Figure 6. Variability of the unfolding of the transmembrane segments in the closed state.

(a) A representative F–D curve in the closed state (the same as in Fig. 5a). Continuous black lines obtained from the fitting with WLC model. Horizontal lines indicate the corresponding values of ΔLc and ΣΔLc. (b) Histogram of ΔLc_closed(3/4) (bin 2 nm) in the closed state between the force peaks with Lc values around 159 to 189 nm. Colours correspond to different clusters of F–D curves with values of ΔLc_closed(3/4) around 26, 34 and 50 nm. (c) Superposition of representative F–D curves of the three clusters of b and the relative number of stretched a.a. (d–f) Schematic representation of the corresponding unfolding pathways. Small red dots or circles indicate the position of the force peaks, and the number is the corresponding value of Lc. The a.a. that presumably corresponds to the force peak is also indicated. (g) ΣΔLc_closed(TM) histogram (bin 1 nm) in the closed state for the force peaks as in a with values around 113, 123 and 131 nm. (h) Superposition of representative F–D curves of the three clusters of g and the relative number of stretched a.a.