Fig. 21.
Summary of the model proposed in Bromley et al.50 for the assembly of SAF-type peptide fibers. (A) The proposed assembly mechanism proceeds from an initially unfolded state (a), through dimerization (b), and nucleation (d) steps to form a species that first grows in three dimensions (f) before ending with a species that grows by extension only. Several other possible paths are also shown, but these are found to be not present in this system. (B) The model predicts that control of fiber length should be possible through “seeding”. Figures (i–iv) show representative fluorescence micrographs of SAF samples seeded with varying concentration of seeds. (v) Length distribution of fibers in samples seeded with 10% (black bars) and 1% (gray bars) preformed fibers. (vi) Cumulative length distributions for the four samples imaged, 10% (solid, black), 5% (dashed, black), 2% (dash-dot, black), and 1% (solid, gray).
Reproduced with permission from Bromley et al.50 copyright Elsevier (2009).