FIG. 7.

Time courses of ODC inactivation, degradation, and binding. ODC was incubated for the indicated times at 37°C in an inactivation/degradation assay mixture containing partially purified 26S proteasome that had been treated (B) or not treated (A) with clasto-lactacystin β-lactone (200 μM). ODC inactivation, degradation, and binding were determined as described in Materials and Methods. The inset (B) shows SDS-PAGE of ODC coimmunoprecipitated with anti-20S proteasome antibody after the inactivation reaction at the indicated times. The relative amounts of coimmunoprecipitated ODC (ODC binding) were quantitated with an image analyzer.