Three-Dimensional Solid-State NMR Spectroscopy Is Essential for Resolution of Resonances from In-Plane Residues in Uniformly 15N-Labeled Helical Membrane Proteins in Oriented Lipid Bilayers
✍ Scribed by Francesca M Marassi; Che Ma; Jennifer J Gesell; Stanley J Opella
- Publisher
- Elsevier Science
- Year
- 2000
- Tongue
- English
- Weight
- 188 KB
- Volume
- 144
- Category
- Article
- ISSN
- 1090-7807
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✦ Synopsis
Uniformly 15 N-labeled samples of membrane proteins with helices aligned parallel to the membrane surface give two-dimensional PISEMA spectra that are highly overlapped due to limited dispersions of 1 H-15 N dipolar coupling and 15 N chemical shift frequencies. However, resolution is greatly improved in threedimensional 1 H chemical shift/ 1 H-15 N dipolar coupling/ 15 N chemical shift correlation spectra. The 23-residue antibiotic peptide magainin and a 54-residue polypeptide corresponding to the cytoplasmic domain of the HIV-1 accessory protein Vpu are used as examples. Both polypeptides consist almost entirely of ␣-helices, with their axes aligned parallel to the membrane surface. The measurement of three orientationally dependent frequencies for Val17 of magainin enabled the three-dimensional orientation of this helical peptide to be determined in the lipid bilayer.