Thermodynamic and structural analysis of homodimeric proteins: model of beta-lactoglobulin

INÉS BURGOS; SERGIO A. DASSIE; MARCOS A. VILLARREAL; GERARDO D. FIDELIO

ELSEVIER SCIENCE BV

Año: 2012 vol. 1824 p. 383 - 383

he energetics of protein homo-oligomerization was analyzed in detail with the application of a general thermodynamic model. We have studied the thermodynamic aspects of protein-protein interaction employing -lactoglobulin A from bovine milk at pH=6.7 where the protein is mainly in its dimeric form. We performed differential calorimetric scans at different total protein concentration and the resulting thermograms were analyzed with the thermodynamic model for oligomeric proteins previously developed. The thermodynamic model employed, allowed the prediction of the sign of the enthalpy of dimerization, the analysis of complex calorimetric profiles without transitions baselines subtraction and the obtainment of the thermodynamic parameters from the unfolding and the association processes. The dissociation and unfolding reactions were also monitored by Fourier-transform infrared spectroscopy and the results indicated that the dimer of beta-lactoglobulin (N2) reversibly dissociates