Cathepsin B (CTSB) Assay Kit                                                                                                                                                                         Price

Product Description: Cathepsin B (CTSB) is a lysosomal cysteine protease of the papain family. In vivo studies show that CTSB can function as
both an endopeptidase and exopeptidase. Under normal physiological conditions, CTSB is localized to the lysosomal compartment, and is involved
in turnover of both intracellular and extracellular proteins. However, increased expression and redistribution of CTSB from lysosomes to the cytosol
and extracellular matrix (ECM) can cause protease-induced pathologic changes as observed in traumatic brain injury and Alzheimer’s disease.
The enzyme also directly degrades the ECM at neutral pH, thus promoting migration and invasion of tumor cells. The CTSB activity assay kit is
based on proteolytic hydrolysis of the chromogenic peptide substrate z-Arg-Arg-p-nitroanilide (Neoplasia 10:481, 2008). Cleavage of pNA from the
substrate increases absorbance at 405 nm (extinction coefficient= 9.5 mM-1cm-1) and 410 nm (extinction coefficient= 8.8 mM-1cm-1), allowing for
sensitive and quantitative assay of CTSB activity present in tissue/cell lysates and biological fluids. Kit components are stable for at least 1 year if
stored and handled properly.  

Kit Components:

10x CTSB Buffer: 1 ml, store at 4°C
10x Cell Lysis Solution: 25 ml, store at 4ºC
100x CTSB Substrate: 0.05 ml, store at -20°C (for 100 wells)
100x DTT: 0.1 ml, store at -20°C

MSDS: MES, DTT, pNA, DMSO

Related products: CTSC Assay, DPP-4 Assay, AAP Assay
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HepG2 cells were treated with MG132 to induce
autophagy. The CTSB assay shows the
induction of cathepsin B activity during
autophagy, which is inhibited by E64d, a broad
spectrum cysteine protease inhibitor.