3D HSQC-TOCSY-NOESY-HSQC NMR Experiment
From NMR Wiki
3D HSQC-TOCSY-NOESY-HSQC experiment [1] designed for 15N labeled proteins with poor dispersion of 1H chemical shifts and correlates chemical shifts of amide 15N with those of 1H and 15N atoms of nearby (most often sequential residue's) amide group.
Coherence follows the following pathway: H15N -- inept --> H15N (ω1) -- TOCSY --> Hα -- NOE --> H15N -- inept --> H15N (ω2) -- inept --> H (ω3)15N
Two of the three dimensions record 15N chemical shift which is usually dispersed better then 1H shift. HSQC-TOCSY-NOESY-HSQC works best with β-sheet proteins where TOCSY transfer H-N-Ca-Ha is more efficient.
References
- Zhang, O and Kay, LE and Olivier, JP and Forman-Kay, JD. Backbone 1 H and 15 N resonance assignments of the N-terminal SH3 domain of drk in folded and unfolded states using enhanced-sensitivity pulsed field gradient NMR techniques. Journal of Biomolecular NMR 4(6):845--858, 1994. BibTeX