Novel Native Mass Spectrometry and Ion Mobility Approaches for the Characterization of Membrane Proteins and Pores
16 January 2020
Campus Middelheim, A.143 - Middelheimlaan 1 - 2020 Antwerpen (route: UAntwerpen, Campus Middelheim
Organization / co-organization:
Department of Chemistry
Jeroen van Dyck
Frank Sobott & Dirk Snyders
PhD defence Jeroen van Dyck - Faculty of Science, Department of Chemistry
Native mass spectrometry has shown over the past years to be a very useful tool in the investigation of membrane proteins and pores, which provides additional information next to the conventional structural techniques. This information concerns for example the stoichiometry of complexes and structural information. In recent years native mass spectrometry has shown to be very useful for the investigation of large noncovalent, mainly globular structures. In this thesis different projects are presented and discussed showing the versatility of native mass spectrometry; including membrane associated proteins and nanopores build from custom designed DNA strands. To investigate each of the different projects ion mobility and mass spectrometric techniques were used. This also includes the methods of sample preparation required to transfer the samples into the gas phase without disturbing the complexes formed significantly.
The BAX protein revealed to behave differently, when different detergents were present in solution above the critical micelle concentration or when binding the directly activating molecule BAM-7. Ion mobility and mass spectrometry show that it forms oligomers and conformational changes.
Native mass spectrometry turned out to be very useful in the investigation of lipid interactions with membrane proteins. This was shown by MgtA membrane protein revealing a very specific binding of lipids. Native MS has shown to be very useful for observing of specifically bound lipids even when high concentrations of other lipid were present.
DNA origami is a term used for artificial designed nano-structures from DNA building blocks. Within this thesis the formation of such a DNA nano-structure was investigated concerning the formation of a DNA nanopore. This pore is formed from different DNA strands which should only fit together in one possible manner. Using ion mobility mass spectrometry it was shown that the salt concentration, in the form of ammonium acetate, has a profound influence on the actual form of the hexameric pore.