CTSB

What is CTSB?

Cathepsin B (CTSB) is a lysosomal endo- and exopeptidase in humans that is encoded by the CTSB gene. CTSB belongs to papain superfamily. It is originally synthesized as an inactive pre-procathepsin B, which matures via multiple procedures, including the co-translational removal of the pre-peptide, translocation to Golgi-apparatus for the cleavage of the pro-part, and the glycosylation of the mature form. The mature CTSB is transported to the lysosome through the M6P (mannose-6-phosphate). It is widely expressed in various tissues and cells, including in the brain.

What is the feature of the CTSB structure?

CTSB is bilobal in shape, with a catalytic site located at the interface between the two lobes. The catalytic region is a triad composed of the amino acids cysteine, histidine, and aspartic acid, and the interaction between cysteine on the left lobe and histidine on the right lobe catalyzes peptide bond cleavage. Different from other cathepsins, CTSB contains an 18 amino acid occluding loop lying between Pro107 and Asp124. Two salt bridges between the occluding and the mature enzyme partially block the substrate-binding cleft, thus promoting its peptidyldipeptidase activity.

What is the function of the CTSB?

In terms of coronavirus entry into the host cell, CTSB facilitates the activation of spike glycoprotein in the endosomal pathway.

As a lysosomal protease, CTSB is involved in several cellular degradation processes such as the degradation of protein ＆ extracellular matrix, regulatory mechanisms, apoptosis, autophagy, and antigen representation. CTSB is also implicated in the pathology of chronic inflammatory diseases of airways and joints, cancer, and pancreatitis. CTSB has been proposed as a potentially effective biomarker for various cancers. Overexpression of CTSB is correlated with invasive and metastatic cancers. Recent studies show that CTSB executes other cellular programs such as controlling tumor growth, migration, invasion, angiogenesis, and metastases development. Moreover, the level of CTSB transcription and expression is positively correlated with the prognosis of the tumor.

Hot products of CTSB:

Recombinant Human Cathepsin B (CTSB), partial (Active) (C-terminal 6xHis-tagged) (CSB-AP005381HU)

Recombinant Human Cathepsin B (CTSB), partial (N-terminal GST-tagged) (CSB-EP006185HU1)

CTSB Antibody (ELISA, WB, IHC, IF) (CSB-PA06974A0Rb)

Human cathepsin B (CTSB) ELISA kit (CSB-E13450h)