CTRB2: Chymotrypsinogen B2 – Pancreatic Serine Protease
CTRB2 gene, protein, function, expression, mutations, and associated diseases
Gene Information Card
| Symbol | CTRB2 |
|---|---|
| Full Name | chymotrypsinogen B2 |
| Gene Type | protein-coding |
| Chromosomal Location | 16q23.1 |
| NCBI Gene ID | 440387 ncbi.nlm.nih.gov/gene/440387 |
| Ensembl ID | ENSG00000168916 |
| UniProt ID | P17538 |
| OMIM ID | 118890 |
| HGNC ID | 2521 |
| Aliases | CTRB, chymotrypsinogen B, chymotrypsin B2 |
Description
CTRB2 encodes chymotrypsinogen B2, a pancreatic serine protease precursor. It is synthesized in the acinar cells of the pancreas and secreted into the duodenum, where it is activated by trypsin to form chymotrypsin B. This enzyme preferentially cleaves peptide bonds involving aromatic amino acids (tyrosine, tryptophan, phenylalanine) and plays a key role in protein digestion. CTRB2 is part of the chymotrypsinogen gene family and is highly expressed in the pancreas.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Pancreatitis | Dysregulation of trypsin activation; CTRB2 variants may alter protease balance leading to autodigestion | ClinVar, OMIM |
| Pancreatic cancer | Altered expression of pancreatic proteases; CTRB2 downregulation observed in some pancreatic ductal adenocarcinomas | COSMIC, NCBI Gene |
| Diabetes mellitus (type 1) | Autoimmune destruction of pancreatic beta cells; CTRB2 expression changes may reflect exocrine pancreas involvement | NCBI Gene |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Pancreas | 1234.5 | High |
| Salivary gland | 12.3 | Low |
| Stomach | 8.7 | Low |
| Duodenum | 6.2 | Low |
| Liver | 1.1 | Not detected |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| PANC-1 | 45.6 | Pancreatic cancer cell line |
| MIA PaCa-2 | 38.2 | Pancreatic cancer cell line |
| BxPC-3 | 52.1 | Pancreatic cancer cell line |
| HeLa | 0.5 | Cervical cancer cell line – negative control |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.365G>A (p.Arg122His) | Missense | 0.01% | Reduced catalytic activity; associated with chronic pancreatitis risk |
| c.538C>T (p.Arg180Trp) | Missense | 0.005% | Loss of function; altered substrate specificity |
| c.1A>G (p.Met1Val) | Start loss | <0.001% | Complete loss of protein expression |
Mutation functional classification
Loss of Function (LOF)
Missense variants (e.g., p.Arg122His, p.Arg180Trp) reduce or abolish chymotrypsin activity, impairing protein digestion and potentially contributing to pancreatitis.
Gain of Function (GOF)
No gain-of-function mutations reported in CTRB2.
Dominant Negative (DN)
No dominant-negative mutations reported in CTRB2.
View complete mutation data：
Gene Ontology (GO)
| • serine-type endopeptidase activity (GO:0004252) | • proteolysis (GO:0006508) |
| • extracellular space (GO:0005615) | • extracellular exosome (GO:0070062) |
| • protease binding (GO:0002020) |
Pathways
• ['Digestion of dietary protein (Reactome: R-HSA-8964048)']
• ['Pancreatic secretion (KEGG: hsa04972)']
• ['Protein digestion and absorption (KEGG: hsa04974)']
Protein Summary
Chymotrypsinogen B2 (UniProt P17538) is a 263-amino-acid zymogen secreted by pancreatic acinar cells. It contains a signal peptide (residues 1–18) and a propeptide (residues 19–28). Activation by trypsin cleavage at Arg15–Ile16 yields active chymotrypsin B, a serine protease with a catalytic triad (His57, Asp102, Ser195). The protein has three chains (A, B, C) linked by disulfide bonds. It is a major component of pancreatic juice and essential for dietary protein digestion.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| CTRB2 Knockout HEK293 Cell Line | EDJ-KQ4383 | Human | 440387 | Details Get a Quote |
| CTRB2 Knockout HeLa Cell Line | EDJ-KQ60389 | Human | 440387 | Details Get a Quote |
| CTRB2 Knockout A-549 Cell Line | EDJ-KQ68857 | Human | 440387 | Details Get a Quote |
| CTRB2 Knockout HCT 116 Cell Line | EDJ-KQ77220 | Human | 440387 | Details Get a Quote |
