Conformational Ensembles from Experimental Data and Computer Simulations

Conformational Ensembles from Experimental Data and Computer Simulations

Poster Abstracts

101-POS Board 21 Conformational Ensembles of α-synuclein in the Different Conformational States Studied by DNP-Enhanced NMR at Low Temperature Boran Uluca 1,2 , Hamed Shaykhalishahi 1,2 , Dusan Petrovic 1 , Thibault Viennet 1,2 , Franziska Weirich 1,2 , Aysenur Guenuelalan 1 , Birgit Strodel 1,2 , Manuel Etzkorn 1,2 , Wolfgang Hoyer 1,2 , Henrike Heise 1,2 . 1 Forschungszentrum, Jülich, Germany, 2 Heinrich-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].

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