FIGURE 6.
A small percentage of barstar molecules exhibit putative unfolding events. (A) Representative force-extension curves of (GB1)4-barstar-(GB1)4 show putative unfolding events of barstar. In these force-extension curves, unfolding events of ΔL of ∼30 nm were observed (colored in gray), which coincide with the ΔL expected from complete unfolding of barstar. Thin lines show the WLC fits of ΔL of ∼18 nm and∼30 nm, respectively. (B) Histogram of contour length increment of putative barstar unfolding events. It is important to note that such putative unfolding events of barstar are a small percentage of the events observed in our single-molecule AFM experiments.