In molecular biology, the trappin protein transglutaminase binding domain or cementoin is a protein domain found at the N-terminus of Whey Acidic Protein (WAP) domain-containing protease inhibitors such as trappin-2. This N-terminal domain enables it to become cross-linked to extracellular matrix proteins by transglutaminase.[1] This domain contains several repeated motifs with the consensus sequence Gly-Gln-Asp-Pro-Val-Lys, and these together can anchor the whole molecule to extracellular matrix proteins, such as laminin, fibronectin, beta-crystallin, collagen IV, fibrinogen, and elastin, by transglutaminase-catalysed cross-links. The whole domain is rich in glutamine and lysine, thus allowing transglutaminase(s) to catalyse the formation of an intermolecular epsilon-(gamma-glutamyl)lysine isopeptide bond.[2]
| Cementoin | |||||||||
|---|---|---|---|---|---|---|---|---|---|
 solution structure of r-elafin, a specific inhibitor of elastase, nmr, 11 structures | |||||||||
| Identifiers | |||||||||
| Symbol | Cementoin | ||||||||
| Pfam | PF10511 | ||||||||
| InterPro | IPR019541 | ||||||||
| |||||||||
References
edit- ^ Schalkwijk J, Wiedow O, Hirose S (June 1999). "The trappin gene family: proteins defined by an N-terminal transglutaminase substrate domain and a C-terminal four-disulphide core". Biochem. J. 340 (3): 569–77. doi:10.1042/0264-6021:3400569. PMC 1220286. PMID 10359639.
- ^ Moreau T, Baranger K, Dade S, Dallet-Choisy S, Guyot N, Zani ML (February 2008). "Multifaceted roles of human elafin and secretory leukocyte proteinase inhibitor (SLPI), two serine protease inhibitors of the chelonianin family". Biochimie. 90 (2): 284–95. doi:10.1016/j.biochi.2007.09.007. PMID 17964057.