1aep
From Proteopedia
(New page: 200px<br /><applet load="1aep" size="450" color="white" frame="true" align="right" spinBox="true" caption="1aep, resolution 2.7Å" /> '''MOLECULAR STRUCTURE O...) |
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| - | [[Image:1aep.jpg|left|200px]]<br /><applet load="1aep" size=" | + | [[Image:1aep.jpg|left|200px]]<br /><applet load="1aep" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1aep, resolution 2.7Å" /> | caption="1aep, resolution 2.7Å" /> | ||
'''MOLECULAR STRUCTURE OF AN APOLIPOPROTEIN DETERMINED AT 2.5-ANGSTROMS RESOLUTION'''<br /> | '''MOLECULAR STRUCTURE OF AN APOLIPOPROTEIN DETERMINED AT 2.5-ANGSTROMS RESOLUTION'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The three-dimensional structure of an apolipoprotein isolated from the | + | The three-dimensional structure of an apolipoprotein isolated from the African migratory locust Locusta migratoria has been determined by X-ray analysis to a resolution of 2.5 A. The overall molecular architecture of this protein consists of five long alpha-helices connected by short loops. As predicted from amino acid sequence analyses, these helices are distinctly amphiphilic with the hydrophobic residues pointing in toward the interior of the protein and the hydrophilic side chains facing outward. The molecule falls into the general category of up-and-down alpha-helical bundles as previously observed, for example, in cytochrome c'. Although the structure shows the presence of five long amphiphilic alpha-helices, the alpha-helical moment and hydrophobicity of the entire molecule fall into the range found for normal globular proteins. Thus, in order for the amphiphilic helices to play a role in the binding of the protein to a lipid surface, there must be a structural reorganization of the protein which exposes the hydrophobic interior to the lipid surface. The three-dimensional motif of this apolipoprotein is compatible with a model in which the molecule binds to the lipid surface via a relatively nonpolar end and then spreads on the surface in such a way as to cause the hydrophobic side chains of the helices to come in contact with the lipid surface, the charged and polar residues to remain in contact with water, and the overall helical motif of the protein to be maintained. |
==About this Structure== | ==About this Structure== | ||
| - | 1AEP is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Locusta_migratoria Locusta migratoria]. Full crystallographic information is available from [http:// | + | 1AEP is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Locusta_migratoria Locusta migratoria]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1AEP OCA]. |
==Reference== | ==Reference== | ||
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[[Category: lipoprotein]] | [[Category: lipoprotein]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:43:46 2008'' |
Revision as of 09:43, 21 February 2008
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MOLECULAR STRUCTURE OF AN APOLIPOPROTEIN DETERMINED AT 2.5-ANGSTROMS RESOLUTION
Overview
The three-dimensional structure of an apolipoprotein isolated from the African migratory locust Locusta migratoria has been determined by X-ray analysis to a resolution of 2.5 A. The overall molecular architecture of this protein consists of five long alpha-helices connected by short loops. As predicted from amino acid sequence analyses, these helices are distinctly amphiphilic with the hydrophobic residues pointing in toward the interior of the protein and the hydrophilic side chains facing outward. The molecule falls into the general category of up-and-down alpha-helical bundles as previously observed, for example, in cytochrome c'. Although the structure shows the presence of five long amphiphilic alpha-helices, the alpha-helical moment and hydrophobicity of the entire molecule fall into the range found for normal globular proteins. Thus, in order for the amphiphilic helices to play a role in the binding of the protein to a lipid surface, there must be a structural reorganization of the protein which exposes the hydrophobic interior to the lipid surface. The three-dimensional motif of this apolipoprotein is compatible with a model in which the molecule binds to the lipid surface via a relatively nonpolar end and then spreads on the surface in such a way as to cause the hydrophobic side chains of the helices to come in contact with the lipid surface, the charged and polar residues to remain in contact with water, and the overall helical motif of the protein to be maintained.
About this Structure
1AEP is a Single protein structure of sequence from Locusta migratoria. Full crystallographic information is available from OCA.
Reference
Molecular structure of an apolipoprotein determined at 2.5-A resolution., Breiter DR, Kanost MR, Benning MM, Wesenberg G, Law JH, Wells MA, Rayment I, Holden HM, Biochemistry. 1991 Jan 22;30(3):603-8. PMID:1988048
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