The Enzyme System Transferring the Amino-Group of Aspartic Acid

Abstract

I HAVE, in recent communications^1,2, described a method for the preparation of a purified enzyme from muscle tissue, catalysing the reversible transfer of amino nitrogen from glutamic acid to monocarboxylic α-ketoacids³. The enzyme preparation is inactive with regard to the Umaminierung, or ‘trans-amination’ of aspartic acid, whereas this process is readily effected by the original muscle pulp⁴. I have since been successful in obtaining from muscle tissue, by means of a modified purification scheme to be described in detail elsewhere, enzyme preparations catalysing the transamination of aspartic acid at a considerable rate in the presence of a thermostable activator, or coenzyme, contained in tissue extracts.