The insulin-like growth factor binding proteins (IGFBPs) play a major role in the regulation of the effects and the bioavailability of the insulin-like growth factors (IGFs). IGFs are released from IGFBP−IGF complexes by proteolysis of IGFBPs generating fragments with reduced ligand-binding properties. To identify naturally occurring fragments of IGFBP-2, a peptide library generated from human hemofiltrate was immunologically screened. Purification of immunoreactive IGFBP-2 fragments was performed by consecutive chromatographic steps. A total of 18 different IGFBP-2 fragments was isolated and characterized.
