A statistical model of homopolymer DNA, coupling internal base-pair states (unbroken or broken) and external thermal chain fluctuations, is exactly solved using transfer kernel techniques. The dependence on temperature and DNA length of the fraction of denaturation bubbles and their correlation length is deduced. The thermal denaturation transition emerges naturally when the chain fluctuations ...

To clarify mechanisms of folding and unfolding of proteins, many studies of thermal denaturation of proteins have been carried out at low protein concentrations because in many cases thermal denaturation accompanies a great tendency of aggregation. As small-angle x-ray scattering (SAXS) measurements are liable to use low-concentration solutions of proteins to avoid aggregation, SAXS has been re...

The base composition in moles percent guanine plus cytosine (%GC) of both nuclear and mitochondrial deoxyribonucleic acid (DNA) isolated from the yeastlike and mycelial phases of the dimorphic fungal pathogens Histoplasma capsulatum and Blastomyces dermatitidis was determined by techniques of thermal denaturation and CsCl buoyant density gradient equilibrium centrifugation. The mean observed va...

Thermal denaturation of protonated polynucleotides is accompanied by a change in protonation [l-5] . The thermal transition at a given pH can thus be directly related to the pk’ of the proton-induced structural transition at a given temperature. For poly (A’).poly (A+) a strict relationship has been shown to hold over a large range of conditions [4-61. In fig. 1 the results in the literature an...

The effect of temperature and calcium ions on the denaturation of a recombinant alpha-amylase from Bacillus halmapalus alpha-amylase (BHA) has been studied using calorimetry. It was found that thermal inactivation of BHA is irreversible and that calcium ions have a significant effect on stability. Thus an apparent denaturation temperature ( T (d)) of 83 degrees C in the presence of excess calci...

Protein denaturation is considered to be the main reason for both water loss and textural changes in fish during thermal processing. Denaturation of proteins in muscle of farmed Atlantic cod was studied by differential scanning calorimetry. The denaturation of the proteins was compared to cook loss and loss in water holding capacity and it was shown that the protein denaturation occurs in a low...

The effect of Mg2+ on the thermal inactivation and unfolding of rabbit muscle creatine kinase has been studied for various temperatures and Mg2+ concentrations. Increasing the Mg2+ concentration in the denatured system significantly enhanced the inactivation and unfolding of creatine kinase during thermal denaturation. The analysis of the kinetic course of substrate reaction during thermal inac...

Differential scanning calorimetry (DSC) was applied to elucidate the thermal behavior of fowl feather keratins (barbs, rachis, and calamus) with different morphological features. The DSC curves exhibited a clear and relatively large endothermic peak at about 110-160 degrees C in the wet condition. A considerable decrease in transition temperature with urea and its helical structure content esti...

in this study at first , an azo dye, 2,7- naphthalenediol, 2-[(4-bromophenyl)azo (bpand) as a ligand has been synthesized by addition of p-bromoaniline to the modified montomorillonite k10 clay. this ligand was characterized using 1h-nmr, uv-vis and ir spectroscopies. subsequently, its interaction with calf thymus deoxyribonucleicacid ,ct-dna was investigated in 5 mm phosphate buffer solution, ...