IGFBP7

Insulin-like growth factor-binding protein 7 is a protein that in humans is encoded by the IGFBP7 gene. The major function of the protein is the regulation of availability of insulin-like growth factors (IGFs) in tissue as well as in modulating IGF binding to its receptors. IGFBP7 binds to IGF with low affinity compared to IGFBPs 1-6. It also stimulates cell adhesion. The protein is implicated in some cancers.

== Structure == The edited sites are found within the insulin growth factor binding domain of IGFBP7 and also Heparin binding domain. This region is also a site for proteolytic cleavage. Structural analysis of the edited sites determined that the two amino acids that corresponded to the edited sites are not directly involved in binding to IGF-1 but are found in regions flanking them. At position 78 in unedited version of the transcript there is an Arginine close to residue valine-49. This Valine is important in hydrophobic interaction of Phenylalanine of IGF-1. A substitution to a Glycine at this position is thought to introduce additional flexibility leading to a change of loop conformation, thereby disrupting the hydrophobic interaction that stabilises the complex. At amino acid position 98 the unedited transcript contains a lysine. This residue makes some non specific interactions via the aliphatic part of the side chain with Glu-38 of IGF-1. In the edited version the position is an arginine. The long side chain of which is thought to be able to maintain these weak interactions.