FIGURE 4.
Most of oxidized PTPs are associated with large molecular assemblies. BMMCs were either nonactivated (Control) or activated with 5 mm H2O2, 0.2 mm Pv, or TNP/BSA (Ag; 0.5 μg/ml). After 5 min, the cells were permeabilized with 0.1% saponin, and the material released from the cells was removed (Sap.). The cell ghosts were then extracted for 15 min on ice in lysis buffer supplemented with 1% Triton X-100, and the postnuclear supernatant (Triton) was harvested. Both supernatants, saponin and Triton, were size-fractionated by SDS-PAGE and analyzed by immunoblotting (IB) with oxPTP mAb and after stripping with anti-SHP-1 antibody to check for the amount of this phosphatase (bottom, arrow). Representative data from three experiments are shown. Numbers on the right indicate positions of molecular mass markers (kDa).