BEST and SOFAST experiments for resonance assignment of histidine and tyrosine side chains in 13C/15N labeled proteins

J Biomol NMR. 2018 Dec;72(3-4):115-124. doi: 10.1007/s10858-018-0216-z. Epub 2018 Nov 21.


Aromatic amino-acid side chains are essential components for the structure and function of proteins. We present herein a set of NMR experiments for time-efficient resonance assignment of histidine and tyrosine side chains in uniformly 13C/15N-labeled proteins. The use of band-selective 13C pulses allows to deal with linear chains of coupled spins, thus avoiding signal loss that occurs in branched spin systems during coherence transfer. Furthermore, our pulse schemes make use of longitudinal 1H relaxation enhancement, Ernst-angle excitation, and simultaneous detection of 1H and 13C steady-state polarization to achieve significant signal enhancements.

Keywords: Aromatics; BEST; Histidine tautomerization; Longitudinal relaxation enhancement; NMR assignment.

MeSH terms

  • Algorithms
  • Carbon Isotopes
  • Histidine*
  • Nitrogen Isotopes
  • Nuclear Magnetic Resonance, Biomolecular / methods*
  • Protein Conformation
  • Proteins / chemistry*
  • Tyrosine*


  • Carbon Isotopes
  • Nitrogen Isotopes
  • Nitrogen-15
  • Proteins
  • Tyrosine
  • Histidine
  • Carbon-13