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 t o 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 solutio n temperatures, a thermal induced denaturation of ubiquitin, in the tempera ture range between 25 and 90 degrees C, was investigated. A single structur e transition of ubiquitin was observed. Heating and unassisted cooling by a ir convection of the sample solution occurs directly inside the nanospray c apillary during the electrospray measurement. Therefore, this new device is also suitable for probing for the reversibility of conformational changes in proteins.