1rg4
From Proteopedia
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|ACTIVITY= | |ACTIVITY= | ||
|GENE= | |GENE= | ||
| + | |DOMAIN= | ||
| + | |RELATEDENTRY=[[1rg3|1RG3]] | ||
| + | |RESOURCES=<span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1rg4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1rg4 OCA], [http://www.ebi.ac.uk/pdbsum/1rg4 PDBsum], [http://www.rcsb.org/pdb/explore.do?structureId=1rg4 RCSB]</span> | ||
}} | }} | ||
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==Overview== | ==Overview== | ||
Although the membrane-associated surfactant protein B (SP-B) is an essential component of lung surfactant, which is itself essential for life, the molecular basis for its activity is not understood. SP-B's biophysical functions can be partially mimicked by subfragments of the protein, including the C-terminus. We have used NMR to determine the structure of a C-terminal fragment of human SP-B that includes residues 63-78. Structure determination was performed both in the fluorinated alcohol hexafluoro-2-propanol (HFIP) and in sodium dodecyl sulfate (SDS) micelles. In both solvents, residues 68-78 take on an amphipathic helical structure, in agreement with predictions made by comparison to homologous saposin family proteins. In HFIP, the five N-terminal residues of the peptide are largely unstructured, while in SDS micelles, these residues take on a well-defined compact conformation. Differences in helical residue side chain positioning between the two solvents were also found, with better agreement between the structures for the hydrophobic face than the hydrophilic face. A paramagnetic probe was used to investigate the position of the peptide within the SDS micelles and indicated that the peptide is located at the water interface with the hydrophobic face of the helix oriented inward, the hydrophilic face of the helix oriented outward, and the N-terminal residues even farther from the micelle center than those on the hydrophilic face of the alpha-helix. Interactions of basic residues of SP-B with anionic lipid headgroups are known to have an impact on function, and these studies demonstrate structural ramifications of such interactions via the differences observed between the peptide structures determined in HFIP and SDS. | Although the membrane-associated surfactant protein B (SP-B) is an essential component of lung surfactant, which is itself essential for life, the molecular basis for its activity is not understood. SP-B's biophysical functions can be partially mimicked by subfragments of the protein, including the C-terminus. We have used NMR to determine the structure of a C-terminal fragment of human SP-B that includes residues 63-78. Structure determination was performed both in the fluorinated alcohol hexafluoro-2-propanol (HFIP) and in sodium dodecyl sulfate (SDS) micelles. In both solvents, residues 68-78 take on an amphipathic helical structure, in agreement with predictions made by comparison to homologous saposin family proteins. In HFIP, the five N-terminal residues of the peptide are largely unstructured, while in SDS micelles, these residues take on a well-defined compact conformation. Differences in helical residue side chain positioning between the two solvents were also found, with better agreement between the structures for the hydrophobic face than the hydrophilic face. A paramagnetic probe was used to investigate the position of the peptide within the SDS micelles and indicated that the peptide is located at the water interface with the hydrophobic face of the helix oriented inward, the hydrophilic face of the helix oriented outward, and the N-terminal residues even farther from the micelle center than those on the hydrophilic face of the alpha-helix. Interactions of basic residues of SP-B with anionic lipid headgroups are known to have an impact on function, and these studies demonstrate structural ramifications of such interactions via the differences observed between the peptide structures determined in HFIP and SDS. | ||
| - | |||
| - | ==Disease== | ||
| - | Known disease associated with this structure: Surfactant metabolism dysfunction, pulmonary, 1 OMIM:[[http://www.ncbi.nlm.nih.gov/entrez/dispomim.cgi?id=178640 178640]] | ||
==About this Structure== | ==About this Structure== | ||
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[[Category: surfactant]] | [[Category: surfactant]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun Mar 30 23:27:40 2008'' |
Revision as of 20:27, 30 March 2008
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| Related: | 1RG3
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
SP-B C-terminal peptide in organic solvent (HFIP)
Overview
Although the membrane-associated surfactant protein B (SP-B) is an essential component of lung surfactant, which is itself essential for life, the molecular basis for its activity is not understood. SP-B's biophysical functions can be partially mimicked by subfragments of the protein, including the C-terminus. We have used NMR to determine the structure of a C-terminal fragment of human SP-B that includes residues 63-78. Structure determination was performed both in the fluorinated alcohol hexafluoro-2-propanol (HFIP) and in sodium dodecyl sulfate (SDS) micelles. In both solvents, residues 68-78 take on an amphipathic helical structure, in agreement with predictions made by comparison to homologous saposin family proteins. In HFIP, the five N-terminal residues of the peptide are largely unstructured, while in SDS micelles, these residues take on a well-defined compact conformation. Differences in helical residue side chain positioning between the two solvents were also found, with better agreement between the structures for the hydrophobic face than the hydrophilic face. A paramagnetic probe was used to investigate the position of the peptide within the SDS micelles and indicated that the peptide is located at the water interface with the hydrophobic face of the helix oriented inward, the hydrophilic face of the helix oriented outward, and the N-terminal residues even farther from the micelle center than those on the hydrophilic face of the alpha-helix. Interactions of basic residues of SP-B with anionic lipid headgroups are known to have an impact on function, and these studies demonstrate structural ramifications of such interactions via the differences observed between the peptide structures determined in HFIP and SDS.
About this Structure
1RG4 is a Single protein structure of sequence from [1]. Full crystallographic information is available from OCA.
Reference
NMR structures of the C-terminal segment of surfactant protein B in detergent micelles and hexafluoro-2-propanol., Booth V, Waring AJ, Walther FJ, Keough KM, Biochemistry. 2004 Dec 7;43(48):15187-94. PMID:15568810
Page seeded by OCA on Sun Mar 30 23:27:40 2008
Categories: Single protein | Booth, V. | Keough, K M. | Walther, F J. | Waring, A J. | Lung | Sp-b | Surfactant
