Effects of pH and milk constituents (milk ultrafiltrate and ~:-casein) on denaturation of fl-lactoglobulin were investigated by a dynamic method based on differential scanning calorimetry. The apparent reaction order of /Ltactoglobulin denaturation by the dynamic method was 2.0 over the pH range of 4.0 to 9.0, which is in fair agreement with results by other investigators using more classical m...

the interaction between nano-sio2 and lysozyme was investigated by the method of uv-visible  detection and fluorescence spectroscopic techniques. the thermal denaturation of lysozyme has been investigated in the presence and absence of nano-sio2 over the temperature range (293-373) k in different buffers and ph values, using temperature scanning spectroscopy. the presence of nano-sio2 caused th...

Absorbance versus temperature curves can provide information on the thermal stability of DNA or RNA quadruplexes. Quadruplex denaturation or renaturation can be followed by recording absorbance at 295 nm rather than 260 nm, the wavelength used to monitor duplex denaturation. This unit describes the use of absorbance versus temperature curves to determine melting temperatures (T(m) values) and m...

We study the static and dynamical properties of DNA in the vicinity of its melting transition, i.e., the separation of the two strands upon heating. The investigation is based on a simple mechanical model which includes the helicoidal geometry of the molecule and allows an exact numerical evaluation of its thermodynamical properties. Dynamical simulations of long-enough molecular segments allow...

Andreas Hanke Department of Physics and Astronomy, University of Texas, 80 Fort Brown, Brownsville Abstract While the Watson-Crick double-strand is the thermodynamically stable state of DNA in a wide range of temperature and salt conditions even at physiological conditions local denaturation bubbles may open up spontaneously due to thermal activation. By rising the ambient temperature, titratio...

Thermal denaturation of RNA free coat proteins of tobacco mosaic virus (TMV) was studied for wildtype TMV (vulgare) and the temperature-sensitive mutant, Ni 118. The ability to form soluble aggregates as well as the optical properties (ORD, UV-difference spectra), and the sedimen­ tation behavior were used as criteria for the native state. At pH 7.5 , 7 = 0 .0 2 denaturation is reversible for b...

The thermal denaturation of the dimeric enzyme triosephosphate isomerase (TIM) from Saccharomyces cerevisiae was studied by spectroscopic and calorimetric methods. At low protein concentration the structural transition proved to be reversible in thermal scannings conducted at a rate greater than 1.0 degrees C min(-1). Under these conditions, however, the denaturation-renaturation cycle exhibite...

Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) were used to monitor changes in the secondary structure and thermal stability of beta-lactoglobulin A and B in the presence of sodium dodecyl sulphate (SDS), N-ethylmaleimide (NEM), urea and cysteine. An increase in the thermal stabilities of both proteins was noted in the presence of 10 mM-SDS. In the pr...