α-Synuclein dimer structures found from computational simulations

Dimer formation is likely the first step in the oligomerization of α-synuclein in Lewy bodies. In order to prevent α-synuclein aggregation, knowledge of the atomistic structures of possible α-synuclein dimers and the interaction affinity between the dimer domains is a necessary prerequisite in the process of rational design of dimerization inhibitors. Using computational methodology, we have investigated several possible α-synuclein dimer structures, focusing on dimers formed from α-helical forms of the protein found when it is membrane-bound, and dimers formed from β-sheet conformations predicted by simulations. Structures and corresponding binding affinities for the interacting monomers in possible α-synuclein dimers, along with properties including the contributions from different interaction energies and the radii of gyration, were found through molecular docking followed by MD simulations and binding-energy calculations. We found that even though α-synuclein is highly charged, hydrophobic contributions play a significant role in stabilizing dimers.