Pancreatic trypsin inhibitor Kunitz domain (IPR002223)

Short name: Kunitz_BPTI

Domain relationships



The majority of the sequences having this domain belong to the MEROPS inhibitor family I2, clan IB; the Kunitz/bovine pancreatic trypsin inhibitor family, they inhibit proteases of the S1 family [PMID: 14705960] and are restricted to the metazoa with a single exception: Amsacta moorei entomopoxvirus. They are short (~50 residue) alpha/beta proteins with few secondary structures. The fold is constrained by 3 disulphide bonds. The type example for this family is aprotinin (bovine pancreatic trypsin inhibitor) [PMID: 1714504] (or basic protease inhibitor), but the family includes numerous other members [PMID: 1703675, PMID: 1593645, PMID: 8159751, PMID: 1304909], such as snake venom basic protease; mammalian inter-alpha-trypsin inhibitors; trypstatin, a rodent mast cell inhibitor of trypsin; a domain found in an alternatively-spliced form of Alzheimer's amyloid beta-protein; domains at the C-termini of the alpha(1) and alpha(3) chains of type VII and type VI collagens; and tissue factor pathway inhibitor precursor.

The pancreatic trypsin inhibitor (Kunitz) family [PMID: 6996568, PMID: 1703675, PMID: 1593645] is one of the numerous families of serine proteinase inhibitors. The basic structure of such a type of inhibitor is shown in the following schematic representation:

            |  +--------+           |
            |  |      **|*******    |
                    |          |

            {------50 residues------}

'C': conserved cysteine involved in a disulfide bond.
'#': active site residue.
'*': position of the pattern.

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0004867 serine-type endopeptidase inhibitor activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PROSITE profiles