Improved detection of long-range residual dipolar couplings in weakly aligned samples by Lee-Goldburg decoupling of homonuclear dipolar truncation

J Biomol NMR. 2004 Dec;30(4):443-50. doi: 10.1007/s10858-004-5318-0.

Abstract

Homonuclear (1)H residual dipolar couplings (RDCs) truncate the evolution of transverse (1)H magnetization of weakly aligned molecules in high-resolution NMR experiments. This leads to losses in sensitivity or resolution in experiments that require extended (1)H evolution times. Lee-Goldburg decoupling schemes have been shown to remove the effects of homonuclear dipolar couplings, while preserving chemical shift evolution in a number of solid-state NMR applications. Here, it is shown that the Lee-Goldburg sequence can be effectively incorporated into INEPT- or HMQC-type transfer schemes in liquid state weak alignment experiments in order to increase the efficiency of the magnetization transfer. The method is applied to the sensitive detection of (1)H(N)-(13)C long-range RDCs in a three-dimensional HCN experiment. As compared to a conventional HCN experiment, an average sensitivity increase by a factor of 2.4 is obtained for a sample of weakly aligned protein G. This makes it possible to detect 170 long-range (1)H(N)-(13)C RDCs for distances up to 4.9 angstroms.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carbon Isotopes
  • Nerve Tissue Proteins / chemistry
  • Nuclear Magnetic Resonance, Biomolecular / methods*
  • Protons
  • Sensitivity and Specificity

Substances

  • Carbon Isotopes
  • G-substrate
  • Nerve Tissue Proteins
  • Protons