DENSITY, THERMAL EXPANSIVITY, VISCOSITY AND REFRACTIVE-INDEX OF LYSOZYME SOLUTIONS AT CRYSTAL-GROWTH CONCENTRATIONS

Lysozyme has been widely used as a model system for nucleation and crystal growth studies of globular proteins. Yet, few of the properties of lysozyme solutions, which are needed for interpreting the results of such studies, are known. We have investigated the dependence of the density, thermal expansivity, viscosity and refractive index of lysozyme solutions on protein concentration and temperature at various pH values and sodium chloride concentrations. Extensive data are presented in the form of tables and equations. In particular, we found that the solution volumes varied as T3/2. This behavior, which appears to be characteristic for a large class of liquids, suggests that thermal expansion is dominantly due to translational motion.