Determination of three-bond scalar coupling between [formula omitted] and [formula omitted] in proteins using an iHN(CA),CO(α/β- J-COHA) experiment

Abstract

Triple-resonance NMR experiments for measuring three-bond scalar coupling constant between 13 C ′(i−1) and 1 H α (i) spins, defining the dihedral angle φ, are presented. The novel experiments enable the measurement of 3J C ′ H α from simple two (or three)-dimensional 13 C ′ , ( 15 N/ 13 C α ) , 1 H N correlation spectra with minimal resonance overlap, thanks to solely intraresidual coherence transfer pathway and spin-state-selection. The 3J C ′ H α values measured in human ubiquitin using the proposed intraresidual iHN(CA),CO(α/β- J-COHA) TROSY method were compared with those determined previously utilizing the HCAN[C ′] experiment.