SR M52

The project is concerned with the evaluation of the potentialities of synchrotron radiation in the vacuum ultra violet (VUV) for tandem mass spectrometry (MS/MS). There is clear need for more efficient activation methods in MS/MS. We propose to couple an ion trap mass spectrometer with VUV bealines at the SOLEIL synchrotron radiation facility to perform photon activation of stored ions. Because photoabsorption is a resonant process, all its energy is transferred to the target. Hence, it is a natural way to highly activation ion. The task is challenging but recent developments have demonstrated the feasibility of performing ionisation of stored ions. We believe that the study of the spectroscopy of protein and peptide ions will reveal particularly useful in tandem mass spectrometry. Especially, the nature and decay of highly excited states will be probed for fast dissociation channels. Family of protein, such as proline rich proteins, is difficult to analyse by mass spectormetry. These proteins for example do not fully profit the special feature of electron capture dissociation. Our aim is to complement and provide alternative activation methods to tackle these systems. Moreover, the photochemistry of small ligand molecules in non-covalent interaction with proteins could be used to derive more precisely where the interaction occurs. Finally, the isolated situation of the stored ions makes possible to study some of their spectral properties in an unprecedented range. Especially, we will search for circular dichroic (CD) effect in the fragmentation mass spectra. Correlation of such a CD with gas phase structure could lead to new method for structural determination.