Efficient band-selective homonuclear CO-CA cross-polarization in protonated proteins

J Biomol NMR. 2013 Aug;56(4):303-11. doi: 10.1007/s10858-013-9767-1. Epub 2013 Aug 8.

Abstract

Previously introduced for highly deuterated proteins, band-selective magnetization transfer between CO and CA spins by dipolar-based homonuclear cross polarization is applied here to a protonated protein. Robust and efficient recoupling is achieved when the sum of effective radio-frequency fields on CO and CA resonances equals two times the spinning rate, yielding up to 33% of magnetization transfer efficiency in protonated ubiquitin. The approach is designed for moderate magic-angle spinning rates and high external magnetic fields when the isotropic chemical shift difference of CO and CA considerably exceeds the spinning rate. This method has been implemented in NiCOi-1CAi-1 and CAi(Ni)COi-1CAi-1 two-dimensional interresidual correlation experiments for fast and efficient resonance assignment of ubiquitin by solid-state NMR spectroscopy.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Nuclear Magnetic Resonance, Biomolecular*
  • Proteins / chemistry*
  • Protons*
  • Radio Waves
  • Signal Processing, Computer-Assisted
  • Ubiquitin / chemistry

Substances

  • Proteins
  • Protons
  • Ubiquitin