The preparation and properties of a highly active catalase from horse liver

Abstract

The prep. was a protein with an Fe-content of 0.085-0.005% and a Cu-content of 0.02-0.03%, and had an activity of 55,000-60,000. In the Theorell cataph-oresis apparatus the catalase activity migrated proportionally with the N, Fe and Cu. The sedimentation constant was found to be 11.3 X 10-13 and the molecular wt. calculated to be 225,000. By adding picric acid and acetic acid to a slightly alkaline soln. of catalase a precipitate appeared at pH 5.2. By further addition of acetic acid another fraction precipitated at pH 4.6. The fraction which was first precipitated had an Fe-content of about 0.1% and almost no Cu, while the other fraction had a Cu-content of about 0.16% and very little Fe. Each fraction had a considerably lower activity than the original prep. The activity was not restored by a simple mixing of the 2 fractions.