Statistical thermodynamic treatment of oligomeric proteins

INES BURGOS; SERGIO A. DASSIE; GERARDO D. FIDELIO

Rosario

Congreso; XXXV Reunión Anual Sociedad Argentina de Biofísica; 2006

Sociedad Argentina de Biofísica

Proteins can be treated as statistical thermodynamic systems embedded canonically in the buffer solution [1]. Differential scanning calorimetry is a fundamental tool to study the energetics of folding-unfolding of proteins in solution [2]. Statistical mechanics allow a straightforward calculation and prediction of the enthalpy and heat capacity curves from the partition function. We have developed the formalism for the denaturation of an oligomeric protein which can be in equilibrium with its monomeric form:nnNnD The statistical thermodynamic treatment is based on the canonical ensemble because in the calorimetric cell the number of proteins remains constant. Our results are compared with the previous model for oligomeric proteins developed by Rösgen and Hinz that considered the following equilibrium [3]:NnnD [1] J. Rösgen and H.J. Hinz, Biophys. Chem., 2002, 96, 109–116. [2] P.L. Privalov, Adv.Protein.Chem., 1979, 33, 167-241. [3] J. Rösgen and H.J. Hinz, Phys.Chem.Chem.Phys., 1999, 1, 2327 - 2337.