Bonilla, Luis L.Carpio Rodríguez, Ana MaríaPrados, Antonio2023-06-192023-06-192014Bonilla, L. L., Carpio Rodríguez, A. M., Prados, A. «Protein unfolding and refolding as transitions through virtual states». EPL (Europhysics Letters), vol. 108, n.o 2, octubre de 2014, p. 28002. DOI.org (Crossref), https://doi.org/10.1209/0295-5075/108/28002.0295-507510.1209/0295-5075/108/28002https://hdl.handle.net/20.500.14352/33867Single-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.engjournal articlehttps://doi.org/10.1209/0295-5075/108/28002http://iopscience.iop.org/0295-5075/108/2/28002open access51PACS 87.15.Cc –Folding: thermodynamicsStatistical mechanicsModels and pathwaysPACS 05.40.-a – Fluctuation phenomenaRandom processesNoise and Brownian motionPACS 87.14.et – Generic models (latticeHPMatemáticas (Matemáticas)12 Matemáticas