Selective and Sensitive Monitoring of Caspase-1 Activity by a Novel Bioluminescent Activity-Based Probe
摘要:
The role of caspase-1 in inflammation has been studied intensely over recent years. However, the research of caspase-1 has remained difficult mainly due to the lack of sensitive and selective tools to monitor not only its abundance but also its activity. Here we present a bioluminescent activity-based probe (ABP) for caspase-1, developed by the Reverse Design concept, where chemically optimized protease inhibitors are turned into selective substrate ABPs. The probe exhibits excellent selectivity for caspase-1 and similar to 1000-fold increase in sensitivity compared to available fluorogenic peptidic caspase-1 substrates. Moreover, we have been able to monitor and quantify specific caspase-1 activity directly in cell lysates. The activity correlated well with processing of prointerleukin-1 beta and prointerleukin-18 in phorbol 12-myristate 13-acetate (PMA)-stimulated cells. A detectable caspase-1 activity was present also in nonstimulated cells, consistent with processing of constitutively expressed prointerleukin-18.
The present invention relates to molecular probes of formula (I)
L1-R1-L}
n
-A-CO—NH—R2-L2 (I)
as defined herein that allow for the observation of the catalytic activity of a selected caspase in in vitro assays, in cells or in multicellular organisms, a method for their preparation and the use thereof.