Evaluation of heat-induced conformational changes in proteins by nanoelectrospray Fourier transform ion cyclotron resonance mass spectrometry

The characterization of heat-induced conformational changes of proteins by nanoelectrospray mass spectrometry is shown. The used device is the first to make a simple and effective investigation of the denaturation of proteins possible using minimum sample consumption, as enabled by nanoelectrospray mass spectrometry, As indicated by average charge states at several solution temperatures, a thermal induced denaturation of ubiquitin, in the temperature range between 25 and 90 degrees C, was investigated. A single structure transition of ubiquitin was observed. Heating and unassisted cooling by air convection of the sample solution occurs directly inside the nanospray capillary during the electrospray measurement. Therefore, this new device is also suitable for probing for the reversibility of conformational changes in proteins.