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arXiv · 1507.01376

Understanding the dependence on the pulling speed of the unfolding pathway of proteins

C. A. Plata·F. Cecconi·M. Chinappi·A. Prados
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Abstract

The dependence of the unfolding pathway of proteins on the pulling speed is investigated. This is done by introducing a simple one-dimensional chain comprising $N$ units, with different characteristic bistable free energies. These units represent either each of the modules in a modular protein or each of the intermediate "unfoldons" in a protein domain, which can be either folded or unfolded. The system is pulled by applying a force to the last unit of the chain, and the units unravel following a preferred sequence. We show that the unfolding sequence strongly depends on the pulling velocity $v_{p}$. In the simplest situation, there appears a critical pulling speed $v_{c}$: for pulling speeds $v_{p} v_{c}$ it is the pulled unit that unfolds first. By means of a perturbative expansion, we find quite an accurate expression for this critical velocity.

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BibTeXRIS

C. A. Plata, F. Cecconi, M. Chinappi, A. Prados. 2015-07-06. Understanding the dependence on the pulling speed of the unfolding pathway of proteins. https://doi.org/10.1088/1742-5468/2015/08/p08003

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