissociate in the gas phase, such as hemoglobin or other macromolecular noncovalent complexes, is demonstrated.