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. Author manuscript; available in PMC: 2009 Sep 1.
Published in final edited form as: Mech Ageing Dev. 2008 Apr 30;129(9):515–521. doi: 10.1016/j.mad.2008.04.007

Figure 2. Analysis of heart lysate reveals an age-related impairment in 20S, and age-related increase in 26S, proteasome activity.

Figure 2

Analysis of 26S proteasome activity in heart lysates (ATP stimulated) revealed a significant elevation in chymotrypsin-like activity in both aged and DR heart lysates. Analysis of 20S proteasome activity (SDS stimulated) revealed an age-related impairment in chymotrypsin-like activity in 25-month old tissues relative to heart lysates from 3-month old animals. The specificity for proteasome activity in heart lysate studies was determined by subtracting the background protease activity (chymotrypsin-like activity not inhibited by lysate pretreatment with 10 μM MG132). *p < 0.05 compared to 3 month old AL animals.