1gw3
From Proteopedia
(New page: 200px<br /> <applet load="1gw3" size="450" color="white" frame="true" align="right" spinBox="true" caption="1gw3" /> '''THE HELIX-HINGE-HELIX STRUCTURAL MOTIF IN H...) |
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'''THE HELIX-HINGE-HELIX STRUCTURAL MOTIF IN HUMAN APOLIPOPROTEIN A-I DETERMINED BY NMR SPECTROSCOPY, 1 STRUCTURE'''<br /> | '''THE HELIX-HINGE-HELIX STRUCTURAL MOTIF IN HUMAN APOLIPOPROTEIN A-I DETERMINED BY NMR SPECTROSCOPY, 1 STRUCTURE'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The conformation of a synthetic peptide of 46 residues from apoA-I was | + | The conformation of a synthetic peptide of 46 residues from apoA-I was investigated by fluorescence, CD, and 2D NMR spectroscopies in lipid-mimetic environments. ApoA-I(142-187) is mainly unstructured in water but helical in SDS or dodecylphosphocholine (DPC), although the peptide only associates with DPC at approximately the critical micellar concentration. Solution structures of apoA-I(142-187) were determined by distance geometry calculations based on 450 (in DPC-d38) or 397 (in SDS-d25) NOE-derived distance restraints, respectively. Backbone RMSDs for superimposing the two helical regions 146-162 and 168-182 are 0.98 +/- 0.22 (2.38 +/- 0.20) and 1.99 +/- 0.42 (2.02 +/- 0.21) A in DPC (SDS), respectively. No interhelical NOE was found, suggesting that helix-helix interactions between the two helical domains in apoA-I(142-187) are unlikely. Similar average, curved helix-hinge-helix structures were found in both SDS and DPC micelles with the hydrophobic residues occupying the concave face, indicating that hydrophobic interactions dominate. Intermolecular NOESY experiments, performed in the presence of 50% protonated SDS, confirm that the two amphipathic helices and Y166 in the hinge all interact with the micelle. The involvement of Y166 in lipid binding is supported by fluorescence spectroscopy as well. On the basis of all the data above, we propose a model for the peptide-lipid complexes wherein the curved amphipathic helix-hinge-helix structural motif straddles the micelle. The peptide-aided signal assignment achieved for apoA-I(122-187) (66mer) and apoA-I suggests that such a structural motif is retained in the longer peptide and most likely in the intact protein. |
==Disease== | ==Disease== | ||
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==About this Structure== | ==About this Structure== | ||
| - | 1GW3 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:// | + | 1GW3 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=1GW3 OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Homo sapiens]] | [[Category: Homo sapiens]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Cushley, R | + | [[Category: Cushley, R J.]] |
| - | [[Category: Sparrow, J | + | [[Category: Sparrow, J T.]] |
[[Category: Wang, G.]] | [[Category: Wang, G.]] | ||
[[Category: amphipathic helices]] | [[Category: amphipathic helices]] | ||
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[[Category: receptor binding]] | [[Category: receptor binding]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:54:36 2008'' |
Revision as of 10:54, 21 February 2008
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THE HELIX-HINGE-HELIX STRUCTURAL MOTIF IN HUMAN APOLIPOPROTEIN A-I DETERMINED BY NMR SPECTROSCOPY, 1 STRUCTURE
Contents |
Overview
The conformation of a synthetic peptide of 46 residues from apoA-I was investigated by fluorescence, CD, and 2D NMR spectroscopies in lipid-mimetic environments. ApoA-I(142-187) is mainly unstructured in water but helical in SDS or dodecylphosphocholine (DPC), although the peptide only associates with DPC at approximately the critical micellar concentration. Solution structures of apoA-I(142-187) were determined by distance geometry calculations based on 450 (in DPC-d38) or 397 (in SDS-d25) NOE-derived distance restraints, respectively. Backbone RMSDs for superimposing the two helical regions 146-162 and 168-182 are 0.98 +/- 0.22 (2.38 +/- 0.20) and 1.99 +/- 0.42 (2.02 +/- 0.21) A in DPC (SDS), respectively. No interhelical NOE was found, suggesting that helix-helix interactions between the two helical domains in apoA-I(142-187) are unlikely. Similar average, curved helix-hinge-helix structures were found in both SDS and DPC micelles with the hydrophobic residues occupying the concave face, indicating that hydrophobic interactions dominate. Intermolecular NOESY experiments, performed in the presence of 50% protonated SDS, confirm that the two amphipathic helices and Y166 in the hinge all interact with the micelle. The involvement of Y166 in lipid binding is supported by fluorescence spectroscopy as well. On the basis of all the data above, we propose a model for the peptide-lipid complexes wherein the curved amphipathic helix-hinge-helix structural motif straddles the micelle. The peptide-aided signal assignment achieved for apoA-I(122-187) (66mer) and apoA-I suggests that such a structural motif is retained in the longer peptide and most likely in the intact protein.
Disease
Known diseases associated with this structure: Amyloidosis, 3 or more types OMIM:[107680], ApoA-I and apoC-III deficiency, combined OMIM:[107680], Corneal clouding, autosomal recessive OMIM:[107680], Hypertriglyceridemia, one form OMIM:[107680], Hypoalphalipoproteinemia OMIM:[107680]
About this Structure
1GW3 is a Single protein structure of sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
The helix-hinge-helix structural motif in human apolipoprotein A-I determined by NMR spectroscopy., Wang G, Sparrow JT, Cushley RJ, Biochemistry. 1997 Nov 4;36(44):13657-66. PMID:9354635
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