Figure 6. Calculated strain of preCol domains during thread elongation.
This graph illustrates the predicted strain of the combined flanking and His-rich domains of a single preCol-NG or -D molecule during thread extension assuming a series model of preCol alignment and based on the calculated resting length of each. Horizontal dashed lines represent calculated maximal extension strains for the flanking/His-rich domains of preCol-NG and -D. The thread strain value at which the calculated molecular strain crosses the respective dashed line (indicated by a dashed circle) denotes the maximum possible thread strain following unraveling of the folded flank/His-rich domain of each particular preCol variant. Since threads are extensible to ∼100% strain, these calculations indicate that the extension of preCol domains can account half of this value. This suggests that higher order hierarchical structures must also play a role. The collagen strain calculated from the WAXD results is also included in the figure.