Unusual biophysics of intrinsically disordered proteins

► Intrinsically disordered proteins (IDPs) are important members of the protein kingdom. ► They possess remarkable sequential, structural, spatiotemporal, and functional heterogeneity. ► They have rough and relatively flat energy landscapes. ► They might contain foldons, inducible foldons, semi-foldons and non-foldons. ► IDPs can be considered as the “edge of chaos” systems.