Simple suppression of spurious peaks in TROSY experiments.
In (1)H-(15)N TROSY experiments of proteins and nucleic acids, where the second coherence transfer delay time tau' has been fixed as 5.6 ms, 1/(2(1)J(NH)), in order to achieve complete spin-state selection, spurious negative peaks are observed along the (15)N axes. These peaks are often annoyingly large, especially for nucleic acids. A simple product operator calculation, however, indicated that the shortening of the second delay time tau', which is next to the t1 period, would efficiently suppress these spurious peaks, without sacrificing the sensitivities of the TROSY peaks too much. We have shown for three systems, two 11- and 17-kDa proteins and one 8-kDa DNA duplex, that these spurious peaks can be effectively suppressed with delay times of 3.3 ms for the two proteins and 2.3 ms for the DNA. These delay times, optimized by trial and error, for the spurious peak suppression did not depend on the magnetic field strength and the temperature very much. Although the shortened tau' delay times attenuate the TROSY peak intensities by about 10 and 20% for the two proteins and the DNA, respectively, this simple modification will be useful for the quantitative uses of TROSY peaks and will result in cleaner spectra for various TROSY-based multiple resonance experiments.
Kojima
C
C
CREST, Japan Science and Technology Corporation, Department of Chemistry, Faculty of Science, Tokyo Metropolitan University, 1-1 Minami-ohsawa, Hachioji, Tokyo, 192-0392, Japan.
Kainosho
M
M
D002352:Carrier Proteins / Q000737:chemistry; D015891:Cystatins / Q000737:chemistry; D015853:Cysteine Proteinase Inhibitors / Q000737:chemistry; D004247:DNA / Q000737:chemistry; D004268:DNA-Binding Proteins / Q000737:chemistry; D004578:Electron Spin Resonance Spectroscopy; D024243:HMGB1 Protein; D006609:High Mobility Group Proteins / Q000737:chemistry; D018398:Homeodomain Proteins / Q000737:chemistry; D006859:Hydrogen; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008280:Magnetics; D008956:Models, Chemical; D009363:Neoplasm Proteins / Q000737:chemistry; D009419:Nerve Tissue Proteins / Q000737:chemistry; D009587:Nitrogen Isotopes; D009696:Nucleic Acids / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry*; D012680:Sensitivity and Specificity; D013696:Temperature; D013997:Time Factors
D002352:Carrier Proteins; D015891:Cystatins; D015853:Cysteine Proteinase Inhibitors; D004268:DNA-Binding Proteins; D024243:HMGB1 Protein; D006609:High Mobility Group Proteins; D018398:Homeodomain Proteins; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D009587:Nitrogen Isotopes; D009696:Nucleic Acids; D011506:Proteins; D006859:Hydrogen; D004247:DNA