“Double-WURST” Decoupling for15N- and13C-Double-Labeled Proteins in a High Magnetic Field

✍ Scribed by Shanmin Zhang; Jian Wu; David G. Gorenstein

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 204 KB
• Volume: 123
• Category: Article
• ISSN: 1064-1858
• DOI: 10.1006/jmra.1996.0233

✦ Synopsis

A ''Double-WURST'' decoupling sequence is constructed for sitogether with suitable phase cycles, mainly to compensate multaneously decoupling the 13 CO and 13 C a regions in 15 N/ 13 C-doupulse imperfections.

ble-labeled proteins. It uses frequency-shifted WURST decoupling

The early design of broadband decoupling sequences is combined with standard WURST decoupling. The power can be based on Fourier analysis, which is quite intuitive but not reduced by two-thirds compared to conventional WURST decoualways successful since the spin system is, by nature, not a pling, which decouples the entire 13 C region including the unneeded linear system. A general decoupling theory was presented region between 13 CO and 13 C a . Well-decoupled spectra are acquired by Waugh (6) based on coherent average-Hamiltonian theusing the Double-WURST decoupling sequence with a test 15 N/ 13 Cory (7). A good broadband decoupling sequence must have double-labeled peptide sample and 8 and 19.6 kDa 15 N/ 13 C-doublean average Hamiltonian labeled proteins. It has also been shown that adiabatic decoupling, WURST, for example, has already reached its highest decoupling index n (Å2) defined in a relation of decouple range D f versus RF

where l is a constant. For n greater than 2, the energy conservation law would be violated, and for offsets D f from zero to as large as possible and a RF therefore is not possible.