title: Pulse design for broadband correlation NMR spectroscopy by multi-rotating frames.
abstract: We present a method for designing radio-frequency (RF) pulses for broadband or multi-band isotropic mixing at low power, suitable for protein NMR spectroscopy. These mixing pulses are designed analytically, rather than by numerical optimization, by repeatedly constructing new rotating frames of reference. We show how pulse parameters can be chosen frame-by-frame to systematically reduce the effective chemical shift bandwidth, but maintain most of the effective J-coupling strength. The effective Hartmann-Hahn mixing condition is then satisfied in a multi-rotating frame of reference. This design method yields multi-band and broadband mixing pulses at low RF power. In particular, the ratio of RF power to mixing bandwidth for these pulses is lower than for existing mixing pulses, such as DIPSI and FLOPSY. Carbon-carbon TOCSY experiments at low RF power support our theoretical analysis.
authors: School of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02318, USA. pcoote@fas.harvard.edu
authors: Paul
authors: P
authors: Coote
authors: Haribabu
authors: H
authors: Arthanari
authors: Tsyr-Yan
authors: TY
authors: Yu
authors: Amarnath
authors: A
authors: Natarajan
authors: Gerhard
authors: G
authors: Wagner
authors: Navin
authors: N
authors: Khaneja
mesh_terms: D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008962:Models, Theoretical; D010455:Peptides / Q000737:chemistry; D011994:Recombinant Proteins / Q000737:chemistry
chemical_list: D010455:Peptides; D011994:Recombinant Proteins