Gradient reconstitution of membrane proteins for solid-state NMR studies

J Biomol NMR. 2017 Oct;69(2):81-91. doi: 10.1007/s10858-017-0135-4. Epub 2017 Sep 12.

Abstract

We here adapted the GRecon method used in electron microscopy studies for membrane protein reconstitution to the needs of solid-state NMR sample preparation. We followed in detail the reconstitution of the ABC transporter BmrA by dialysis as a reference, and established optimal reconstitution conditions using the combined sucrose/cyclodextrin/lipid gradient characterizing GRecon. We established conditions under which quantitative reconstitution of active protein at low lipid-to-protein ratios can be obtained, and also how to upscale these conditions in order to produce adequate amounts for NMR. NMR spectra recorded on a sample produced by GRecon showed a highly similar fingerprint as those recorded previously on samples reconstituted by dialysis. GRecon sample preparation presents a gain in time of nearly an order of magnitude for reconstitution, and shall represent a valuable alternative in solid-state NMR membrane protein sample preparation.

Keywords: ABC-transporter; BmrA; Membrane proteins reconstitution; Solid-state NMR.

MeSH terms

  • Bacterial Proteins / chemistry
  • Lipids / chemistry
  • Mass Spectrometry
  • Membrane Proteins / chemistry*
  • Membrane Transport Proteins / chemistry
  • Nuclear Magnetic Resonance, Biomolecular* / methods

Substances

  • Bacterial Proteins
  • Lipids
  • Membrane Proteins
  • Membrane Transport Proteins
  • Bmr protein, Bacillus subtilis