Off-resonance TROSY (R1 rho - R1) for quantitation of fast exchange processes in large proteins

J Am Chem Soc. 2003 Oct 8;125(40):12064-5. doi: 10.1021/ja037101s.


Current solution NMR experiments for characterizing conformational exchange processes in large proteins are limited to exchange rates ca. 500-3000 s-1. A TROSY-based constant relaxation time (R1rho - R1) experiment is designed to extend this capability to measure motion with rates up to 105 s-1 in large macromolecules. The experiment combines off-resonance spin-lock rf fields, which provide access to the faster time-scale dynamics, with TROSY coherence selection, which extends the molecular-weight range available for study. When implemented on the 53-kDa dimeric enzyme triosephosphate isomerase, the experiment yielded substantial gains in signal-to-noise (up to 60%) over current experiments at modest static magnetic fields (14.1 T). The TROSY (R1rho - R1) experiment should therefore be of general utility for investigation of fast conformational exchange events in large proteins.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Kinetics
  • Nuclear Magnetic Resonance, Biomolecular / methods*
  • Protein Conformation
  • Proteins / chemistry*


  • Proteins