OBSERVATION OF UNFREEZABLE WATER IN AQUEOUS-SOLUTION OF GLOBULE PROTEIN BY MICROWAVE DIELECTRIC MEASUREMENT

A freezing process analyzed by the dielectric method on aqueous soluti on of albumin has revealed water structure around protein molecule. A relaxation peak due to bound water attached on the protein surface aro und 100 MHz at room temperature was found. It could be seen commonly i n globule proteins. Another peak due to a different kind of unfreezabl e water was found around 1 GHz at -6 degrees C. The amount of this wat er is estimated as 0.36 g water/g protein and in good agreement with t hat obtained by differential scanning calorimetry and nmr measurements . The water molecules form a shell layer around the protein molecule. (C) 1995 John Wiley & Sons, Inc.