The Alkaline Hydrolysis of Egg Albumin

Following the discovery of Kossel and Weiss (1) that many of the constituent amino acids are racemized when proteins are hydrolyzed by alkali, the use of alkaline hydrolysis in the analysis of proteins has been limited to the determination of amino acids which are unstable in strong acid. There is little information available as to the extent and completeness of hydrolysis as a function of [OH-] and temperature (2, 3). Vickery (4) showed that the initial reaction rate in the case of wheat gliadin was greater than that due to a comparable concentration of acid, and that it was greater with Ba(OH)2 than with an equivalent concentration of NaOH. His observations did not extend to the late stages of hydrolysis. Now alkaline hydrolysates possess some apparent advantages to the analyst. The solutions are clear and there is no precipitation of humin. When Ba(OH)t is employed, it may be readily removed. Moreover, the racemization which occurs is not necessarily a disadvantage. We have, therefore, undertaken a detailed study of the course and completeness of the alkaline hydrolysis of egg albumin under a variety of conditions.