IGFBP-4 Human Recombinant amino acids Asp22- Glu258, produced in HEK293 cells and fused with a polyhistidine tag at the C-terminus. IGFBP4 predicted Mw is 27kDa and on SDS-PAGE appears as a 32kDa band under denaturing conditions.
IGFBP4 is purified by proprietary chromatographic techniques.
Insulin-like growth factor-binding protein 4 (IGFBP-4) belongs to the insulin-like growth factor binding protein (IGFBP) family. IGFBP4 includes an IGFBP domain and a thyroglobulin type-I domain. IGFBP4 binds both insulin-like growth factors (IGFs) I and II. IGFBP-4 circulates in the plasma in both glycosylated and non-glycosylated forms. IGFBPs can either inhibit or enhance the biological activities of IGF, or act in an IGF independent manner. IGFBP-4 is exceptional since it consistently inhibits several cancer cells in vivo and in vitro, suggesting that it may function as an apoptotic factor. IGFBP4 is produced by all colon cancer cells. Binding of IGFBP-4 prolongs the half-life of the IGFs and changes their interaction with cell surface receptors.
