title: The DQ-HN[CACB] and DQ-HN(CO)[CACB] sequences with evolution of double quantum Calpha-Cbeta coherences.
abstract: The new variant of known HNCACB and HN(CO)CACB techniques is proposed that employs excitation and evolution of double quantum Calpha-Cbeta coherences. The most important features of the new method are: increased signal dispersion, lack of splittings due to 1J(Calpha-Cbeta) spin-spin couplings, and absence of accidental cancellations of positive and negative signals. The acquisition of both DQ-HN[CACB] and DQ-HN(CO)[CACB] techniques enables sequential assignment of protein backbone, using only Calpha-Cbeta DQ-frequencies. The determination of all Calpha and Cbeta chemical shifts requires, however, a comparison with HN(CO)CA or HNCA spectra. Examples of applications of the DQ-HN[CACB] and DQ-HN(CO)[CACB] experiments are presented, employing the 2D Reduced Dimensionality approach for 13C, 15N-labeled ubiquitin, and the 3D acquisition for 13C, 15N-double labeled Ca2+ -binding bovine S100A1 protein in the apo state (21 kDa) with overall correlation time of 8.1 ns.
authors.affiliation: Department of Chemistry, Warsaw University, ul. Pasteura 1, 02-093 Warszawa, Poland. kozmin@chem.uw.edu.pl
authors.forename: Wiktor
authors.initials: W
authors.lastname: Koźmiński
authors.forename: Igor
authors.initials: I
authors.lastname: Zhukov
mesh_terms: D000818:Animals; D002135:Calcium-Binding Proteins / Q000737:chemistry*; D002247:Carbon Isotopes; D002417:Cattle; D006859:Hydrogen; D009587:Nitrogen Isotopes; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D009418:S100 Proteins; D025801:Ubiquitin / Q000737:chemistry*
chemical_list: D002135:Calcium-Binding Proteins; D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D009418:S100 Proteins; C110294:S100A1 protein; D025801:Ubiquitin; D006859:Hydrogen