AMWAP does not inhibit peptidase activities of the 20S proteasome. The effect of recombinant AMWAP (20 μg/ml) on peptidase activities of the 20S proteasome was assayed using luminogenic cleavage assays with the substrates Z-LRR-aminoluciferin (trypsin-like activity) (A), Suc-LLVY-aminoluciferin (chymotrypsin-like activity) (B), and Z-nLPnLD-aminoluciferin (caspase-like activity) (C). Data show mean ± SD (n = 4/group) with *P < 0.05, **P < 0.01, ***P < 0.001 for treatment vs. control. MG-132 (1 μM), a potent 20S proteasome inhibitor, served as a positive control that reduced all three peptidase activities. PBS served as a vehicle control. MG-132, Z-Leu-Leu-Leu-al.