Mechanical characterization of prion fibrils using coarse-grained modeling approach in Silico

Prions are self-replicating proteins composed of β-sheet secondary structures that can cause neurodegenerative disorders such as Bovine Spongiform Encephalopathy(also known as mad cow disease), and they also can be found in various kinds of disease such as Alzheimer's diseases and type II diabetes [1]. At the molecular level, prions propagate an amyloid fibril by forming β-sheet structures that are oriented perpendicularly to the fibril axis, and connected through a dense hydrogen-bonding network which makes them stable [1]. Because of the mechanical toughness, understanding the mechanical characteristics of prion protein could play a key role to the development of the pathological treatment for those diseases caused by prion. One of the well-known prion proteins is HET-s protein which appears to have specific biological function in the filamentous fungus Podospora anserine. In this study, we elongated the HET-s(218-289) and characterized the mechanical properties of HET-s. Normal Mode Analysis(NMA) with Elastic Network Model(ENM) are used to predict the possible elastic deformation mode of the HET-s(218-289). ANM(Anisotropic Network Model) and continuous beam model are also used to make the result.