title: Cold denaturation of ubiquitin.
abstract: Temperature induced unfolding of bovine ubiquitin in solutions with different concentrations of guanidinium hydrochloride (GdmCl) has been measured using differential scanning calorimetry. It has been shown that at high concentrations of GdmCl the ubiquitin molecule can undergo both heat and cold induced denaturation. Analysis of the enthalpy of unfolding of ubiquitin in the presence of GdmCl shows a good agreement with the thermodynamic denaturant binding model. The unfolding Gibbs energy is found to change linearly with guanidine concentration up to zero denaturant concentration.
authors.affiliation: Facultad de Ciencias, Departamento de Quimica Fisica, Granada, Spain.
authors.forename: B
authors.initials: B
authors.lastname: Ibarra-Molero
authors.forename: G I
authors.initials: GI
authors.lastname: Makhatadze
authors.forename: J M
authors.initials: JM
authors.lastname: Sanchez-Ruiz
mesh_terms: D002152:Calorimetry, Differential Scanning; D003080:Cold Temperature; D019791:Guanidine; D006863:Hydrogen-Ion Concentration; D011489:Protein Denaturation; D012996:Solutions; D013816:Thermodynamics; D014452:Ubiquitins / Q000737:chemistry*