Abcam, ab65300, Cathepsin B Activity Assay Kit (Fluorometric)

Size: 100Test
Cathepsin B Activity Assay Kit (Fluorometric) ab65300 is an easy and convenient assay for the detection of Cathepsin B activity. Based on an Ac-RR-AFC substrate; cleavage by Cathepsin B releases fluorescent AFC. Readout with any fluorometric (Ex/Em 400/505 nm) plate reader. - Cited in > 90 publications Individual kit components also available for purchase with a minimum order of 20 units. Contact us to discuss your needs.
Key facts
Detection method:Fluorescent,
Sample types:Tissue Extracts, Cell Lysate,
Assay type:Semi-quantitative,
Assay time:2h,
Assay Platform:Microplate reader

Product details:
How the assay works
Cathepsin B Activity Assay Kit (Fluorometric) utilizes the preferred cathepsin-B substrate sequence RR labeled with AFC (amino-4-trifluoromethyl coumarin).
Cell lysates or other samples that contain cathepsin-B will cleave the synthetic substrate RR-AFC to release free AFC. The released AFC can easily be quantified using a fluorometer or fluorescence plate reader at Ex/Em 400/505 nm.
Cathepsin B Activity Assay Kit protocol summary:
Prepare samples
- Add Cathepsin B Reaction Buffer/reaction buffer
- Add Ac-RR-AFC substrate
- Incubate for 1 -2 hours at 37°C
- Measure fluorescence (Ex/Em = 400/505 nm)
Related and recommended products
See below other alternative Cathepsin Assay Kits:
- Cathepsin L Assay Kit (Magic Red)
ab270774
- Cathepsin K Assay Kit (Magic Red)
ab270773
This product is manufactured by BioVision, an Abcam company and was previously called K140 Cathepsin B Activity Fluorometric Assay Kit. K140-100 is the same size as the 100 test size of ab65300.
The Safety Datasheet for this product has been updated for certain countries. Please check the current version in the Support and downloads section.

Properties and Storage Information:
Shipped at conditions-Blue Ice, Appropriate short-term storage conditions--20°C, Appropriate long-term storage conditions--20°C, Storage information--20°C

Supplementary Information:
This supplementary information is collated from multiple sources and compiled automatically.
Cathepsin B also known as CTSB or cathepsin beta is a lysosomal cysteine protease belonging to the papain family. This enzyme possesses a molecular weight of approximately 25 to 30 kDa. You can find cathepsin B expressed in various tissues with high levels observed in the liver kidney and spleen. It plays a mechanical role in protein degradation within lysosomes operating optimally in acidic environments. The enzyme has active and inactive forms depending on structural modifications and environmental conditions.
Biological function summary
Cathepsin B participates as a proteolytic enzyme involved in protein turnover and processing. It does not function in isolation but often associates with various other proteases forming complexes essential for efficient substrate breakdown. Cathepsin B assists in the activation of other enzymes by cleaving propeptides therefore facilitating the initiation of cascade reactions. This role is critical in maintaining cellular homeostasis and modulating physiological processes including cell migration and immune response modulation.
Pathways
Cathepsin B significantly contributes to the lysosomal protein degradation pathway and the autophagy-lysosome pathway. It interacts with proteins such as B protein which are important for cellular recycling and energy homeostasis. Its activity supports the MHC class II antigen processing pathway playing an essential part in immune system functionality. Cathepsin B also exhibits interactions with Ctsb protein inhibitors which regulate its proteolytic activity within these pathways.
Cathepsin B has strong associations with cancer progression and neurological disorders such as Alzheimer's disease. Its overexpression and dysregulation are linked to tumor metastasis where it degrades extracellular matrix components promoting invasion. Ctsb protein interactions with corey mazo proteins influence tumor microenvironment and immune evasion. In Alzheimer's disease cathepsin B can influence amyloid beta peptide processing connected to neurodegenerative pathology progression. These roles highlight the potential for cathepsin B as a therapeutic target in addressing these conditions.