Suc-Leu-Leu-Val-Tyr-AMC

Suc-Leu-Leu-Val-Tyr-AMC (Suc-LLVY) is a membrane-permeable calpain-specific fluorogenic substrate, pteolytic hydrolysis of the peptidyl-7-amino bond liberates the highly fluorescent 7-amino-4-methylcoumarin (AMC) moiety. The effect of TGF-β on hydrolysis of these substrates (e.g Suc-Leu-Leu-Val-Tyr-AMC) are assessed. Biliary epithelial H69 cells are incubated with 10, 1, 0.1, or 0 ng/mL TGF-β for 24 h. Substrate hydrolysis is then fluorometrically assessed in cytosolic extracts. Basal activity is 1.12, 8.33, and 14.52 nmol AMC/mg protein/min for suc-LLVY-AMC, z-LLE-AMC, and z-LLL-AMC hydrolysis, respectively.