WFDC12 Background Information Peptidases are enzymes that are responsible for hydrolyzing peptide bonds of polypeptide chains during protein catabolism. Protease inhibitors are important peptidase regulators which halt enzymatic function. The WAP (whey acidic protein) domain, also referred to as the WAP-type four-disulfide core domain, is a signature protein motif that contains eight cysteine residues which form disulfide bonds and may exhibit protease inhibitor activity. WAP domain-containing proteins are thought to function in the immune defense by cleaving microbial proteolytic enzymes in order to prevent tissue penetration and infection. WFDC12 (WAP four-disulfide core domain protein 12), also known as WAP2, is a 111 amino acid secreted protein that contains one WAP domain and is highly expressed in lung, esophagus, prostate and skin. A cluster of WAP genes, including WFDC12, exist on chromosome 20, suggesting they evolved by repeated duplications.
