posted on 2023-01-12, 16:35authored byAgathe Depraz Depland, Iuliia Stroganova, Christopher A. Wootton, Anouk M. Rijs
Ion mobility mass spectrometry (IM-MS) has proven to
be an excellent
method to characterize the structure of amyloidogenic protein and
peptide aggregates, which are formed in coincidence with the development
of neurodegenerative diseases. However, it remains a challenge to
obtain detailed structural information on all conformational intermediates,
originating from the early onset of those pathologies, due to their
complex and heterogeneous environment. One way to enhance the insights
and the identification of these early stage oligomers is by employing
high resolution ion mobility mass spectrometry experiments. This would
allow us to enhance the mobility separation and MS characterization.
Trapped ion mobility spectrometry (TIMS) is an ion mobility technique
known for its inherently high resolution and has successfully been
applied to the analysis of protein conformations among others. To
obtain conformational information on fragile peptide aggregates, the
instrumental parameters of the TIMS-Quadrupole-Time-of-Flight mass
spectrometer (TIMS-qToF-MS) have to be optimized to allow the study
of intact aggregates and ensure their transmission toward the detector.
Here, we investigate the suitability and application of TIMS to probe
the aggregation process, targeting the well-characterized M307-N319
peptide segment of the TDP-43 protein, which is involved in the development
of amyotrophic lateral sclerosis. By studying the influence of key
parameters over the full mass spectrometer, such as source temperature,
applied voltages or RFs among others, we demonstrate that by using
an optimized instrumental method TIMS can be used to probe peptide
aggregation.