We study cold denaturation of proteins at high pressures. Using multicanonical Monte Carlo simulations of a model protein in a water bath, we investigate the effect of water density fluctuations on protein stability. We find that above the pressure where water freezes to the dense ice phase (≈ 2 kbar), the mechanism for cold denaturation with decreasing temperature is the loss of local low-dens...

the thermal denaturation of α-amylase from bacillus amyloliquefaciens has been investigated in the presence and absence of sodium dodecyl sulphate (sds) over the temperature range (293-373) k in 20 mm sodium phosphate buffer, ph 6.9, using temperature scanning spectroscopy. the presence of sds caused the destabilization of α-amylase resulting in a decrease in the temperature of unfolding with a...

the thermal denaturation of adenosine deaminase (ada) has been investigated in the presence of sodium n-dodecyl sulphate (sds) over the temperature range of (293-363k) in 2.5 mm phosphate buffer, ph 6.4 by temperature scanning spectroscopy. the interaction of sds caused the folding of adenosine deaminanse resulting in a decrease of th (temperature of minimum solubility), ts (temperature of maxi...

Differential scanning calorimetric (DSC) measurements were performed on the thermal denaturation of lysozyme and lysozyme complexed with N-acetyl-D-glucosamine (GlcNAc) at pH 5.00 (acetate buffer), 4.25 and 2.25 (Gly-HCl buffer). DSC data have been analyzed to obtain denaturation temperature T(d), enthalpy of denaturation DeltaH(D), heat capacity of denaturation DeltaC(pd) and cooperativity ind...

We study cold denaturation of proteins at high pressures. Using multicanonical Monte Carlo simulations of a model protein in a water bath, we investigate the effect of water density fluctuations on protein stability. We find that above the pressure where water freezes to the dense ice phase (approximately 2 kbars) the mechanism for cold denaturation with decreasing temperature is the loss of lo...

Thermal denaturation of Escherichia coli maltodextrin glucosidase was studied by differential scanning calorimetry, circular dichroism (230 nm), and UV-absorption measurements (340 nm), which were respectively used to monitor heat absorption, conformational unfolding, and the production of solution turbidity. The denaturation was irreversible, and the thermal transition recorded at scan rates o...

BSA solution and the buffer used as a solvent, A is the area of the V = f(T) plot obtained for a given step of the considered thermal denaturation process and a is the part of this surface corresponding to a given temperature T. In this study some conformational changes induced by thermal denaturation of BSA macromolecule were evidenced, the temperatures of transition as well as the # G values ...

Thermal processing often results in disruption of the native conformation of whey proteins, thus affecting functional properties. The aim of this work was to evaluate the effects of moderate electric fields on denaturation kinetics and thermodynamic properties of whey protein dispersions at temperatures ranging from 75 to 90 °C. Application of electric fields led to a lower denaturation of whey...

To increase our understanding of the physical nature of the Na+ and K+ forms of the Na+ + K+-dependent ATPase, thermal-denaturation studies were conducted in different types of ionic media. Thermal-denaturation measurements were performed by measuring the regeneration of ATPase activity after slow pulse exposure to elevated temperatures. Two types of experiments were performed. First, the depen...

Solutions of fibrinogen show two endothermal (denaturing) transitions, at 61 degrees and at 100 degrees , when heated in a differential scanning calorimeter. Similar transitions are observed for a mixture of the fragments D and E obtained by limited proteolysis of fibrinogen. Isolated fragment E shows only a single transition, at 97 degrees . The independent thermal denaturation of these portio...