ATP activation of parathyroid hormone cleavage catalyzed by cathepsin D from bovine kidney.

The acid protease which is activated by ATP and which catalyzes production of fragments of parathyroid hormone similar to those produced in vivo was shown to be cathepsin D. Purified cathepsin D from bovine kidney and spleen is activated by ATP and other nucleoside triphosphates, and to a much lesser extent by nucleoside diphosphates and pyrophosphate. These findings suggest that cathepsin D may be involved in parathyroid hormone metabolism in vivo and that this lysosomal enzyme may be regulated by the energy status of the cell.