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1erf
From Proteopedia
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[[Image:1erf.gif|left|200px]] | [[Image:1erf.gif|left|200px]] | ||
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'''CONFORMATIONAL MAPPING OF THE N-TERMINAL FUSION PEPTIDE OF HIV-1 GP41 USING 13C-ENHANCED FOURIER TRANSFORM INFRARED SPECTROSCOPY (FTIR)''' | '''CONFORMATIONAL MAPPING OF THE N-TERMINAL FUSION PEPTIDE OF HIV-1 GP41 USING 13C-ENHANCED FOURIER TRANSFORM INFRARED SPECTROSCOPY (FTIR)''' | ||
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==About this Structure== | ==About this Structure== | ||
| - | 1ERF is a [[Single protein]] structure | + | 1ERF is a [[Single protein]] structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1ERF OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Sherman, M A.]] | [[Category: Sherman, M A.]] | ||
[[Category: Waring, A J.]] | [[Category: Waring, A J.]] | ||
| - | [[Category: | + | [[Category: Gp41]] |
| - | [[Category: | + | [[Category: Viral fusion peptide]] |
| - | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 15:26:02 2008'' | |
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| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | |
Revision as of 12:26, 2 May 2008
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. 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 Page seeded by OCA on Fri May 2 15:26:02 2008
