Abstract
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 three-dimensional (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 alpha-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.
- accessory
- and
- animals,antimicrobial
- bilayers,magainins,magnetic
- cationic
- immunodeficiency
- isotopes,peptides,protein
- peptides,hiv-1,human
- proteins
- proteins,lipid
- proteins,nitrogen
- proteins,xenopus
- regulatory
- resonance
- spectroscopy,membrane
- structure,secondary,viral
- virus
Users
Please
log in to take part in the discussion (add own reviews or comments).