Figure 2. Caspase-like proteasome activity is decreased in the lungs of aged mice. Cleavage of luminogenic model substrates specific for the caspase-like (C-L), chymotrypsin-like (CT-L) or trypsin-like (T-L) active site of the proteasome in lung tissue lysate of (A) C57Bl/6 mice n = 8+SEM and in (B) lung tissue lysate of FVB mice. n = 6-7+SEM.