Figure 2: Cleavage and aggregation of mutant htt exon1.

(a) SDS–PAGE gels showing time-dependent factor Xa cleavage at 22 °C. (b,c) Fibril width derived from negative-stain TEM on the mature fibrils formed at 37 °C (597 measurements over 99 fibrils) and 22 °C (219 measurements over 73 fibrils). (d) Second-derivative FTIR of htt exon1 fibrils formed at 37 °C and (e) 22 °C, for fibrils dispersed in either H2O or D2O. The coloured arrows mark the most notable differences between the fibril types. (f) Reference data on fibrillar K2Q31K2, HNTF (httNTQ30P10K2) fibrils, and aggregated α-helical httNT in PBS buffer, adapted with permission from ref. 13, Copyright 2011 American Chemical Society. (g) Resonance frequencies of different secondary structure elements.