title: The new HMQC-based technique for the quantitative determination of heteronuclear coupling constants. Application for the measurement of 3J(H'(i),P(i+1)) in DNA oligomers.
abstract: A new general J-HMQC-based technique is presented, which allows an accurate determination of heteronuclear coupling constants. The most important feature of this new approach includes acquisition of the two data sets with and without the additional pi(S)-pulse at the end of coupling evolution period. This enables preservation and separation of the two orthogonal terms of coupling evolution, which are manifested by in- and antiphase cross-peaks, respectively. The coupling magnitudes are evaluated by the nonlinear least-squares fitting of the ratios of integrated signal volumes for both kinds of signals. The effectiveness of the new sequence is demonstrated by determination of the 3J(H3'(i),P(i+1)) couplings in DNA octamer duplex d(GCGTACGC)(2) sample. Additionally, the ability of the new method for the measurement at the natural abundance level of 13C nuclei is presented for the beta-cyclodextrin.
authors.affiliation: Department of Chemistry, Warsaw University, ul. Pasteura 1, 02-093 Warsaw, Poland. kozmin@chem.uw.edu.pl
authors.forename: Wiktor
authors.initials: W
authors.lastname: Koźmiński
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Bednarek
authors.forename: Wojciech
authors.initials: W
authors.lastname: Bocian
authors.forename: Jerzy
authors.initials: J
authors.lastname: Sitkowski
authors.forename: Lech
authors.initials: L
authors.lastname: Kozerski
mesh_terms: D002247:Carbon Isotopes / Q000737:chemistry*; D003505:Cyclodextrins / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008969:Molecular Sequence Data
chemical_list: D002247:Carbon Isotopes; D003505:Cyclodextrins; D004247:DNA