Biotin-PEG2-Claudin-3 is derived from the tight junction protein Claudin-3 which is encoded by the CLDN3 gene located on chromosome 7q11.23 and can be found within epithelial cell to cell contacts. Structurally, the Claudin family are transmembrane proteins containing two extracellular loops and are involved in maintaining cell polarity and controlling paracellular ion flux.

During cancer research reduction in the number of Claudins has been associated with tumour formation. This could be explained using Claudin’s role in maintaining cell detachment and migration although cancers such as breast and prostate have shown to overexpress both Claudin- 3 and Claudin-4. Similarly in ovarian cancer overexpression of Claudin 3 and 4 is thought to increase the motility of tumour cells and their survival through basement membrane degrading matrix metalloproteinase activation.

Both Claudin 3 and 4 have potential to be used as diagnostic markers and their two extracellular loops may be used as targets for antibodies. As receptors for the Clostridium perfringens enterotoxin, Claudin 3 and 4 may have further use in targeting the enterotoxin as a therapeutic for ovarian cancers.

This peptide has a covalently bonded N-terminal Biotin tag that can be used for detection and purification and contains a polyethylene glycol spacer (PEG2).