Figure 1

SDS-mediated activation profile. Peptide-hydrolyzing activity of the 20S proteasome was carried out in a 200 μl reaction mixture containing 50 mM Tris-HCl, pH 7.6, 1 μg/ml 20S proteasome, and 10 μM peptidyl substrates (A: Suc-LLVY-MCA for chymotrypsin-like activity; B: Z-LLE-MCA for PGPH activity; C: Boc-LRR-MCA for trypsin-like activity) and increasing concentrations of SDS at 37°C for 1 h. The reactions were started and stopped as described in methods. Symbols represent the wild-type strain (○) and the rpt6-1 mutant (●). Values are means ± SD of three independent experiments.