We have studied the effect of loading device such as its stiffness on the mechanical force-driven protein unfolding based on coarse-grained simulation (i.e. Brownian dynamics simulation with coarse-grained model). We have shown that loading device effect has played a vital role on not only the unfolding force but also the unfolding pathway of a protein. Moreover, the loading device effect on protein unfolding force has been elucidated by a theoretical model such as Kramers theory with appropriate free energy landscape. This work was published at Journal of Chemical Physics (for link, click http://link.aip.org/link/?JCP/137/025102).
Figure. The unfolding pathway of a ubiquitin is shown when it is pulled with a soft loading device (a) or a stiff force probe (b).