1spf
From Proteopedia
(New page: 200px<br /><applet load="1spf" size="450" color="white" frame="true" align="right" spinBox="true" caption="1spf" /> '''THE NMR STRUCTURE OF THE PULMONARY SURFACTAN...) |
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'''THE NMR STRUCTURE OF THE PULMONARY SURFACTANT-ASSOCIATED POLYPEPTIDE SP-C IN AN APOLAR SOLVENT CONTAINS A VALYL-RICH ALPHA-HELIX'''<br /> | '''THE NMR STRUCTURE OF THE PULMONARY SURFACTANT-ASSOCIATED POLYPEPTIDE SP-C IN AN APOLAR SOLVENT CONTAINS A VALYL-RICH ALPHA-HELIX'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The nuclear magnetic resonance (NMR) structure of the pulmonary | + | The nuclear magnetic resonance (NMR) structure of the pulmonary surfactant-associated lipoplypeptide C (SP-C) was determined in a mixed solvent of C2H3Cl/C2H3OH/ 1 M HCl 32:64:5 (v/v). Sequence-specific 1H NMR assignments and the collection of conformational constraints were achieved with two-dimensional 1H NMR, and the structure was calculated with the distance geometry program DIANA. The root mean square deviations for the well-defined polypeptide segment of residues 9-34 calculated for the 20 best energy-minimized DIANA conformers relative to their mean are 0.5 and 1.3 A for the polypeptide backbone atoms N, C alpha, and C', and for all heavy atoms, respectively. The 35-residue polypeptide chain of SP-C forms an alpha-helix between positions 9 and 34, which includes two segments of seven and four consecutive valyls that are separated by a single leucyl residue. The N-terminal hexapeptide segment, which includes two palmitoylcysteinyls, is flexibly disordered. The length of the alpha-helix is about 37 A, and the helical segment of residues 13-28, which contains exclusively aliphatic residues with branched side chains, is 23-A long and about 10 A in diameter. The alpha-helix is outstandingly regular, with virtually identical chi 1 angles for all valyl residues. The observation of a helical structure of SP-C was rather unexpected, considering that Val is generally underrepresented in alpha-helices, and it provides intriguing novel insights into the structural basis of SP-C functions as well as into general structural aspects of protein-lipid interactions in biological membranes. |
==About this Structure== | ==About this Structure== | ||
| - | 1SPF is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Sus_scrofa Sus scrofa]. Full crystallographic information is available from [http:// | + | 1SPF is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Sus_scrofa Sus scrofa]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1SPF OCA]. |
==Reference== | ==Reference== | ||
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[[Category: lipoprotein(surface film)]] | [[Category: lipoprotein(surface film)]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:03:53 2008'' |
Revision as of 13:03, 21 February 2008
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THE NMR STRUCTURE OF THE PULMONARY SURFACTANT-ASSOCIATED POLYPEPTIDE SP-C IN AN APOLAR SOLVENT CONTAINS A VALYL-RICH ALPHA-HELIX
Overview
The nuclear magnetic resonance (NMR) structure of the pulmonary surfactant-associated lipoplypeptide C (SP-C) was determined in a mixed solvent of C2H3Cl/C2H3OH/ 1 M HCl 32:64:5 (v/v). Sequence-specific 1H NMR assignments and the collection of conformational constraints were achieved with two-dimensional 1H NMR, and the structure was calculated with the distance geometry program DIANA. The root mean square deviations for the well-defined polypeptide segment of residues 9-34 calculated for the 20 best energy-minimized DIANA conformers relative to their mean are 0.5 and 1.3 A for the polypeptide backbone atoms N, C alpha, and C', and for all heavy atoms, respectively. The 35-residue polypeptide chain of SP-C forms an alpha-helix between positions 9 and 34, which includes two segments of seven and four consecutive valyls that are separated by a single leucyl residue. The N-terminal hexapeptide segment, which includes two palmitoylcysteinyls, is flexibly disordered. The length of the alpha-helix is about 37 A, and the helical segment of residues 13-28, which contains exclusively aliphatic residues with branched side chains, is 23-A long and about 10 A in diameter. The alpha-helix is outstandingly regular, with virtually identical chi 1 angles for all valyl residues. The observation of a helical structure of SP-C was rather unexpected, considering that Val is generally underrepresented in alpha-helices, and it provides intriguing novel insights into the structural basis of SP-C functions as well as into general structural aspects of protein-lipid interactions in biological membranes.
About this Structure
1SPF is a Single protein structure of sequence from Sus scrofa. Full crystallographic information is available from OCA.
Reference
The NMR structure of the pulmonary surfactant-associated polypeptide SP-C in an apolar solvent contains a valyl-rich alpha-helix., Johansson J, Szyperski T, Curstedt T, Wuthrich K, Biochemistry. 1994 May 17;33(19):6015-23. PMID:8180229
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