Bruker NMR, User Manual

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Applications
28 Z33085_2_002
Figure 6.2: Overlay of 15N HSQC spectra (overview: left part) of 0.5 mM ubiquitin 9:1 H2O/D2O.
Identical Chemical Shifts for Experiments with Different
Heating due to Experimental Conditions (Temperature
Compensation)
The superior feature of the NMR Thermometer is the ability to compensate for sample
heating inside the sample due to different sources (RF heating, spinning speed, HR MAS).
RF Heating
RF heating inside the sample is caused by, for instance, a spinlock sequence as used in
TOCSY-type of pulse sequences, or decoupling as well as CPMG sequences. Such
experiments are widely used in biomolecular NMR. As an example we show a 0.5 mM
13 C-
and 15 N-labeled ubiquitin in H
2
O/D
2
O with sodium acetate-d
3
added as NMR Thermometer
substance. In the example the 2D HSQC-planes of 3D NOESY-HSQC, TOCSY-HSQC and
CPMG-HSQC experiments are compared. Reference planes were measured without
temperature compensation (figure below, left part) and the others with NMR Thermometer in
the regulation mode (figure below, right part).
6.2
6.2.1