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Signal enhancement in protein NMR using the spin-noise tuning optimum.

Nausner M, Goger M, Bendet-Taicher E, Schlagnitweit J, Jerschow A, Müller N - J. Biomol. NMR (2010)

Bottom Line: The method requires the adjustment of the optimal tuning condition, which may be offset by several 100 kHz from the conventional tuning settings using the noise response of the water protons as an indicator.Although the radio frequency-pulse durations are typically longer under such conditions, signal-to-noise gains of up to 22% were achieved.At salt concentrations up to 100 mM a substantial sensitivity gain was observed.

View Article: PubMed Central - PubMed

Affiliation: Institute of Organic Chemistry, Johannes Kepler University, Linz, Austria.

ABSTRACT
We have assessed the potential of an alternative probe tuning strategy based on the spin-noise response for application in common high-resolution multi-dimensional biomolecular NMR experiments with water signal suppression on aqueous and salty samples. The method requires the adjustment of the optimal tuning condition, which may be offset by several 100 kHz from the conventional tuning settings using the noise response of the water protons as an indicator. Although the radio frequency-pulse durations are typically longer under such conditions, signal-to-noise gains of up to 22% were achieved. At salt concentrations up to 100 mM a substantial sensitivity gain was observed.

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First [1H 15N] plane of a HNCA spectrum acquired on a 500 MHz spectrometer with a cryogenically cooled triple resonance probe (a). In analogy to Fig. 3b 1D traces of selected signals and S/N ratios are displayed under SNTO (in red) and WO conditions (black) (b). In analogy to Fig. 3c and d S/N of the TopSpin peak lists are displayed under SNTO (in red) and WO conditions (black) (c), with the resulting S/N gain and the average signal enhancement of 21.8% under SNTO conditions (d)
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Fig4: First [1H 15N] plane of a HNCA spectrum acquired on a 500 MHz spectrometer with a cryogenically cooled triple resonance probe (a). In analogy to Fig. 3b 1D traces of selected signals and S/N ratios are displayed under SNTO (in red) and WO conditions (black) (b). In analogy to Fig. 3c and d S/N of the TopSpin peak lists are displayed under SNTO (in red) and WO conditions (black) (c), with the resulting S/N gain and the average signal enhancement of 21.8% under SNTO conditions (d)

Mentions: All protein experiments were performed on doubly labeled (15N and 13C) ubiquitin (500 μM) in 50 mM ammonium acetate buffer, pH 4.5, no added salt, both at the SNTO and at the WO for comparison (a sample temperature of 302.2 K, rf-coil temperature 30.5 K). The displayed spectra (Figs. 3, 4, 5, 6) were acquired on a Bruker Avance spectrometer at 500 MHz equipped with cryogenically cooled triple resonance probe optimized for proton detection (TXI) using conditions detailed in Table 1. The 3D pulse sequences used [original HNCO and HNCA sequence by Kay et al. 1990, original CBCA(CO)NH sequence by Grzesiek and Bax 1992a, actual HNCA and HNCO sequence (hncagpwg3d, hncogpwg3d from the Bruker library) by Grzesiek and Bax (1992b), Schleucher et al. (1993), Kay et al. (1994), and Davis et al. (1992), actual CBCA(CO)NH sequence (cbcaconhgpwg3d from the Bruker library) by Grzesiek and Bax (1993), and Muhandiram and Kay (1994)] used WATERGATE (Sklenar et al. 1993) solvent signal suppression. In all 3D experiments the receiver gain was set to 1,024, which is far above the digitization noise limit.Fig. 3


Signal enhancement in protein NMR using the spin-noise tuning optimum.

Nausner M, Goger M, Bendet-Taicher E, Schlagnitweit J, Jerschow A, Müller N - J. Biomol. NMR (2010)

First [1H 15N] plane of a HNCA spectrum acquired on a 500 MHz spectrometer with a cryogenically cooled triple resonance probe (a). In analogy to Fig. 3b 1D traces of selected signals and S/N ratios are displayed under SNTO (in red) and WO conditions (black) (b). In analogy to Fig. 3c and d S/N of the TopSpin peak lists are displayed under SNTO (in red) and WO conditions (black) (c), with the resulting S/N gain and the average signal enhancement of 21.8% under SNTO conditions (d)
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2962798&req=5

Fig4: First [1H 15N] plane of a HNCA spectrum acquired on a 500 MHz spectrometer with a cryogenically cooled triple resonance probe (a). In analogy to Fig. 3b 1D traces of selected signals and S/N ratios are displayed under SNTO (in red) and WO conditions (black) (b). In analogy to Fig. 3c and d S/N of the TopSpin peak lists are displayed under SNTO (in red) and WO conditions (black) (c), with the resulting S/N gain and the average signal enhancement of 21.8% under SNTO conditions (d)
Mentions: All protein experiments were performed on doubly labeled (15N and 13C) ubiquitin (500 μM) in 50 mM ammonium acetate buffer, pH 4.5, no added salt, both at the SNTO and at the WO for comparison (a sample temperature of 302.2 K, rf-coil temperature 30.5 K). The displayed spectra (Figs. 3, 4, 5, 6) were acquired on a Bruker Avance spectrometer at 500 MHz equipped with cryogenically cooled triple resonance probe optimized for proton detection (TXI) using conditions detailed in Table 1. The 3D pulse sequences used [original HNCO and HNCA sequence by Kay et al. 1990, original CBCA(CO)NH sequence by Grzesiek and Bax 1992a, actual HNCA and HNCO sequence (hncagpwg3d, hncogpwg3d from the Bruker library) by Grzesiek and Bax (1992b), Schleucher et al. (1993), Kay et al. (1994), and Davis et al. (1992), actual CBCA(CO)NH sequence (cbcaconhgpwg3d from the Bruker library) by Grzesiek and Bax (1993), and Muhandiram and Kay (1994)] used WATERGATE (Sklenar et al. 1993) solvent signal suppression. In all 3D experiments the receiver gain was set to 1,024, which is far above the digitization noise limit.Fig. 3

Bottom Line: The method requires the adjustment of the optimal tuning condition, which may be offset by several 100 kHz from the conventional tuning settings using the noise response of the water protons as an indicator.Although the radio frequency-pulse durations are typically longer under such conditions, signal-to-noise gains of up to 22% were achieved.At salt concentrations up to 100 mM a substantial sensitivity gain was observed.

View Article: PubMed Central - PubMed

Affiliation: Institute of Organic Chemistry, Johannes Kepler University, Linz, Austria.

ABSTRACT
We have assessed the potential of an alternative probe tuning strategy based on the spin-noise response for application in common high-resolution multi-dimensional biomolecular NMR experiments with water signal suppression on aqueous and salty samples. The method requires the adjustment of the optimal tuning condition, which may be offset by several 100 kHz from the conventional tuning settings using the noise response of the water protons as an indicator. Although the radio frequency-pulse durations are typically longer under such conditions, signal-to-noise gains of up to 22% were achieved. At salt concentrations up to 100 mM a substantial sensitivity gain was observed.

Show MeSH
Related in: MedlinePlus