PAIN with and without PAR: variants for third-spin assisted heteronuclear polarization transfer.
J Biomol NMR
; 56(4): 365-77, 2013 Aug.
Article
em En
| MEDLINE
| ID: mdl-23807391
ABSTRACT
In this article, we describe third-spin assisted heteronuclear recoupling experiments, which play an increasingly important role in measuring long-range heteronuclear couplings, in particular (15)N-(13)C, in proteins. In the proton-assisted insensitive nuclei cross polarization (PAIN-CP) experiment (de Paëpe et al. in J Chem Phys 134095101, 2011), heteronuclear polarization transfer is always accompanied by homonuclear transfer of the proton-assisted recoupling (PAR) type. We present a phase-alternating experiment that promotes heteronuclear (e.g. (15)N â (13)C) polarization transfer while simultaneously minimizing homonuclear (e.g.(13)C â (13)C) transfer (PAIN without PAR). This minimization of homonuclear polarization transfer is based on the principle of the resonant second-order transfer (RESORT) recoupling scheme where the passive proton spins are irradiated by a phase-alternating sequence and the modulation frequency is matched to an integer multiple of the spinning frequency. The similarities and differences between the PAIN-CP and this het-RESORT experiment are discussed here.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Prótons
/
Marcadores de Spin
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Ressonância Magnética Nuclear Biomolecular
Tipo de estudo:
Prognostic_studies
Idioma:
En
Ano de publicação:
2013
Tipo de documento:
Article