{ "dc.contributor.author": "Torrent i Mas, Joan" , "dc.contributor.author": "Marchal, Stéphane" , "dc.contributor.author": "Ribó i Panosa, Marc" , "dc.contributor.author": "Vilanova i Brugués, Maria" , "dc.contributor.author": "Georges, Cédric" , "dc.contributor.author": "Dupont, Yves" , "dc.contributor.author": "Lange, Reinhard" , "dc.date.accessioned": "2011-09-14T15:52:57Z" , "dc.date.available": "2011-09-14T15:52:57Z" , "dc.date.issued": "2008" , "dc.identifier.citation": "Torrent ,J., Marchal, S., Ribó, M., Vilanova, M., Georges, C., Dupont, Y., i Lange, R. (2008). Distinct unfolding and refolding pathways of ribonuclease a revealed by heating and cooling temperature jumps. Biophysical Journal, 94 (10), 4056-4065. Recuperat 14 setembre de 2011, a doi:10.1529/biophysj.107.123893" , "dc.identifier.issn": "0006-3495" , "dc.identifier.uri": "http://hdl.handle.net/10256/3562" , "dc.description.abstract": "Heating and cooling temperature jumps (T-jumps) were performed using a newly developed technique to trigger unfolding and refolding of wild-type ribonuclease A and a tryptophan-containing variant (Y115W). From the linear Arrhenius plots of the microscopic folding and unfolding rate constants, activation enthalpy (ΔH#), and activation entropy (ΔS#) were determined to characterize the kinetic transition states (TS) for the unfolding and refolding reactions. The single TS of the wild-type protein was split into three for the Y115W variant. Two of these transition states, TS1 and TS2, characterize a slow kinetic phase, and one, TS3, a fast phase. Heating T-jumps induced protein unfolding via TS2 and TS3; cooling T-jumps induced refolding via TS1 and TS3. The observed speed of the fast phase increased at lower temperature, due to a strongly negative ΔH# of the folding-rate constant. The results are consistent with a path-dependent protein folding/unfolding mechanism. TS1 and TS2 are likely to reflect X-Pro114 isomerization in the folded and unfolded protein, respectively, and TS3 the local conformational change of the β-hairpin comprising Trp115. A very fast protein folding/unfolding phase appears to precede both processes. The path dependence of the observed kinetics is suggestive of a rugged energy protein folding funne" , "dc.description.sponsorship": "This work was carried out in the frame of COST Chemistry D30-WG005 cooperation and supported by a grant (BFU2006-15543-CO2-02/BMC) from the Ministerio de Educacio´n y Ciencia (Spain)" , "dc.format.mimetype": "application/pdf" , "dc.language.iso": "eng" , "dc.publisher": "Biophysical Society" , "dc.relation": "MEC/PN 2006-2009/BFU2006-15543-CO2-02" , "dc.relation.isformatof": "Reproducció digital del document publicat a: http://dx.doi.org/10.1529/biophysj.107.123893" , "dc.relation.ispartof": "© Biophysical Journal, 2008, vol. 94, núm. 10, p.4056-4065" , "dc.relation.ispartofseries": "Articles publicats (D-B)" , "dc.rights": "Tots els drets reservats" , "dc.subject": "Ribonucleases" , "dc.subject": "Calor" , "dc.subject": "Fred" , "dc.subject": "Química -- Simulació per ordinador" , "dc.subject": "Chemistry -- Computer simulation" , "dc.subject": "Cold" , "dc.subject": "Heat" , "dc.title": "Distinct Unfolding and Refolding Pathways of Ribonuclease A Revealed by Heating and Cooling Temperature Jumps" , "dc.type": "info:eu-repo/semantics/article" , "dc.rights.accessRights": "info:eu-repo/semantics/openAccess" , "dc.type.version": "info:eu-repo/semantics/publishedVersion" , "dc.identifier.doi": "http://dx.doi.org/10.1529/biophysj.107.123893" , "dc.identifier.idgrec": "009776" , "dc.contributor.funder": "Ministerio de Educación y Ciencia (Espanya)" }