Mechanical unfolding and refolding of proteins: An off-lattice model study- art. no. 021905

Using an off-lattice model, we investigate the response of a protein molecu le to external stretching and release. In particular we study the passive f orce in a protein as a function of the extension of the protein. These forc e-extension curves exhibit hysteresis loops, whose areas increase with the pulling rate and decrease with thermal noise. Most of these results seem to be appropriately described by a cusp catastrophe.