By method of differential scanning calorimetry the absolute values of heat capacity for the systemwater–biopolymer (globular
and fibrillar proteins and DNA) were measured in a wide range of temperatures (from -30 up to 130°C) and concentrations of
proteins both in native and denatured states. Thermal properties of humid denatured biopolymers demonstrate a characteristic
anomaly in the form of the heat capacity jump at temperature depending on the bound water content. It has been shown that
in the systems studied a glass transition, where water serves as a native plasticizer, is observed. It has been established
that the S-shaped character of all heat capacity curves obtained on dehydration for native and denatured biopolymers is due
to the gradual transition to the glassy state of both native and denatured samples. It was found that thermally denatured
humid small globular proteins at subsequent dissolving in water at room temperature are able to restore their native structure.