HAMLET inhibits proteasome activity.

<p>(A) Proteasome activity was monitored <i>in vitro</i> as chymotrypsin-dependent suc-LLVY-AMC cleavage (50 µM) over time and MG132 was used as proteasome inhibitor. Except for the first 10 minutes HAMLET reduced proteasome activity compared to the control. (B) Inhibition of proteasome activity in A549 cells. Cytoplasmic extracts were prepared from cells treated with HAMLET or native α-lactalbumin (34 µM) after 1, 3 and 6 hours of incubation and enzymatic activity was quantified by suc-LLVY-AMC cleavage (50 µM). MG132 was used to inhibit proteasome function.