title: Heteronuclear isotropic mixing separated local field NMR spectroscopy.
abstract: This paper presents a theoretical, numerical, and experimental study of a new class of separated local field (SLF) techniques. These techniques are based on the heteronuclear isotropic mixing leading to spin exchange via the local field (HIMSELF). It is shown that highly efficient and robust SLF experiments can be designed based on double channel windowless homonuclear decoupling sequences. Compared to rotating frame techniques based on Hartmann-Hahn cross polarization, the new approach is less susceptible to the frequency offset and chemical shift interaction and can be applied in the structural studies of macromolecules that are uniformly labeled with isotopes such as (13)C and (15)N. Furthermore, isotropic mixing sequences allow for transfer of any magnetization component of one nucleus to the corresponding component of its dipolar coupled partner. The performance of HIMSELF is studied by analysis of the average Hamiltonian and numerical simulation and is experimentally demonstrated on a single crystalline sample of a dipeptide and a liquid crystalline sample exhibiting motionally averaged dipolar couplings.
authors.affiliation: Biophysics Research Division, University of Michigan, Ann Arbor, MI 48109-1055, USA. sdvinskikh@mail.ru
authors.forename: Sergey V
authors.initials: SV
authors.lastname: Dvinskikh
authors.forename: Kazutoshi
authors.initials: K
authors.lastname: Yamamoto
authors.forename: Ayyalusamy
authors.initials: A
authors.lastname: Ramamoorthy
mesh_terms: D002247:Carbon Isotopes / Q000737:chemistry; D004574:Electromagnetic Fields; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008962:Models, Theoretical; D009587:Nitrogen Isotopes / Q000737:chemistry
chemical_list: D002247:Carbon Isotopes; D009587:Nitrogen Isotopes