Molecular inscription of environmental information into protein suprastructures: temperature effects on unit assembly of α-synuclein oligomers into polymorphic amyloid fibrils

Molecular-level storage of environmental information in biological structures in tangible forms, and their subsequent transfer to the next generation, has been studied using the phenomenon of amyloidogenesis, which defines a biochemical condition generating highly ordered protein aggregates known as amyloid fibrils. α-Synuclein oligomers shown to experience unit assembly as the formation of amyloid fibrils were used in the present study as an environment-sensing agent. With temperature varying in 2°C intervals between 37°C and 43°C, the oligomeric unit assembly led to fibrillar polymorphism from a straight to a curly appearance, as assessed using TEM and small-angle neutron scattering; the different effects on the secondary structures were evaluated using attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy. The resulting diversified amyloid fibrils, which have distinctive molecular characteristics, were shown to be inherited by the next generation through the self-propagating property of amyloidogenesis. Storage of intangible temperature information in the diversified protein suprastructures and perpetuation of the stored information in the form of polymorphic amyloid fibrils could represent molecular inscription of environmental information into biological systems; this could further extend our understanding of any physiological/pathological significance of amyloidogenic polymorphism and be utilized in the area of nanobiotechnology to process various external signals. Abbreviations: AD, Alzheimer’s disease; ANS, 8-anilino-1-naphthalenesulfonic acid; ATR-FTIR, attenuated total reflectance Fourier-transform infrared; PD, Parkinson’s disease; SANS, small-angle neutron scattering; Thio-T, thioflavin-T