title: Structure and topology of a peptide segment of the 6th transmembrane domain of the Saccharomyces cerevisae alpha-factor receptor in phospholipid bilayers.
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.
authors.affiliation: Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA 19104, USA.
authors.forename: K G
authors.initials: KG
authors.lastname: Valentine
authors.forename: S F
authors.initials: SF
authors.lastname: Liu
authors.forename: F M
authors.initials: FM
authors.lastname: Marassi
authors.forename: G
authors.initials: G
authors.lastname: Veglia
authors.forename: S J
authors.initials: SJ
authors.lastname: Opella
authors.forename: F X
authors.initials: FX
authors.lastname: Ding
authors.forename: S H
authors.initials: SH
authors.lastname: Wang
authors.forename: B
authors.initials: B
authors.lastname: Arshava
authors.forename: J M
authors.initials: JM
authors.lastname: Becker
authors.forename: F
authors.initials: F
authors.lastname: Naider
mesh_terms: D000595:Amino Acid Sequence; D001704:Biopolymers / Q000737:chemistry / Q000235:genetics; D008051:Lipid Bilayers; D009682:Magnetic Resonance Spectroscopy; D000072235:Mating Factor; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009587:Nitrogen Isotopes; D010455:Peptides / Q000737:chemistry; D010743:Phospholipids; D017434:Protein Structure, Tertiary; D051964:Receptors, Mating Factor; D018000:Receptors, Peptide / Q000737:chemistry* / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000235:genetics; D017550:Spectroscopy, Fourier Transform Infrared; D014157:Transcription Factors
chemical_list: D001704:Biopolymers; D008051:Lipid Bilayers; D009587:Nitrogen Isotopes; D010455:Peptides; D010743:Phospholipids; D051964:Receptors, Mating Factor; D018000:Receptors, Peptide; D014157:Transcription Factors; D000072235:Mating Factor