The Barran group has considerable experience in gas-phase ion chemistry and the application and development of mass spectrometry for complex chemical and biological problems. We use solvent free methodologies to provide an understanding of structure function relationships of proteins and peptides at the molecular level, and to use this information to further biomedical research. Our work has a particular focus on disordered and dynamic protein systems, weak interactions, and supramolecular systems. We aim to use mass spectrometry to solve problems that cannot be tackled well by other methods.
Gentle application of nano electrospray to proteins buffered in solution to an appropriate pH allows us to use mass spectrometry to interrogate the gas phase version of their solution conformations. This can be achieved directly with ion mobility mass spectrometry, where we measure the rotationally averaged temperature dependent collision cross section of mass separated ions, or more indirectly with the use of dissociation methods and/or HDX.
Data obtained from both methods provides insight to the structure and stability of the protein, and also detail on its interactions, especially when combined with atomistically resolved data from crystallography and or computational approaches. DT IM-MS is our central technique and one that we are currently developing a new higher resolution instrument for, however we employ several other biophysical methodologies.
The diagram presents variety of molecules that have been analysed on our linear drift tube ion mobility mass spectrometer 'The MoQTOF' as of early 2013. We have determined collision cross sections (CCSs) for systems ranging from molecular knots, supramolecular cages, though variety of peptides and monomeric proteins up to large protein complexes such as antibodies (~150 kDa) and human SAP (~250 kDa)