Mechanical unfolding of DDFLN4 studied by coarse-grained knowledge-based CABS model

Mechanical unfolding of the fourth domain of Distyostelium discoideum filamin ( DDFLN 4) was studied using a CABS – coarse-grained knowledge-based protein model. Our study demonstrates that CABS is capable of reproducing the unfolding free energy landscape of protein unfolding and highlights an important role of non-native interactions in the protein unfolding process. The obtained three peaks in the force-extension profile suggest a four-state picture of DDFLN 4 protein unfolding and correspond reasonably to the results of the all-atom simulation in explicit solvent.