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Cyclic Ion Mobility – Collision Activation Experiments Elucidate Protein Behaviour in the Gas-Phase

submitted on 22.01.2020 and posted on 23.01.2020 by Charles Eldrid, Jakub Ujma, Hannah Britt, Tristan Cragnolini, Symeon Kalfas, Dale Cooper-Shepherd, nick tomczyk, Kevin Giles, mike morris, Rehana Akter, Daniel Raleigh, Konstantinos Thalassinos
Elucidating the properties of intrinsically disordered proteins (IDPs) and unfolded and partially folded states of globular proteins is challenging owing to their heterogeneous and dynamic nature. Protein unfolding and misfolding is a key feature of a broad range of debilitating diseases, whilst the conformational propensities of intrinsically disordered proteins can play a significant role in modulating their activity, and the properties of unfolded states of globular proteins modulates their stability and tendency to aggregate. Ion mobility-mass spectrometry (IM-MS) is a powerful method for interrogating these systems, however limits in resolution and the difficulty in probing the energetics of interconversions amongst heterogeneous ensembles are major issues. Herein, using a quadrupole/cyclic-IM/ time-of-flight MS instrument, we show how the combination of precursor mass selection, mobility selection (IMn) and collisional activation (CA) allows the elucidation of complicated gas-phase dynamic behavior. The methodology employed is general and is demonstrated using a classic model globular protein, cytochrome C, and an aggregation-prone IDP, amylin. CA allows investigations of protein conformational dynamics and unfolding in the gas-phase for heterogeneous mixtures, whilst the additional precursor mass selection capability provides high resolution and selectivity, facilitating more in-depth investigation. Understanding protein dynamics in the gas-phase will allow greater insight into protein behaviour and allow application of gas-phase techniques to clinically relevant systems.


Email Address of Submitting Author


University College London


United Kingdom

ORCID For Submitting Author


Declaration of Conflict of Interest

.U., N.T., D.CS., K.G., and M.M. are all employees of Waters Corporation, which manufactures and sells T-wave IM-MS instruments.


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