Studies on acid hydrolysis of proteins.

At the present time all known methods for the hydrolysis of proteins are subject to serious limitations. Enzymatic hydrolysis is slow and incomplete, alkalis racemize the optically active amino acids and destroy cystine and arginine, and acid hydrolysis is accompanied by humin formation and tryptophane destruction. The destruction of tryptophane during acid hydrolysis is not, in all cases, due to the direct action of the acid since pure tryptophane is relatively stable in hot dilute sulphuric and hydrochloric acids. The destruction must, therefore, be due to some other constituent or constituents of the protein. Consequently, there is some reasonable prospect that tryptophane destruction can be avoided if the harmful effects of these other agents can be eliminated. [...