Promega, G8501, Calpain-Glo™ Protease Assay

Simple Protocol Offers Fast, Sensitive Results
The Calpain-Glo™ Protease Assay is a homogeneous, luminescent assay that measures calpain 1 (μ) and 2 (m) activities. Calpains are a family of calcium-activated cysteine proteases involved in cleaving a wide variety of proteins. Calpains modulate the biological activities of their substrates via limited proteolysis.
The Calpain-Glo™ Protease Assay provides a succinyl, proluminescent calpain substrate, Suc-LLVY-aminoluciferin, in a buffer system optimized for calpain and luciferase activities. The addition of the calpain reagent in an "add-mix-measure" format results in calpain cleavage of the substrate and rapid development of a "glow-type" luminescent signal produced by the luciferase reaction. The signal is proportional to the amount of calpain activity present. The assay is designed for use with purified enzyme preparations.
Designed for measuring calpain activity and/or inhibition in a multiwell format and easy to automate.
Well suited for rapidly autolysed enzymes like calpain; maximum sensitivity is reached in as little as 10 minutes, while the enzyme is fully active.
Up to 1,000 times more sensitive than competitive fluorometric assays. The luminescent assay avoids inherent fluorescent background signals, providing excellent signal-to-background readings. The assay is linear over 4 logs of calpain concentration.
Moldoveanu, T. et al. (2002) Cell 108 , 649–60.