Figure 5.

(A) Predicted free energy of oligomer formation for ${\ell }_Q$ = 20, 30, and 40 in the presence and absence of N- and C-terminal tails. Increasing the length of the polyQ region or adding the N17 tail results in larger oligomers because the extra length more easily stretches to fill the oligomer core. However, adding the C38 tail adds a repulsive energy that favors smaller oligomers. (B) Changing the polyQ length has an exponential effect on the critical concentration for oligomer formation. The critical concentration drops by more than a factor of 10³ upon changing the ${\ell }_Q$ from 20 to 40. To see this figure in color, go online.