Fig. 2.

PDS-derived distance distribution for WT alpha-synuclein and three Parkinson’s linked mutants, A30P, E46K, and A53T, doubly spin-labeled at positions 24 and 72, illustrating the presence of two subensembles, one more compact with an average distance around 3.7 nm and one more extended with an average distance of around 5.7 nm (12). The distributions could be reasonably fit as a pair of Gaussians (dashed red lines), allowing for an estimate of their relative populations. While compact conformations can be directly inferred from PRE data such as those in Fig. 1, extended conformations are difficult to detect using PRE approaches.