SCUBA

SCUBA - stimulated cross peak under bleached alphas.

SCUBA[1] is a method of water suppression applicable for macromolecules that avoids a problem of bleaching signals that overlap with water resonance (such as Hα protons in the proteins). Method works for systems where T2 $\ll$ T1. A value of 60 ms was used for human ubiquitin at 500 MHz.

Figure above illustrates preparation sequence incorporating SCUBA element. Delay τ must be < T1.

References

1. BROWN, SC and WEBER, PL and MUELLER, L. Toward complete 1H NMR spectra in proteins. Journal of magnetic resonance 77(1):166--169, 1988. BibTeX [scuba]