Comparative study of thermal stability of healthy and focal segmental glomerulosclerosis plasma albumin

The thermodynamic parameters calculated from measurements obtained by differential scanning calorimetry from healthy and focal segmental glomerulosclerosis albumin are reported. The same values were determined by fluorescence spectra and by the second derivative absorption spectra and they resulted in agreement with values obtained from the calorimetry technique. Nevertheless the unfolding mechanism seems to be completely altered when pathological albumin is compared with healthy albumin. The C _p values measured by calorimetry show an increase with mild slope with healthy protein; on the contrary the slope intensely increase with pathological protein. Furthermore the λ_max of this molecule is lower and drastically decrease with the increase of temperature when compared with healthy one. Therefore the modification of cys 34 on pathological albumin is supposed to cause an alteration of the structure, the swelling and the unfolding mechanism.