Abstract
The degree of denaturation produced in ovalbumin by urea solutions under various conditions has been followed by physical means. During denaturation optical rotation and viscosity show parallel changes and indicate that there is a critical urea concentration. This urea concentration is thought to be associated with the rupture of a linkage important for maintaining the configuration of the native protein. Changes in extinction coefficient at 295 mu and, after iodination, at 310 mu also exhibit a similar dependence upon urea concentration.