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1boe
From Proteopedia
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(New page: 200px<br /> <applet load="1boe" size="450" color="white" frame="true" align="right" spinBox="true" caption="1boe" /> '''STRUCTURE OF THE IGF BINDING DOMAIN OF THE ...)
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Revision as of 14:06, 12 November 2007
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STRUCTURE OF THE IGF BINDING DOMAIN OF THE INSULIN-LIKE GROWTH FACTOR-BINDING PROTEIN-5 (IGFBP-5): IMPLICATIONS FOR IGF AND IGF-I RECEPTOR INTERACTIONS
Overview
Binding proteins for insulin-like growth factors (IGFs) IGF-I and IGF-II, known as IGFBPs, control the distribution, function and activity of IGFs, in various cell tissues and body fluids. Insulin-like growth, factor-binding protein-5 (IGFBP-5) is known to modulate the stimulatory, effects of IGFs and is the major IGF-binding protein in bone tissue. We, have expressed two N-terminal fragments of IGFBP-5 in Escherichia coli;, the first encodes the N-terminal domain of the protein (residues 1-104), and the second, mini-IGFBP-5, comprises residues Ala40 to Ile92. We show, that the entire IGFBP-5 protein contains only one high-affinity binding, site for IGFs, located in mini-IGFBP-5. The solution structure of, mini-IGFBP-5, determined by nuclear magnetic resonance spectroscopy, discloses a rigid, globular structure that consists of a centrally located, three-stranded anti-parallel beta-sheet. Its scaffold is stabilized, further by two inside packed disulfide bridges. The binding to IGFs, which, is in the nanomolar range, involves conserved Leu and Val residues, localized in a hydrophobic patch on the surface of the IGFBP-5 protein., Remarkably, the IGF-I receptor binding assays of IGFBP-5 showed that, IGFBP-5 inhibits the binding of IGFs to the IGF-I receptor, resulting in, reduction of receptor stimulation and autophosphorylation. Compared with, the full-length IGFBP-5, the smaller N-terminal fragments were less, efficient inhibitors of the IGF-I receptor binding of IGFs.
About this Structure
1BOE is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
Structure of the IGF-binding domain of the insulin-like growth factor-binding protein-5 (IGFBP-5): implications for IGF and IGF-I receptor interactions., Kalus W, Zweckstetter M, Renner C, Sanchez Y, Georgescu J, Grol M, Demuth D, Schumacher R, Dony C, Lang K, Holak TA, EMBO J. 1998 Nov 16;17(22):6558-72. PMID:9822601
Page seeded by OCA on Mon Nov 12 16:13:03 2007
