Caspase-8 Chromogenic Substrate, Ac-IETD-pNA

Ac-IETD-pNA is a chromogenic tetrapeptide substrate used to measure IETD-preferring caspase activity, particularly caspase-8. Proteolytic cleavage releases p-nitroaniline, which can be monitored spectrophotometrically near 405-408 nm. The IETD motif is associated with initiator-caspase recognition and is also processed by granzyme B under appropriate conditions.

• caspase-8 activity assays
• death-receptor apoptosis research
• granzyme B substrate studies
• caspase inhibitor screening

IETD cleavage is not absolutely unique to caspase-8. Use purified enzymes or pathway-specific inhibitors when distinguishing caspase-8 from other IETD-cleaving proteases.

1. Substrate and inhibitor specificity of interleukin-1β-converting enzyme and related caspases
2. A combinatorial approach defines specificities of members of the caspase family and granzyme B