Cystine plug and other novel mechanisms of large mechanical stability in   dimeric proteins
  We identify three dimeric proteins whose mechanostability is anisotropic and should exceed 1 nN along some directions. They come with distinct mechanical clamps: shear-based, involving a cystine slipknot, and due to dragging of a cystine plug through a cystine ring. The latter two mechanisms are topological in nature and the cystine plug mechanism has not yet been discussed but it turns out to provide the largest resistance to stretching. Its possible applications in elastomers are discussed. 
Mateusz Sikora and Marek Cieplak
q-bio.BM physics.bio-ph