PZP
Function
Is able to inhibit all four classes of proteinases by a unique 'trapping' mechanism. This protein has a peptide stretch, called the 'bait region' which contains specific cleavage sites for different proteinases. When a proteinase cleaves the bait region, a conformational change is induced in the protein which traps the proteinase. The entrapped enzyme remains active against low molecular weight substrates (activity against high molecular weight substrates is greatly reduced). Following cleavage in the bait region a thioester bond is hydrolyzed and mediates the covalent binding of the protein to the proteinase.
Sequence Similarities
Belongs to the protease inhibitor I39 (alpha-2-macroglobulin) family.
Tissue Specificity
Plasma. Prominent constituent of late-pregnancy sera.
Cellular localization
- Secreted
Alternative names
CPAMD6, PZP, Pregnancy zone protein, C3 and PZP-like alpha-2-macroglobulin domain-containing protein 6