Different pathways in mechanical unfolding/folding cycle of a single semiflexible polymer.
Kinetics of conformational change of a semiflexible polymer under mechanical external field were investigated with Langevin dynamics simulations. It is found that a semiflexible polymer exhibits large hysteresis in mechanical folding/unfolding cycle even with a slow operation, whereas in a flexible polymer, the hysteresis almost disappears at a sufficiently slow operation. This suggests that the essential features of the structural transition of a semiflexible polymer should be interpreted at least on a two-dimensional phase space. The appearance of such large hysteresis is discussed in relation to different pathways in the loading and unloading processes. By using a minimal two-variable model, the hysteresis loop is described in terms of different pathways on the transition between two stable states.
Yoshinaga
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N
Department of Physics, Graduate School of Sciences, Kyoto University, 606-8502 Kyoto, Japan. yoshinaga@scphys.kyoto-u.ac.jp
Yoshikawa
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K
Ohta
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T