Frequency-swept HMQC sequences for high-throughput NMR analysis.
We describe here new versions of the DEPT phase-encoded HMQC experiment that offer robust performance and improved sensitivity. The new sequences rely on frequency-swept proton and carbon pulses to minimize signal losses from miscalibrated pulses while providing 'J compensation' to optimize the signal strength over a range of heteronuclear coupling constants. By including both proton and carbon-swept pulses, the new sequences also offer an additional signal gain of roughly 10% over well-calibrated hard-pulse experiments. The new sequences also demonstrate that one can construct a sequence that incorporates both 90 degrees and 180 degrees frequency-swept pulses. Although individual pulses in the sequence cause severe phase roll, the phase roll can be eliminated by the proper choice of pulse lengths and sweep directions.
Spitzer
Timothy D
TD
GlaxoSmithKline, 5 Moore Drive, Research Triangle Park, NC 27707, USA. timothy.d.spitzer@gsk.com
Rutkowske
Randy D
RD
Dorsey
George F
GF
D000465:Algorithms; D002247:Carbon Isotopes / Q000737:chemistry; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D011522:Protons; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted
D002247:Carbon Isotopes; D011522:Protons