Fig. 5.

Asymmetric charge distribution can yield anomalous salt dependence. (a and b) Cartoon illustrating what incoming α-syn monomers in solution sense. In the case of membrane-bound α-syn or α-syn in fibrils, it has been suggested that α-syn negative C-terminal tails are sticking out into solution decorating the vesicles and fibrils. The positive N-terminus of α-syn leads to preferential orientation of the monomer relative to the negatively charged surfaces due to attractive electrostatic interactions dominating at low ionic strength (a). At high ionic strength (b) the orientational preference is reduced. Examples of systems showing regular (c and d) and anomalous (e–h) salt dependence. The data are from published work in panels d and g (Meisl et al., 2017), e (André et al., 2006), f (da Silva et al., 2005), c (Linse et al., 1991) and from this work in panel h.