Two-dimensional 1H NMR experiments show that the 23-residue magainin antibiotic peptide is an α-helix in dodecylphosphocholine micelles, sodium dodecylsulfate micelles, and trifluoroethanol/water solution.

Autor: Gesell, Jennifer, Zasloff, Michael, Opella, Stanley
Zdroj: Journal of Biomolecular NMR; Feb1997, Vol. 9 Issue 2, p127-135, 9p
Abstrakt: Magainin2 is a 23-residue antibiotic peptide that disrupts the ionic gradient across certain cellmembranes. Two-dimensional 1H NMR spectroscopy was used to investigate the structure ofthe peptide in three of the membrane environments most commonly employed in biophysicalstudies. Sequence-specific resonance assignments were determined for the peptide inperdeuterated dodecylphosphocholine (DPC) and sodium dodecylsulfate micelles andconfirmed for the peptide in 2,2,2-trifluoroethanol solution. The secondary structure is shownto be helical in all of the solvent systems. The NMR data were used as a set of restraints fora simulated annealing protocol that generated a family of three-dimensional structures of thepeptide in DPC micelles, which superimposed best between residues 4 and 20. For theseresidues, the mean pairwise rms difference for the backbone atoms is 0.47 ± 0.10Å from the average structure. The calculated peptide structures appear to be curved,with the bend centered at residues Phe12 and Gly13. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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