Purification and some properties of arginase from human lung.

Arginase from human lung has been isolated and purified about 100-fold. During the purification procedure the enzyme was stabilized by Mn2+. The molecular weight determined by Sephadex G-150 gel filtration was found to be 120 000. The enzyme is highly specific towards L-arginine. Incubation of the enzyme with EDTA for 60 min at pH 7.5 and 37 degrees C results in dissociation into inactive subunits of mol. wt. 30 000. On addition of Mn2+ ion to the inactivated enzyme, the subunits reassociate into the native form of the enzyme of mol. wt. 120 000, and the activity is restored.