title: Solid-state NMR spectroscopy of oriented membrane polypeptides at 100 K with signal enhancement by dynamic nuclear polarization.
abstract: Oriented membrane samples encompassing the biradical bTbK and a transmembrane peptide carrying a single (15)N labeled residue have been prepared on polymer sheets with sample geometries that fit into a 3.2 mm MAS rotor. The proton-decoupled (15)N cross-polarization spectra of the peptide were characterized by a single line at fast magic angle spinning speeds of approximately 8 kHz. Irradiating these samples with mu-waves resulted in Dynamic Nuclear Polarization and a concomitant 18-fold signal enhancement which considerably shortened the NMR acquisition times. Furthermore, the sideband patterns of magic angle oriented sample spinning (MAOSS) solid-state NMR spectra at slow spinning speeds (approximately 1 kHz) are indicative that the lipids and peptides form well-oriented bilayers at 100 K despite the narrow inner diameter of the rotor (2.2 mm) and the presence of considerable amounts of biradicals. The DNP signal enhancement opens up enhanced possibilities for multidimensional solid-state NMR investigation of oriented membrane polypeptides.
authors.affiliation: Insitut de Chimie, Université de Strasbourg-CNRS UMR7177, 4 rue Blaise Pascal, 67070 Strasbourg, France.
authors.forename: Evgeniy
authors.initials: E
authors.lastname: Salnikov
authors.forename: Melanie
authors.initials: M
authors.lastname: Rosay
authors.forename: Shane
authors.initials: S
authors.lastname: Pawsey
authors.forename: Olivier
authors.initials: O
authors.lastname: Ouari
authors.forename: Paul
authors.initials: P
authors.lastname: Tordo
authors.forename: Burkhard
authors.initials: B
authors.lastname: Bechinger
mesh_terms: D000595:Amino Acid Sequence; D008565:Membrane Proteins / Q000737:chemistry*; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D010455:Peptides / Q000737:chemistry*
chemical_list: D008565:Membrane Proteins; D010455:Peptides