Antiparallel arrangement of the helices of vesicle-bound α-synuclein

alpha-Synuclein (alpha S) is the main component of Lewy bodies from Parkinson's disease. That alpha S binds to membranes is known, but the conformation it adopts is still unclear. Pulsed EPR on doubly spin-labeled variants of alpha S sheds light on the most likely structure. For alpha S bound to vesicles large enough to accommodate also the extended conformation, an antiparallel helix conformation is found. This suggests that the bent structure shown is the preferred conformation of alpha S on membranes.