Template-controlled conformational patterns of insulin fibrillar self-assembly reflect history of solvation of the amyloid nuclei.

In the presence of ethanol, insulin forms amyloid morphologically distinct from the ambient specimen. Due to stability of fibrils and the autocatalytic character of the process, the two amyloid templates, when seeded, replicate the initial morphologies (and inter-beta-strand hydrogen bonding patterns) regardless of the environmental biases, such as the cosolvent presence. Such "templated memory" effect is advantageous in synthesizing structurally uniform protein nanofibrils under conditions favoring alternative "wild" forms. This also appears to parallel "prion strains" phenomenon, suggesting that "strains" may reflect a generic trait in all amyloids including those not associated with disease.