PhD project - France

PhD project 5

Probing the Conformational stability of Proteins from solution to the gas phase by combining Lasers to Mass Spectrometry and Ion Mobility

Protein misfolding can lead to aggregation (e.g. in neurodegenerative diseases), and is also a quality control issue in the frame of therapeutic applications of recombinant proteins. However, even the finest Ion Mobility (IMS) setups cannot resolve subtle changes in protein structures. Monitoring protein unfolding, especially through collision-induced unfolding (CIU) is a popular way to tackle this problem, as the unfolding pathway can be dramatically affected by the initial structure. CIU nevertheless lacks specificity and its robustness still needs to be improved. This PhD project will focus on the exploration of new methods to explore the conformational stability and the unfolding pathways of proteins. One direction will consist in using laser excitation in order to better control the unfolding process via local energy deposition on chromophores. Different light sources will be used in order to find the optimal irradiation conditions. Moreover, these experiments will be rationalized through comparison with CIU and thermally-induced unfolding, either in-source of in the gas phase. The PhD candidate will benefit from the unique experimental platform developed in Lyon, including a tandem-IMS-MS instrument and different light-sources already coupled to MS instruments. This project also includes additional secondments within the SPIDocs consortium focusing on protein production (USI, Germany), and the implementation of laser sources in native FTICR-MS instruments (IMIC, Prague, and MSvision, Netherlands). Moreover, this work will also be done in close collaboration with the molecular modelling group of the consortium, in Uppsala.