Figure 8.

The ultimate tensile strength with respect to the natural log of the pulling speed is plotted for (a) RiAFP (purple) and (b) SBAFP (green). The errors are calculated using the SD of the maximum forces at each speed. For each protein, we note two distinct linear regimes, to which we fit two lines (black). For RiAFP, the lines are given by ${\text{UTS}}_{slow}=0.045\text{ln}\left(v\right)+0.367$ and ${\text{UTS}}_{fast}=0.275\text{ln}\left(v\right)-0.369$. For SBAFP, the lines are given by ${\text{UTS}}_{slow}=0.029\text{ln}\left(v\right)+0.330$ and ${\text{UTS}}_{fast}=0.202\text{ln}\left(v\right)-0.023$. To estimate the UTS at speeds achieved during sonication, we extrapolate ${\text{UTS}}_{fast}$ to v = 1000 m/s, which gives a UTS of 1.5 GPa for RiAFP and a 1.4 GPa for SBAFP. To see this figure in color, go online.