Conformational Ensembles from Experimental Data and Computer Simulations

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Conformational Ensembles from Experimental Data
and Computer Simulations Poster Abstracts
138
101-POS Board 21
Conformational Ensembles of α-synuclein in the Different Conformational States Studied
by DNP-Enhanced NMR at Low Temperature
Boran Uluca1,2 , Hamed Shaykhalishahi1,2, Dusan Petrovic1, Thibault Viennet1,2, Franziska
Weirich1,2, Aysenur Guenuelalan1, Birgit Strodel1,2, Manuel Etzkorn1,2, Wolfgang Hoyer1,2,
Henrike Heise 1,2.
1Forschungszentrum, Jülich, Germany, 2Heinrich-Heine-Universität Düsseldorf, Düsseldorf,
Germany.
Dynamic Nuclear Polarization (DNP) overcomes the inherently low sensitivity of magnetic
resonance methods by transferring high spin polarization of unpaired electrons to surrounding
nuclei. Low-temperature Nuclear Magnetic Resonance (NMR) spectra usually suffer from severe
line broadenings due to freezing out different conformations [1]. While this is usually accounted
for as an unwanted side-effect of DNP-NMR, these inhomogeneously broadened lines also
contain valuable information about conformational ensembles of (disordered) proteins.
To study conformational ensembles of intrinsically disordered proteins, both experimental and
computational methods have evolved. For the experiments reported here, we have chosen α-
synuclein as a model protein and the large-scale conformational flexibility is investigated both
DNP-Enhanced NMR and by a molecular dynamics (MD) simulations. We have studied the
conformational ensemble of α-synuclein in frozen solution under different conditions: in the
fully disordered form, in the fibrillated form with flexible ends, and in contact with lipid bilayers
in the form of nanodiscs (in different ratio protein/nanodisc). We could probe the conformational
ensembles of all valine residues in α-synuclein by selectively labeling the sample with [2-13C]-
glucose [2].