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Role of conformational entropy in force-induced bio-polymer unfolding

Sanjay Kumar·Iwan Jensen·Jesper L. Jacobsen·Anthony J. Guttmann
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Abstract

A statistical mechanical description of flexible and semi-flexible polymer chains in a poor solvent is developed in the constant force and constant distance ensembles. We predict the existence of many intermediate states at low temperatures stabilized by the force. A unified response to pulling and compressing forces has been obtained in the constant distance ensemble. We show the signature of a cross-over length which increases linearly with the chain length. Below this cross-over length, the critical force of unfolding decreases with temperature, while above, it increases with temperature. For stiff chains, we report for the first time "saw-tooth" like behavior in the force-extension curves which has been seen earlier in the case of protein unfolding.

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Sanjay Kumar, Iwan Jensen, Jesper L. Jacobsen, Anthony J. Guttmann. 2007-02-19. Role of conformational entropy in force-induced bio-polymer unfolding. https://arxiv.org/abs/cond-mat/0702436

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