NMR studies on the denatured states of proteins indicate that residual structure often resides predominantly in hydrophobic clusters. Such hydrophobic cluster formation implies burial of apolar surface and, consequently, is expected to cause a decrease in heat capacity. We report here that, in the case of ribonuclease H from the thermophile Thermus thermophilus, a sharp decrease in denatured-st...

The teleost Fundulus heteroclitus (L.) possesses two loci, Gpi-A and Gpi-B, for the glycolytic enzyme, glucose-phosphate isomerase (GPI; D-glucose-6-phosphate ketol-isomerase; E.C. 5.3.1.9). The Gpi-B locus is polymorphic in Fundulus, with two common alleles, Gpi-Bb and Gpi-Bc, distributed in a clinal manner in populations along the east coast of North America. Since this clinal distribution is...

In media containing collagen as the nitrogen source, the pathogenic yeast Candida albicans secreted a collagenolytic enzyme. Purification of the enzyme from a culture filtrate was achieved by DEAE-Sephacel chromatography at pH 6.7. The molecular weight was found to be 46,000 by 10% sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and the isoelectric point was at pH 4.2. The pH optimum...

Circular dichroism (CD) and UV absorption data showed that poly[d(G-C)] (at 0.09M NaCl, 0.01M Na+ (phosphate), 20 degrees C) underwent two conformational transitions upon lowering of the pH by the addition of HCl. The first transition was complete at about pH 3.0. The second transition was complete upon lowering the pH to 2.6 or upon raising the temperature, at pH 3.0, to about 40 degrees C. Th...

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...

1. Reported effects of different conditions on the stability of the purified chlorophyll-protein complex have been confirmed. 2. The electrophoretic behavior of the chlorophyll-protein complex prepared from two unrelated species of plants (Aspidistra elatior and Phaseolus vulgaris) has been investigated and shown to be dissimilar. In M/50 acetate buffer at 25 degrees C, the isoelectric point of...

Simplified methods are described for the measurement of human plasma renin "concentration" (PRC) and "activity" (PRA) based on the denaturation of renin substrate in which separation and concentration steps are avoided and recovery of renin is complete. In the PRA method effective inhibition of angiotensinase is achieved by warming plasma at pH 4.5 with EDTA followed by dialysis to pH 7.5. Neit...

The effect of the sugars sucrose, glucose, and trehalose on the structural and colloidal stability of lysozyme has been investigated using differential scanning calorimetry and quasi-elastic light scattering, respectively. While sugars are known to increase the temperature at which thermal denaturation of protein occurs, it is not clear if, under the same solution conditions, greater colloidal ...

In the preceding communication, the molecular properties of pepsinogen in water and water-urea solutions were evaluated (1). In this report the rates of unfolding of pepsinogen as a function of pH and temperature in urea solutions are presented. A comparison can then be made between the influence of these variables on pepsinogen denaturation and the results of a similar study reported several y...

Total enzyme activity of whole viscera, and partial characterization of acidic proteases from Monterey sardine viscera are presented. Major proteolytic activity in alkali (pH 10) and minor activity in acid (pH 3) were detected. From purified acidic proteases, six fractions with high activity were selected. One fraction (42) showed one band on SDS–PAGE and two bands on isoelectrofocusing, with p...