[Properties and action specificity of carboxycathepsin (peptidyl dipepsidase) from bovine kidneys]

Carboxycathepsin from bovine kidney split the dipeptide fragments from the C-terminal part of peptides of different structure. Peptides containing the proline residue at the second position from the C-terminal amino acid residue and also peptides with substituted terminal alpha-carboxyl group were not hydrolyzed by carboxycathepsin. The enzyme was activated by Cl, Zn2+, Co2+ and Mn2+. The substances which formed the chelate complexes with ions of two-valent metals and also heavy metal ions, inhibited the enzymatic activity. Diisopropyl fluorophosphate did not inhibit carboxycathepsin. The homogeneous preparation of carboxycathepsin converted angiotensin 1 into angiotensin 11 and hydrolyzed bradikinine, splitting off C-terminal dipeptides consequentially.