1boe
From Proteopedia
(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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'''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'''<br /> | '''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'''<br /> | ||
==Overview== | ==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 | + | 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== | ==About this Structure== | ||
| - | 1BOE is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http:// | + | 1BOE is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1BOE OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Georgescu, J.]] | [[Category: Georgescu, J.]] | ||
[[Category: Grol, M.]] | [[Category: Grol, M.]] | ||
| - | [[Category: Holak, T | + | [[Category: Holak, T H.]] |
[[Category: Kalus, W.]] | [[Category: Kalus, W.]] | ||
[[Category: Lang, K.]] | [[Category: Lang, K.]] | ||
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[[Category: nmr]] | [[Category: nmr]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:57:27 2008'' |
Revision as of 09:57, 21 February 2008
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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
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