Cold-adapted enzymes have gained considerable attention as biocatalysts that show high catalytic activity at low temperatures. However, the use of cold-adapted enzymes at ambient temperatures has been hindered by their low thermal stabilities caused by their inherent structural flexibilities. Accordingly, protein engineering and immobilization have been employed to improve the thermal stability...

Blends of collagen dispersion (COL) with poly(vinyl alcohol) (PVA) in different weight ratios were investigated by oscillatory rheometry, Fourier transform-infrared spectroscopy and scanning electron microscopy. It was found that even with 80% of PVA, the COL/PVA blends behaved more like collagen dispersion than pure PVA solution in the dynamic thermal and frequency processing, for instance, a ...

Calorimetry has been employed to investigate the quantitative energetic aspects and mechanism underlying protein–tetraethylammonium bromide (TEAB) interactions. Differential scanning calorimetry and UV–Visible spectroscopy have been used to study the thermal unfolding of three proteins of different structure and function (bovine serum albumin, a-lactalbumin, and bovine pancreatic ribonuclease A...

Thermal denaturation profiles of an oligodeoxynucleotide that forms a hairpin structure with a cytidine-rich loop show an unexpected transition at 60 degrees C at pH 5.0 but not at pH 8.0. Analytical ultracentrifugation shows that this transition reflects dimer formation via the interaction of loops from two molecules to form a novel structure termed the h-dimer. The dependence of this structur...

Flagella were prepared and purified in a relatively intact form from bacterial lysates. Immunochemical tests showed that over 95% of the protein in the final preparation consisted of flagellar antigen. These flagella are more stable to thermal denaturation than flagella filaments obtained by shearing. Their thermal properties more closely resemble those of flagella in the native state on bacter...

Understanding the thermal denaturation process of DNA provides insight into other biological processes that involve denaturation. Examining bubbles in DNA investigates the intermediate states that exist in this important melting transition. Information can be gathered by studying the impact the location of a defect that will nucleate a bubble has on the amount of bubble states that form. A rela...

In the present study, the interaction between nano-TiO2 and lysozyme was investigated by the method of UV-Vis detection and fluorescence spectroscopic techniques. The thermal denaturation of lysozyme has been investigated in the presence and absence of nano-TiO2 over the temperature range (293-373) K in different buffer and pH, using temperature scanning spectrosc...

Maintaining protein conformational stability and integrity during formulation is critical for developing protein pharmaceuticals. Accordingly, high sensitivity differential scanning calorimetry (HSDSC) and Fourier transform (FT)-Raman spectroscopy were employed to assess conformational stabilities (thermal stability and folding reversibility) and structural integrities, respectively, for three ...

Modification with acetic anhydride of nucleosomes from chicken erythrocytes at low ionic strength (less than 0.1 M NaCl) is accompanied by the formation of residual particles and the release of free DNA. This DNA has been identified as single-stranded by thermal denaturation, digestion with nuclease S1, and elution from hydroxyapatite. In contrast, if modification takes place at 0.6 M NaCl, the...

The thermal denaturation of aspartate transcarbamoylas of Escherichia coli was investigated by differential scanning calorimetry. Isolated regulatory and catalytic subunits were heat denatured at 55 and 80 degrees C, respectively. In contrast, the intact enzyme was denatured in two steps. A small endotherm near 73 degrees C was assoicated with denaturation of the regulatory subunits and the maj...