1erf
From Proteopedia
(New page: 200px<br /> <applet load="1erf" size="450" color="white" frame="true" align="right" spinBox="true" caption="1erf" /> '''CONFORMATIONAL MAPPING OF THE N-TERMINAL FU...) |
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'''CONFORMATIONAL MAPPING OF THE N-TERMINAL FUSION PEPTIDE OF HIV-1 GP41 USING 13C-ENHANCED FOURIER TRANSFORM INFRARED SPECTROSCOPY (FTIR)'''<br /> | '''CONFORMATIONAL MAPPING OF THE N-TERMINAL FUSION PEPTIDE OF HIV-1 GP41 USING 13C-ENHANCED FOURIER TRANSFORM INFRARED SPECTROSCOPY (FTIR)'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The N-terminal domain of HIV-1 glycoprotein 41000 (FP; residues 1--23; | + | The N-terminal domain of HIV-1 glycoprotein 41000 (FP; residues 1--23; AVGIGALFLGFLGAAGSTMGARSCONH(2)) participates in fusion processes underlying virus--cell infection. Here, we use physical techniques to study the secondary conformation of synthetic FP in aqueous, structure-promoting, lipid and biomembrane environments. Circular dichroism and conventional, (12)C-Fourier transform infrared (FTIR) spectroscopy indicated the following alpha-helical levels for FP in 1-palmitoyl-2-oleoylphosphatidylglycerol (POPG) liposomes-hexafluoroisopropanol (HFIP)>trifluoroethanol (TFE)>phosphate-buffered saline (PBS). (12)C-FTIR spectra also showed disordered FP structures in these environments, along with substantial beta-structures for FP in TFE or PBS. In further experiments designed to map secondary conformations to specific residues, isotope-enhanced FTIR spectroscopy was performed using a suite of FP peptides labeled with (13)C-carbonyl at multiple sites. Combining these (13)C-enhanced FTIR results with molecular simulations indicated the following model for FP in HFIP: alpha-helix (residues 3-16) and random and beta-structures (residues 1-2 and residues 17-23). Additional (13)C-FTIR analysis indicated a similar conformation for FP in POPG at low peptide loading, except that the alpha-helix extends over residues 1-16. At low peptide loading in either human erythrocyte ghosts or lipid extracts from ghosts, (13)C-FTIR spectroscopy showed alpha-helical conformations for the central core of FP (residues 5-15); on the other hand, at high peptide loading in ghosts or lipid extracts, the central core of FP assumed an antiparallel beta-structure. FP at low loading in ghosts probably inserts deeply as an alpha-helix into the hydrophobic membrane bilayer, while at higher loading FP primarily associates with ghosts as an aqueous-accessible, beta-sheet. In future studies, (13)C-FTIR spectroscopy may yield residue-specific conformations for other membrane-bound proteins or peptides, which have been difficult to analyze with more standard methodologies. |
==About this Structure== | ==About this Structure== | ||
| - | 1ERF is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/ ] with NH2 as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http:// | + | 1ERF is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/ ] with <scene name='pdbligand=NH2:'>NH2</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1ERF OCA]. |
==Reference== | ==Reference== | ||
Conformational mapping of the N-terminal peptide of HIV-1 gp41 in membrane environments using (13)C-enhanced Fourier transform infrared spectroscopy., Gordon LM, Mobley PW, Pilpa R, Sherman MA, Waring AJ, Biochim Biophys Acta. 2002 Feb 15;1559(2):96-120. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=11853678 11853678] | Conformational mapping of the N-terminal peptide of HIV-1 gp41 in membrane environments using (13)C-enhanced Fourier transform infrared spectroscopy., Gordon LM, Mobley PW, Pilpa R, Sherman MA, Waring AJ, Biochim Biophys Acta. 2002 Feb 15;1559(2):96-120. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=11853678 11853678] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Gordon, L | + | [[Category: Gordon, L M.]] |
| - | [[Category: Mobley, P | + | [[Category: Mobley, P W.]] |
[[Category: Pilpa, R.]] | [[Category: Pilpa, R.]] | ||
| - | [[Category: Sherman, M | + | [[Category: Sherman, M A.]] |
| - | [[Category: Waring, A | + | [[Category: Waring, A J.]] |
[[Category: NH2]] | [[Category: NH2]] | ||
[[Category: gp41]] | [[Category: gp41]] | ||
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[[Category: viral fusion peptide]] | [[Category: viral fusion peptide]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:30:41 2008'' |
Revision as of 10:30, 21 February 2008
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CONFORMATIONAL MAPPING OF THE N-TERMINAL FUSION PEPTIDE OF HIV-1 GP41 USING 13C-ENHANCED FOURIER TRANSFORM INFRARED SPECTROSCOPY (FTIR)
Overview
The N-terminal domain of HIV-1 glycoprotein 41000 (FP; residues 1--23; AVGIGALFLGFLGAAGSTMGARSCONH(2)) participates in fusion processes underlying virus--cell infection. Here, we use physical techniques to study the secondary conformation of synthetic FP in aqueous, structure-promoting, lipid and biomembrane environments. Circular dichroism and conventional, (12)C-Fourier transform infrared (FTIR) spectroscopy indicated the following alpha-helical levels for FP in 1-palmitoyl-2-oleoylphosphatidylglycerol (POPG) liposomes-hexafluoroisopropanol (HFIP)>trifluoroethanol (TFE)>phosphate-buffered saline (PBS). (12)C-FTIR spectra also showed disordered FP structures in these environments, along with substantial beta-structures for FP in TFE or PBS. In further experiments designed to map secondary conformations to specific residues, isotope-enhanced FTIR spectroscopy was performed using a suite of FP peptides labeled with (13)C-carbonyl at multiple sites. Combining these (13)C-enhanced FTIR results with molecular simulations indicated the following model for FP in HFIP: alpha-helix (residues 3-16) and random and beta-structures (residues 1-2 and residues 17-23). Additional (13)C-FTIR analysis indicated a similar conformation for FP in POPG at low peptide loading, except that the alpha-helix extends over residues 1-16. At low peptide loading in either human erythrocyte ghosts or lipid extracts from ghosts, (13)C-FTIR spectroscopy showed alpha-helical conformations for the central core of FP (residues 5-15); on the other hand, at high peptide loading in ghosts or lipid extracts, the central core of FP assumed an antiparallel beta-structure. FP at low loading in ghosts probably inserts deeply as an alpha-helix into the hydrophobic membrane bilayer, while at higher loading FP primarily associates with ghosts as an aqueous-accessible, beta-sheet. In future studies, (13)C-FTIR spectroscopy may yield residue-specific conformations for other membrane-bound proteins or peptides, which have been difficult to analyze with more standard methodologies.
About this Structure
1ERF is a Single protein structure of sequence from [1] with as ligand. Full crystallographic information is available from OCA.
Reference
Conformational mapping of the N-terminal peptide of HIV-1 gp41 in membrane environments using (13)C-enhanced Fourier transform infrared spectroscopy., Gordon LM, Mobley PW, Pilpa R, Sherman MA, Waring AJ, Biochim Biophys Acta. 2002 Feb 15;1559(2):96-120. PMID:11853678
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