[The role of vitrification in maintaining protein native structure during dehydration].

Concentration dependencies of maximum temperature (Td), thermal effect of denaturation (delta Qd) and also of glass transition temperature (Tg) were obtained in heat capacity investigation of five globular proteins with low water content. Special features of the observed Td and delta Qd dependencies, both general for polymers and specific for proteins, are discussed. The assumption is put forward that anomalously strong dependence of protein Tg on humidity, bringing together glass and denaturation transitions, results in the fact that denaturation process can be observed in completely dehydrated proteins.

Thermodynamic compatibility of proteins in aqueous media. Part 3. Studies on the role of intermolecular interactions in the thermodynamics of compatibility of proteins according to the data of dilution enthalpies.

The flow microcalorimetric method was used to determine the enthalpies of diluting solutions of ovalbumin, bovine serum albumin, casein, soybean globulin fraction, thermotropic aggregates of ovalbumin, mixtures of ovalbumin-bovine serum albumin, casein-soybean globulin fraction, and ovalbumin-thermotropic aggregates of ovalbumin in water. The calorimetric data obtained were compared with the data on phase equilibrium in the systems Water-Ovalbumin-Bovine serum albumin, Water-Casein-Soybean globulin fraction, Water-Ovalbumin-Thermotropic aggregates of ovalbumin. Intermolecular interactions have been shown to play a significant role in the thermodynamics of protein compatibility.

Thermodynamic compatibility of proteins in aqueous media. Part 2. The effect of some physicochemical factors on thermodynamic compatibility of casein and soybean globulin fraction.

A study has been made on the effect of temperature, sodium chloride, pH and cysteine on the thermodynamic compatibility of casein and soybean globulin fraction in aqueous medium. The section of miscibility gap characterizing the influence of the indicated factors on the compatibility of proteins has been determined. Assessment has been made of the influence of pH and cysteine on a) the effective molecular weights of casein and soybean globulin fraction and b) the difference in the intensity of interaction between each protein and a solvent.