Fig. 1
Trigger factor and the folding dynamics of protein L. a Schematics of the magnetic tweezers experiment, showing the octamer of protein L tethered between a glass coverslip and the paramagnetic bead. The force is applied by changing the separation of the permanent magnets and the bead. b Dynamics of protein L octamer at three different forces with (red) and without (black) TF. First, the protein is fully unfolded by a fingerprint pulse, where the eight unfolding events are identified as eight length steps. Second, a refolding pulse is set at a lower force (4.3, 7.4 and 11.9 pN, from bottom to top). At 4.3 pN (faint color, lowest length) all domains are able to fold by themselves, leading to a maximum probability of folding. Therefore, TF does not do any significant effect. At 11.9 pN (faint color, highest length), the protein is not able to refold (0 probability of folding) and TF does not either affect the probability of folding. In the intermediate force range (7.4 pN, solid colors) TF greatly increases the probability of folding, reflected in a higher number of folded domains
