The interplay between metal ions and amyloids plays a significant role not only in the pathogenesis of neurodegenerative disorders such as Alzheimer's and Parkinson's disease but also in the development of application technologies for the synthesis of metal nanomaterials. In this study, we investigate the interplay between amyloids and heavy metal ions using screen-printed electrochemical sensor functionalized with amyloid fibrils. For this purpose, amyloid fibril-functionalized screen-printed electrochemical sensor was devised. Various heavy metal ions (e.g., palladium, mercury, copper, and cadmium) directly reacted with amyloid fibrils at different concentrations. In addition, molecular dynamics simulation was used to compare the individual binding energies between metal ions and amyloids, which was consistent with the results of the electrochemical analysis. We believe that amyloid functionalized electrochemical sensor is helpful to gain insight into the interaction between amyloids and heavy metal ions as well as the development of amyloid-metal ion application techniques.

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Oligomeric and fibrillar amyloids, which cause neurodegenerative diseases, are typically formed through repetitive fracture and elongation processes involving single homogeneous amyloid monomers.

The HET-s prion fibril, which is found in the filamentous fungus Podosporaanserina, exhibits conformational changes due to variations in pH. Here, we explain the effects of changing pH on the conformational changes of fibrils through the fundamental eigenmodes of the fibrils, in particular the torsional and bending modes, using a parameter free elastic network model. In particular, the motion resulting from these fundamental eigenmodes is found to be very similar to the conformational changes stimulated by pH variations as shown in previous experimentalal results. 1 Finally, we calculated the mechanical properties of the triplet prion fibrils to elucidate its variations in the infectious state.

Silk materials are receiving significant attention as base materials for various functional nanomaterials and nanodevices, due to its exceptionally high mechanical properties, biocompatibility, and degradable characteristics. Although crystalline silk regions are composed of various repetitive motifs with differing amino acid sequences, how the effect of humidity works differently on each of the motifs and their structural characteristics remains unclear. We report molecular dynamics (MD) simulations on various silkworm fibroins composed of major motifs (i.e. (GAGAGS), (GAGAGA), and (GAGAGY)) at varying degrees of hydration, and reveal how each major motifs of silk fibroins change at each degrees of hydration using MD simulations and their structural properties in mechanical perspective via steered molecular dynamics simulations. Our results explain what effects humidity can have on nanoscale materials and devices consisting of crystalline silk materials.