ATP-dependence of proteolysis in the pulp of rabbit molar teeth

The ATP-dependent proteolysis of rabbit dental pulp shares a high portion of the total proteolytic capacity in incisor and molar teeth (76 and 69%). It has been found in the fractions of homogenates containing mitochondria, cytosol and microsomes, respectively. The dependence of proteolytic activity on ATP is characterized by an apparent Michaelis constant at cellular levels of ATP (Km = 2.9 mM). The kinetics of inhibition by hemin (Ki = 115.3 microM, n = 2.8) and vanadate (Ki = 1.3 mM, n = 0.93) reveal different modes of actions of both inhibitors. The kinetic features of the ATP-dependent proteolysis in dental pulp differs from those in reticulocytes of the same animal species.