Figure 3.

Solubility, C_e (diamonds), and threshold concentration, $C_{1\beta }$ (crosses), of fibrils of different compositions, as follows. (a) Extended β-strands of length 9, 10, and 11 amino acids. The corresponding values for the dimensionless surface energies are ${\psi }_{\text{h}}=0.9$, 1, and 1.1 and $\psi =9.9$, 11, and 12.1 for strand lengths of 9, 10, and 11, respectively. (b) Extended β-strands and β-strands in a hairpin conformation. The corresponding surface energies are $\psi =11$ (for both) and ${\psi }_{\text{h}}=1$ (extended) or 0.5 (hairpin). (c) Extended β-strands in a parallel and an antiparallel arrangement. The corresponding surface energies are ${\psi }_{\text{h}}=1$ (for both) and $\psi =10$ (antiparallel) or 11 (parallel). (d) Extended β-strands with asymmetric hydrophobic surfaces between β-sheets. The corresponding values for the dimensionless surface energies are ${\psi }_{\text{s}}=1$ (for all) and $\psi =11$, 10.75 and ${\psi }_{\text{w}}=1$, 0.5 for the symmetric and the asymmetric hydrophobic surfaces, respectively. For all compositions shown, the solid red and black lines are obtained from Eqs. 14 and 16, respectively. To see this figure in color, go online.