Quantitative Determination of Cross-Relaxation Rates in NMR Using Selective Pulses to Inhibit Spin Diffusion
✍ Scribed by Martina Schwager; Geoffrey Bodenhausen
- Publisher
- Elsevier Science
- Year
- 1996
- Tongue
- English
- Weight
- 236 KB
- Volume
- 111
- Category
- Article
- ISSN
- 1064-1866
No coin nor oath required. For personal study only.
✦ Synopsis
Overhauser effects and hence internuclear distances can be mea-Recently, we have proposed two new selective methods sured accurately with selective experiments designed to suppress to address these problems. The first method, which has been spin diffusion. It is essential to consider effects of both transverse dubbed quantitative unraveling of intensities for corroboratand longitudinal relaxation during selective radiofrequency pulses. ing knowledge in nuclear Overhauser effect spectroscopy Fitting procedures allow one to refine selected cross-relaxation (QUICK-NOESY) (4), yields the same information as tworate constants, and hence determine internuclear distances with dimensional NOESY, but allows one to record extensive improved accuracy. For the sake of illustration, selected crossbuildup curves within a reasonable time interval (Fig. 1,
rates are determined that correspond to short-and longtop). The second method, called quenching of undesirable range distances involving two diastereotopic sugar protons in a indirect external trouble in nuclear Overhauser effect specdouble-stranded B-DNA dodecamer. Such distances are difficult troscopy (QUIET-NOESY) (5), has a much more ambitious to distinguish by traditional Overhauser methods because of spinobjective, since it aims at suppressing spin-diffusion effects. diffusion effects.