Biological Activity: Fully biologically active when compared to standard. The ED50 as determined by its ability to inhibit the cell growth of Mv1Lu mink lung epithelial cells is less than 3.0 μg/mL, corresponding to a specific activity of > 333 IU/mg.
Relevance: Appears to regulate cell growth through interactions with the extracellular matrix and cytokines. Binds calcium and copper, several types of collagen, albumin, thrombospondin, PDGF and cell membranes. There are two calcium binding sites, an acidic domain that binds 5 to 8 Ca(2+) with a low affinity and an EF-hand loop that binds a Ca(2+) ion with a high affinity. Synonyms: Basement-membrane protein 40, Osteonectin, ON, Secreted protein acidic and rich in cysteine,