Purification and properties of tyrosine-activating enzyme of hog pancreas.

Activation reactions of this type are catalyzed by enzymes from various sources (2-6) and specific activating enzymes may be required for each amino acid (2). The first highly purified, activating enzyme was a tryptophan-activating enzyme from beef pancreas, studied by Davie et al. (7). The isolation and properties of a tyrosine-activating enzyme from hog pancreas (8) are described in this report.