Fig. 3.
Fractionation of protease activity.
(A) Lysates of 35S-methionine–labeled blood cells were prepared (“Materials and methods”). Equal amounts were incubated alone or mixed with nonlabeled lysates of bone marrow cells and subfractions of 80 μg each. The mixtures were immunoprecipitated for 3 hours at 4°C with standard protease inhibitors before gel separation. (B) Bone marrow crude mitochondria (mit.) were further subfractionated (80 μg each) into a membrane and matrix fraction and were analyzed the same way. (C) Nonlabeled 80-μg lysates each of bone marrow, spleen, and liver tissue were mixed with the labeled blood lysate and analyzed the same way.