Elimination of spin diffusion effects in saturation transfer experiments: application to hydrogen exchange in proteins.
The NMR saturation transfer experiment is widely used to characterize exchange processes in proteins that take place on the ms-s timescale. However, spin diffusion effects are inherently associated with the saturation transfer experiment and may overshadow the effect of the exchange processes of interest. As shown here, the effects from spin diffusion and exchange processes can be separated by varying the field strength of the saturation pulse, thereby allowing correct exchange rates to be obtained. The method is demonstrated using the hydrogen exchange process in the protein Escherichia coli thioredoxin as an example.
Jensen
Malene Ringkjøbing
MR
Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark.
Kristensen
Søren M
SM
Led
Jens J
JJ
D004926:Escherichia coli / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods* / Q000592:standards*; D012015:Reference Standards; D012680:Sensitivity and Specificity; D013879:Thioredoxins / Q000737:chemistry*
D013879:Thioredoxins; D006859:Hydrogen