Viscosity analysis of the temperature dependence of the solution conformation of ovalbumin Original Research Article

The viscosity of ovalbumin aqueous solutions was studied as a function of temperature and of protein concentration. Viscosity–temperature dependence was discussed on the basis of the modified Arrhenius formula at temperatures ranging from 5 to 55°C. The activation energy of viscous flow for hydrated and unhydrated ovalbumin was calculated. Viscosity–concentration dependence, in turn, was discussed on the basis of Mooney equation. It has been shown that the shape parameter S decreases with increasing temperature, and self-crowding factor K does not depend on temperature. At low concentration limit the numerical values of the intrinsic viscosity and of Huggins coefficient were calculated. A master curve relating the specific viscosity ηsp to the reduced concentration c[η], over the whole range of temperature, was obtained and the three ranges of concentrations: diluted, semi-diluted and concentrated, are discussed. It has been proved that the Mark–Houvink–Kuhn–Sakurada (MHKS) exponent for ovalbumin does not depend on temperature.