Proc. Natl Acad. Sci. USA 112, 9524–9529 (2015)

Credit: NAS

Because of its association with various neurodegenerative disorders, much is known about the formation mechanism and accumulation, in organs, of insoluble fibrous aggregates of misfolded proteins. Yet less attention has been paid to the dynamic properties of these amyloid fibrils. By imaging the deflection of arrays of deformable microcantilevers surrounding radially growing amyloid structures in a microfluidic device, Therese Herling et al. have now measured the forces generated by amyloid growth. The researchers found that the force levels associated with the growth of a single amyloid filament are comparable to those of polymers that have naturally evolved to generate force, such as actin filaments and microtubules, and that the power density released by amyloid growth is comparable to that of high-performance polymeric microactuators. Amyloid structures can thus be considered as force-generating materials (their formation is energetically favourable), and could make for powerful microactuators in solution (notwithstanding the persistence of the fibrils under physiological conditions).