Fig. 6.
Representative structures of proteins involved in disease-related amyloid fibril formation. The polypeptides are coloured according to the aggregation tendency of their amino acid sequences predicted using the algorithm TANGO [187]. Sequences shown in blue are predicted to have no β-aggregation propensity, while polypeptide stretches coloured in yellow, orange and red indicate an increasing propensity to aggregate. Notably, the peptide structures were obtained in the presence of fluoroalcohols (calcitonin and Aβ1–42) or SDS micelles (amylin), and these sequences might be substantially less ordered in the absence of these additives. Note also that for insulin, amylin and calcitonin, the pro-peptides as well as the mature sequences have been implicated as potentially amyloidogenic [225–227].