Protein unfolding and refolding as transitions through virtual states

L. L. Bonilla; A. Carpio; A. Prados

doi:10.1209/0295-5075/108/28002

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arXiv · 1409.7900

Protein unfolding and refolding as transitions through virtual states

L. L. Bonilla·A. Carpio·A. Prados

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Abstract

Single-molecule atomic force spectroscopy probes elastic properties of titin, ubiquitin and other relevant proteins. We explain bioprotein folding dynamics under both length- and force-clamp by modeling polyprotein modules as particles in a bistable potential, weakly connected by harmonic spring linkers. Multistability of equilibrium extensions provides the characteristic sawtooth force-extension curve. We show that abrupt or stepwise unfolding and refolding under force-clamp conditions involve transitions through virtual states (which are quasi-stationary domain configurations) modified by thermal noise. These predictions agree with experimental observations.

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L. L. Bonilla, A. Carpio, A. Prados. 2014-09-28. Protein unfolding and refolding as transitions through virtual states. https://doi.org/10.1209/0295-5075%2F108%2F28002

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