Fig. 5.
Stage-wise unfolding and refolding a single gp41 SNARE complex (36). (A) Force-extension curves (FECs) obtained by pulling (black) and relaxing (cyan) the gp41 complex. The continuous regions of the FECs are fit with a worm-like chain model (red lines), revealing different gp41 folding states (6HB, 5HB, and the fully unfolded state). (B) Time-dependent extension, force, and trap separation corresponding to the force and extension shown in A. A close-up view of the region marked by the dashed box is shown as an inset.