Figure 4.

Chymotrypsin-like activity of the proteasome is increased in cardiac muscle of diabetic mice. The chymotrypsin-like activity was measured using the fluorogenic substrate LLVY-amc, with or without the proteasome inhibitor epoxomicin (20 μm) in control (Ctrl), diabetic (STZ), or insulin-treated diabetic (STZ+Ins) mice. The difference between activity in the presence and absence of inhibitor was used to calculate proteasome activity. Data are reported as the means ± se (n = 6 per group). *, P < 0.05 vs. control.