The use of H/D exchange for secondary structure characterization of supermetallized complexes of ubiquitin with cerium(III)

Resumo

The approach of hydrogen/deuterium exchange combined with ultrahigh resolution mass spectrometry was applied for investigation of conformational changes of supermetallized ubiquitin ions with cerium(III) atoms. The dependencies of the hydrogen/deuterium exchange efficiency on the charge state of ubiquitin ion, the number of associated cerium atoms, as well as on the temperature were obtained. The reaction of hydrogen/deuterium exchange was performed directly in the ionization source according to previously described method. It was found that the number of exchanges is hardly altered under the addition of cerium atoms. This result indirectly suggests that the conformation of small protein supermetallized ions does not significantly change during electrospray ionization.