Temperature dependent mechanical unfolding and refolding of a protein studied by thermo-regulated optical tweezers

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dc.contributor.authorRivera, Maira
dc.contributor.authorMjaavatten, Are
dc.contributor.authorSmith, Steven B.
dc.contributor.authorBaez, Mauricio
dc.contributor.authorWilson, Christian A. M.
dc.date.accessioned2025-01-20T20:10:52Z
dc.date.available2025-01-20T20:10:52Z
dc.date.issued2023
dc.description.abstractTemperature is a useful system variable to gather kinetic and thermodynamic information from proteins. Usually, free energy and the associated entropic and enthalpic contributions are obtained by quantifying the conformational equilibrium based on melting experiments performed in bulk conditions. Such experiments are suitable only for those small single-domain proteins whose side reactions of irreversible aggregation are unlikely to occur. Here, we avoid aggregation by pulling single-protein molecules in a thermo-regulated optical tweezers. Thus, we are able to explore the temperature dependence of the thermodynamic and kinetic pa-rameters of MJ0366 from Methanocaldococcus jannaschii at the single-molecule level. By performing force-ramp experiments be-tween 2 degrees C and 40 degrees C, we found that MJ0366 has a nonlinear dependence of free energy with temperature and a specific heat change of 2.3 5 1.2 kcal/mol*K. These thermodynamic parameters are compatible with a two-state unfolding/refolding mechanism for MJ0366. However, the kinetics measured as a function of the temperature show a complex behavior, suggesting a three-state folding mechanism comprising a high-energy intermediate state. The combination of two perturbations, temperature and force, reveals a high-energy species in the folding mechanism of MJ0366 not detected in force-ramp experiments at constant temperature.
dc.fuente.origenWOS
dc.identifier.doi10.1016/j.bpj.2022.12.034
dc.identifier.eissn1542-0086
dc.identifier.issn0006-3495
dc.identifier.urihttps://doi.org/10.1016/j.bpj.2022.12.034
dc.identifier.urihttps://repositorio.uc.cl/handle/11534/92102
dc.identifier.wosidWOS:001003136500001
dc.issue.numero3
dc.language.isoen
dc.pagina.final521
dc.pagina.inicio513
dc.revistaBiophysical journal
dc.rightsacceso restringido
dc.titleTemperature dependent mechanical unfolding and refolding of a protein studied by thermo-regulated optical tweezers
dc.typeartículo
dc.volumen122
sipa.indexWOS
sipa.trazabilidadWOS;2025-01-12
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