Solid-state NMR spectroscopy of oriented membrane polypeptides at 100 K with signal enhancement by dynamic nuclear polarization

J Am Chem Soc. 2010 May 5;132(17):5940-1. doi: 10.1021/ja1007646.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Membrane Proteins / chemistry*
  • Molecular Sequence Data
  • Nuclear Magnetic Resonance, Biomolecular
  • Peptides / chemistry*

Substances

  • Membrane Proteins
  • Peptides