FIGURE 3.
The effect of temperature on the force dependence of polyubiquitin unfolding. Semilogarithmic plot of the rate of unfolding of ubiquitin, k(F, T), as a function of the pulling force at: 5 °C (triangles), 15 °C (inverted triangles), 25 °C (circles), 35 °C (diamonds), and 45 °C (squares). The solid colored lines in each case represent fits to the Arrhenius/Bell term (Equation 3 under “Results”) to the experimental data. From these fits, we obtained the associated Δx and k0 value for each probed temperature. The range of forces probed for each particular temperature is chosen such that they do not compromise the measurement due to limited feedback response at fast unfolding rates and cantilever drift for slow unfolding kinetics.