WAP-type 'four-disulfide core' domain (IPR008197)

Short name: WAP_dom

Overlapping homologous superfamilies

Domain relationships



The four-disulfide core (4-DSC) or WAP domain comprises eight cysteine residues involved in disulfide bonds in a conserved arrangement [PMID: 6896234]. The four disulphide core containing Whey Acidic Proteins (WAP) are the major whey proteins in the milk of many mammals and are considered to be the prototypic members of the family. However the WAP domain is not exclusive to WAP proteins, but it is found in many other proteins, a number of which have been shown to exhibit antiproteinase function [PMID: 11965550].

One or more of the WAP domains occur in the WDNM1 protein, which is involved in the metastatic potential of adenocarcinomas in rats [PMID: 3136918]; Kallmann syndrome protein [PMID: 1913827]; caltrin-like protein II from guinea pig [PMID: 2324101], which inhibits calcium transport into spermatozoa; elafin, a serine elastase inhibitor which belongs to MEROPS inhibitor family I17 [PMID: 2394696]; and papilin, a metalloendopeptidase inhibitor which belongs to MEROPS inhibitor family I2 and is effective against procollagen N-proteinase [PMID: 11076767].

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

GO:0030414 peptidase inhibitor activity

Cellular Component

GO:0005576 extracellular region

Contributing signatures

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