Disordered Motifs and Domains in Cell Control
Poster Session I
3-POS Board 3
α-Synuclein D
2
: The Disorderly Disordered Parkinson’s Disease Amyloid
Ashley S. Phillips
1
, Alexandre F. Gomes
2
, Rebecca Beveridge
1
, Jonas Gasparavicious
3
, Jay E.
Gillam
3
, Fabio C. Gozzo
2
, Cait E. MacPhee
3
, Tilo Kunath
4
, Perdita E. Barran
1
.
1
University of Manchester, Manchester, United Kingdom,
2
State University of Campinas, São
Paulo, Brazil,
3
University of Edinburgh, Edinburgh, United Kingdom,
4
MRC Centre for
Regenerative Medicine, University of Edinburgh, Edinburgh, United Kingdom.
Parkinson’s disease is the 2nd most common neurodegenerative disorder worldwide, affecting
approximately 2% of the world population over 65. Current UK spending is ~£3.3billion and
with those aged over 65 predicted to double by 2050, a treatment is quickly becoming of
paramount importance.
α-Synuclein is an amyloidogenic intrinsically disordered protein implicated in Parkinson’s
disease aetiology, whose potential functions range from enzyme regulation to synaptic vesicle
release. α-Synuclein co-exists in conformations ranging from disordered monomers to β-sheet
rich fibrils. Our aim is to unravel the structures of the potentially druggable early aggregation
species using multiple gas phase techniques, to inform a drug discovery process whose
disordered subject limits the use of traditional techniques.
Ion Mobility Mass Spectrometry (IMMS) is a hybrid mass spectrometry based gas phase
electrophoretic technique which generates a rotationally averaged Collision Cross Section (CCS)
for each conformer. Native Mass Spectrometry (MS) and IMMS have the ability to study the
structure and conformational dynamics of complex protein samples.
Under gentle Nano Electrospray Ionisation conditions (nESI) α-Synuclein presents ions, over a
wide charge state range in positive and negative mode, characteristic of its intrinsically
disordered nature. The CCS of α-Synuclein monomers range from ~1000Å
2
to ~3000Å
2
, again
demonstrating its conformational flexibility. nESI also reveals small aggregate populations up to
pentamer.
MS and IMMS highlight the conformational plasticity of α-Synuclein, including its susceptibility
to solution condition modification, genre-defining levels of day-to-day variation and the lack of a
solution phase conformational response following in vitro aggregation. Crosslinking-IMMS has
also been used to directly sample the abundance solution phase conformers. Our results are
compared to established biophysical techniques.
These results highlight the advantages of mass spectrometry-based approaches in determining
transient structural forms and their application to studying the aggregation of amyloidogenic
proteins.
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