Cathepsin B

Expression system: E. coli
Length: 82-333, Partial
Activity: Not Tested

Expression system: HEK293 Cells
Length: 18-339, Full Length of Mature Protein
Activity: Enzyme activity

Cathepsin B Protein, Mouse, Recombinant (His) is expressed in HEK293 mammalian cells with His tag. The predicted molecular weight is 36.6 kDa and the accession number is P10605.

Cathepsin B Protein, Rat, Recombinant (His) is expressed in HEK293 mammalian cells with His tag. The predicted molecular weight is 37.1 kDa and the accession number is F7FAT8.

Expression system: E. coli
Length: 21-247, Full Length of Mature Protein
Activity: Not Tested

Cathepsin E (CTSE) is a gastric aspartyl protease that functions as a disulfide-linked homodimer. It is a member of the Peptidase C1 family, and has a specificity similar to that of Pepsin A and Cathepsin D. CTSE is localized to the endoplasmic reticulum and Golgi apparatus, while the mature enzyme is localized to the endosome. It is expressed abundantly in the stomach, the Clara cells of the lung and activated B-lymphocytes, and at lower levels in lymph nodes, skin and spleen. CTSE is an intracellular proteinase that have a role in immune function, activation-induced lymphocyte depletion in the thymus, neuronal degeneration and glial cell activation in the brain. Futhermore, it probably involved in the processing of antigenic peptides during MHC class II-mediated antigen presentation.

β Galactosidase is a lysosomal β Galactosidase that hydrolyzes the terminal β Galactose from Ganglioside and Keratan sulfate. In lysosome, the mature β Galactosidase protein associates with Cathepsin A and Neuraminidase 1 to form the lysosomal multienzyme complex . An alternative splicing at the RNA level of β Galactosidase results a catalytically inactive β Galactosidase that plays an important role in vascular development. Defects of β-galactosidase (GLB1) are the cause of diseases like GM1-gangliosidosis which is a lysosomal storage disease and Morquio Syndrome B that cause patients to have abnormal elastic fibers. More than 100 mutations have been identified for β Galactosidase, which result in different residual activities of the mutant enzymes and a spectrum of symptoms in the two related diseases.

Cystatin-S, also known as Cystatin-4, Salivary acidic protein 1, Cystatin-SA-III and CST4, is a secreted protein which belongs to thecystatin family. Cystatin-4 CST4 is expressed in submandibular and sublingual saliva but not in parotid saliva (at protein level). It is also expressed in saliva, tears, urine and seminal fluid. The cystatin superfamily encompasses proteins that contain multiple cystatin-like sequences. Some of the members are active cysteine protease inhibitors, while others have lost or perhaps never acquired this inhibitory activity. There are three inhibitory families in the superfamily, including the type 1 cystatins (stefins), type 2 cystatins and the kininogens. The type 2 cystatin proteins are a class of cysteine proteinase inhibitors found in a variety of human fluids and secretions. Cystatin-4 CST4 strongly inhibits papain and ficin, partially inhibits stem bromelain and bovine cathepsin C, but does not inhibit porcine cathepsin B or clostripain. Papain is inhibited non-competitively. Cystatin-4 CST4 is an S-type cystatin, based on its high level of expression in saliva, tears and seminal plasma. The specific role in these fluids is unclear but antibacterial and antiviral activity is present, consistent with a protective function.