Comment on the mechanical properties of the amyloid fibre, poly(ValGlyGlyLeuGly), obtained by a novel AFM methodology

Poly(ValGlyGlyLeuGly) is an elastin-like polypeptide belonging to the glycine-rich sequences of elastin [1]. When suspended in water and deposited on silicon wafers, it self-assembles in amyloid-like fibres. These fibres, and those from similar sequences show a remarkable resistance to bending, tending to remain straight across large fields of view, even at bridging points between fibres [2, 3]. We have now confirmed this apparent axial stiffness by measurement of mechanical properties using atomic force microscopy (AFM).