title: Estimation of 3JHN-Halpha and 3JHalpha-Hbeta coupling constants from heteronuclear TOCSY spectra.
abstract: (3)J proton-proton coupling constants bear information on the intervening dihedral angles. Methods have been developed to derive this information from NMR spectra of proteins. Using series expansion of the time dependent density matrix, and exploiting the simple topology of amino acid spin-systems, formulae for estimation of (3)J(HN-Halpha) and (3)J(Halpha-Hbeta) from HSQC-TOCSY spectra are derived. The results obtained on a protein entailing both alpha-helix and beta-sheet secondary structure elements agree very well with J-coupling constants computed from the X-ray structure. The method compares well with existing methods and requires only 2D spectra which would be typically otherwise recorded for structural studies.
authors: Dipartimento di Scienze e Tecnologie Biomediche, Università di Udine, Piazzale Kolbe 4, Udine, Italy.
authors: Katiuscia
authors: K
authors: Pagano
authors: Federico
authors: F
authors: Fogolari
authors: Alessandra
authors: A
authors: Corazza
authors: Paolo
authors: P
authors: Viglino
authors: Gennaro
authors: G
authors: Esposito
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D003198:Computer Simulation; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008958:Models, Molecular; D017433:Protein Structure, Secondary; D011506:Proteins / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D011506:Proteins