Description General description Cell-permeable cysteine protease inhibitor. Inhibits cathepsin B (k2/Ki = 8.9 x 103 M-1 sec-1), cathepsin L (k2/Ki = 3.8 x 105 M-1 sec-1), cathepsin S (k2/Ki = 4.2 x 104 M-1 sec-1), and papain (k2/Ki = 2.4 x 103 M-1 sec-1). Cysteine protease inhibitor. Selectively inhibits cathepsin B (k2/Ki = 8.9 x 103 M-1sec-1), cathepsin L (k2/Ki = 3.8 x 105 M-1sec-1), cathepsin S (k2/Ki = 4.2 x 104 M-1sec-1), and papain (k2/Ki = 2.4 x 103 M-1sec-1). Half-life in buffered solution (pH 5-9) = 25 h (30°C); 300 h (0°C). Half-life in buffered solution (pH 5-9) = 25 h (30°C); 300 h (0°C). Packaging 1 mg in Plastic ampoule Biochem/physiol Actions Cell permeable: yes Primary Target cathepsin B Product does not compete with ATP. Reversible: no k₂/Ki = 8.9 x 10³ M⁻¹sec⁻¹ for cathepsin B Warning Toxicity: Standard Handling (A) Sequence Z-Phe-Gly-NHO-Bz Reconstitution Following reconstitution, aliquot and freeze (-20°C). Stock solutions are stable for up to 3 months at -20°C. Other Notes Zhu, D. and Uckun, F.M. 2000. Clin. Cancer Res.6, 2064. Demuth, H.-U., et al. 1996. Biochim. Biophys. Acta 1295, 179. Brömme, D., and Demuth, H.-U. 1994. Methods Enzymol. 244, 671.