IGFBP-3 peptide is a peptide derived from the nuclear localization sequence within the heparin-binding domain of insulin like growth factor binding protein-3 (IGFBP-3), and corresponds to amino acids 215-232 of the full length protein. Both this region and IGFBP-3 peptide bind to glycosaminoglycans including hyaluronan, and also have high affinity and specificity for the mitochondria derived peptide humanin, binding to it with a with a Kd of 120 nM compared with binding of 101 nM for the full-length protein. Both the IGFBP-3 protein and the synthetic IGFBP-3 peptide bind to hyaluronic acid and block its ability to interact with its receptor CD44, and using the synthetic IGFBP-3 peptide to bind hyaluronan inhibits viability of A549 lung cancer cells, an effect correlated with increased apoptosis.
