title: IATC, DSC, and PPC Analysis of Reversible and Multistate Structural Transition of Cytochrome c.
abstract: Development of precise calorimeters has enabled us to monitor the structural transition of biomolecules by calorimetry to characterize the thermodynamic property changes accompanying three-dimensional structure change. We developed isothermal acid-titration calorimetry to evaluate the pH dependence of protein enthalpy, and demonstrated the thermodynamic transition between the native and molten globule (MG) states of cytochrome c with very small enthalpy change (~20 kJ/mol) by this method. The double deconvolution method with precise differential scanning calorimetry has revealed the MG state as an equilibrium intermediate state of the reversible thermal transition of the protein, and pressure perturbation calorimetry has succeeded in determining its volumetric properties. These examples strongly indicate the importance of a precise calorimetry and analysis model in the field of protein research.
authors.affiliation: Department of Bioengineering, Nagaoka University of Technology, Nagaoka, Japan. Electronic address: kidokoro@nagaokaut.ac.jp.
authors.forename: Shun-ichi
authors.initials: S
authors.lastname: Kidokoro
authors.affiliation: Department of Bioengineering, Nagaoka University of Technology, Nagaoka, Japan.
authors.forename: Shigeyoshi
authors.initials: S
authors.lastname: Nakamura
mesh_terms: D002151:Calorimetry / Q000379:methods*; D045304:Cytochromes c / Q000378:metabolism*; D017510:Protein Folding; D013816:Thermodynamics
chemical_list: D045304:Cytochromes c
keywords: Enthalpy; Entropy; Folding/unfolding; Gibbs free energy; Heat capacity; Intermediate state; Molten globule; Partial specific volume; Proton binding number; Stability