Authors:K. Michalik, Zofia Drzazga, Anna Michnik, and M. Kaszuba
scanning calorimetry study of the thermal behavior of nevirapine and azidothymidine
in water solution was carried out. For nevirapine scan rate dependent and
irreversible endothermic peak were found. Thermal degradation of nevirapine
as well as NVP – AZT mixture is relatively well described by the model
involving only one irreversible step determined by a first-order rate constant.
The estimated kinetic constants and activation energies indicate that the
degradation process proceeds slower for nevirapine in presence of AZT ligands
than without them.
Authors:Anna Michnik, K. Michalik, A. Kluczewska, and Zofia Drzazga
The thermal denaturation process of bovine and human
both fatty acid containing and fatty acid free albumins in aqueous solution
was studied by use of differential scanning calorimetry. Human serum albumins
were found to be more stable than their bovine counterparts. Fatty acid free
albumins were characterized as generally less stable, more susceptible to
aggregation, their unfolding endothermic transition was less cooperative and
with the smaller degree of reversibility. Deconvolution analysis with using
a non-two-state model with two component transitions showed essential differences
in the thermodynamic parameters between all studied albumins, particularly
regarding the high-temperature component transition.
Authors:A. Michnik, Z. Drzazga, K. Michalik, A. Barczyk, I. Santura, E. Sozańska, and W. Pierzchała
Differential scanning calorimetry (DSC) has been applied for studies of blood serum from patients sick with chronic obstructive
pulmonary disease (COPD). The denaturation of serum proceeds as endothermic process over the temperature range 45–85 °C. Distinct
changes in the shape of DSC curves have been observed for serum from patients with severe stage of COPD (treated with inhaled
corticosteroids) relative to serum from healthy individuals. The first moment of the thermal transition with respect to the
temperature axis shifts from the normal value of 63.9 ± 0.3 to 65.3 ± 0.7 °C and to 67.6 ± 1.6 °C for early and advanced stages
of disease, respectively. The results of our studies suggest age dependence of blood serum denaturation transition.