Fig. 5. Aconitase and fumarase and their cytosolic derivates are stable. Yeast strains harboring plasmids encoding the indicated proteins were induced in galactose medium and pulse-labeled with [35S]methionine-cysteine for 15 minutes, followed by a chase (addition of unlabeled methionine-cysteine and cycloheximide) for the times indicated. Total cell extracts were prepared, immunoprecipitated with aconitase or fumarase antiserum and analyzed by SDS-PAGE and autoradiography.