Molecular Weight: 636.28 Salt Form: TFA Purity: >96% Sequence (3-letter): Ac-Leu-Glu-Val-Asp-pNA Sequence (1-letter): Ac-LEVD-pNA Storage: -20 ?C or below Ac-Leu-Glu-Val-Asp-pNA is a colorimetric substrate for Caspase 4. Caspase 4 is a cysteine protease with a poorly defined role in the caspase family. Recent studies have shown it to have a role in inflammation and innate immunity. Like all caspases it cleaves at the Asp residue and prefers the sequence Leu-Glu-Val-Asp. Activity is quantified by the release of p-nitroaniline which is measured by absorbance at 405 nm.