Fig. 10. Stress–strain data for individual fibrillin microfibrils, reproduced from Sherratt et al. (2003). The diamond is their data point, and the solid line their linear interpretation of the mechanical behaviour. The broken curve is another valid interpolation, suggested by the molecular structure of fibrillin (Sherratt et al., 2003), shown in the inset (reproduced with permission from Elsevier). The initial toe region of the J-shaped curve corresponds to molecular unfolding of flexible parts of the fibrillin protein, while the final, much higher stiffness region probably arises from the deformation of rigid, globular domains in the protein.