[Partial purification of a protein inhibitor of cathepsin D from rat uterus]

A protein termostable inhibitor of Cathepsine D was found in the uterus of 22 day pregnant rats. Partial purification was achieved by healing at 100 degrees C, 10 mM phosphate buffer pH 7.4 during 30 min. The supernatant of 27,000 X g was TCA precipitated and ethanol fraccionated. Cathepsine D inhibitor was found in the 45-80% ethanol fraction. Inhibitor activity was assayed on partially purified Cathepsine D from the uterus of 4 day post-partum rats. The activity was linear with the amount of inhibitor added. No Cathepsine D inhibitor was found in the uterus of 4 day post-partum rats.