Structural highlights
Function
IBP4_HUMAN IGF-binding proteins prolong the half-life of the IGFs and have been shown to either inhibit or stimulate the growth promoting effects of the IGFs on cell culture. They alter the interaction of IGFs with their cell surface receptors.
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Insulin-like growth factor binding proteins (IGFBPs) control the extracellular distribution, function, and activity of IGFs. Here, we report an X-ray structure of the binary complex of IGF-I and the N-terminal domain of IGFBP-4 (NBP-4, residues 3-82) and a model of the ternary complex of IGF-I, NBP-4, and the C-terminal domain (CBP-4, residues 151-232) derived from diffraction data with weak definition of the C-terminal domain. These structures show how the IGFBPs regulate IGF signaling. Key features of the structures include (1) a disulphide bond ladder that binds to IGF and partially masks the IGF residues responsible for type 1 IGF receptor (IGF-IR) binding, (2) the high-affinity IGF-I interaction site formed by residues 39-82 in a globular fold, and (3) CBP-4 interactions. Although CBP-4 does not bind individually to either IGF-I or NBP-4, in the ternary complex, CBP-4 contacts both and also blocks the IGF-IR binding region of IGF-I.
Structural basis for the regulation of insulin-like growth factors by IGF binding proteins.,Siwanowicz I, Popowicz GM, Wisniewska M, Huber R, Kuenkele KP, Lang K, Engh RA, Holak TA Structure. 2005 Jan;13(1):155-67. PMID:15642270[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Siwanowicz I, Popowicz GM, Wisniewska M, Huber R, Kuenkele KP, Lang K, Engh RA, Holak TA. Structural basis for the regulation of insulin-like growth factors by IGF binding proteins. Structure. 2005 Jan;13(1):155-67. PMID:15642270 doi:10.1016/j.str.2004.11.009
