Structure and Topology of a Peptide Segment of the 6th Transmembrane Domain of the Saccharomyces cerevisiae alpha-Factor Receptor in Phospholipid BilayersValentine, K.G., Liu, S.-F., Marassi, F.M., Veglia, G., Opella, S.J., Ding, F.-X., Wang, S.-H., Arshava, B., Becker, J.M., Naider, F.
(2001) Biopolymers 59: 243-256
- PubMed: 11473349
- DOI: https://doi.org/10.1002/1097-0282(20011005)59:4<243::AID-BIP1021>3.0.CO;2-H
- Primary Citation of Related Structures:
- PubMed Abstract:
A detailed analysis of the structure of an 18-residue peptide AQSLLVPSIIFILAYSLK [M6(252-269, C252A)] in 1,2-dimyristoyl-sn-glycero-phosphocholine bilayers was carried out using solid state NMR and attenuated total reflection Fourier transform infrared spectroscopy. The peptide corresponds to a portion of the 6th transmembrane domain of the alpha-factor receptor of Saccharomyces cerevisiae. Ten homologs of M6(252-269, C252A) were synthesized in which individual residues were labeled with (15)N. One- and two-dimensional solid state NMR experiments were used to determine the chemical shifts and (1)H-(15)N dipolar coupling constants for the (15)N-labeled peptides in oriented dimyristoylphosphatidylcholine bilayers on stacked glass plates. These parameters were used to calculate the structure and orientation of M6(252-269, C252A) in the bilayers. The results indicate that the carboxyl terminal residues (9-14) are alpha-helical and oriented with an angle of about 8 degrees with respect to the bilayer normal. Independently, an attenuated total reflection Fourier transform infrared spectroscopy analysis on M6(252-269, C252A) in a 1,2-dimyristoyl-sn-glycero-phosphocholine bilayer concluded that the helix tilt angle was about 12.5 degrees. The results on the structure of M6(252-269, C252A) in bilayers are in good agreement with the structure determined in trifluoroethanol/water solutions (B. Arshava et al. Biopolymers, 1998, Vol. 46, pp. 343-357). The present study shows that solid state NMR spectroscopy can provide high resolution information on the structure of transmembrane domains of a G protein-coupled receptor.
Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA 19104, USA.