title: Improved detection of long-range residual dipolar couplings in weakly aligned samples by Lee-Goldburg decoupling of homonuclear dipolar truncation.
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.
authors.affiliation: Division of Structural Biology, Biozentrum der Universität Basel, Klingelbergstrasse 70, CH-4056, Basel, Switzerland.
authors.forename: Pernille
authors.initials: P
authors.lastname: Jensen
authors.forename: Hans-Jürgen
authors.initials: HJ
authors.lastname: Sass
authors.forename: Stephan
authors.initials: S
authors.lastname: Grzesiek
mesh_terms: D002247:Carbon Isotopes; D009419:Nerve Tissue Proteins / Q000737:chemistry; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D011522:Protons; D012680:Sensitivity and Specificity
chemical_list: D002247:Carbon Isotopes; C029152:G-substrate; D009419:Nerve Tissue Proteins; D011522:Protons