کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5406797 | 1506049 | 2009 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
EPIC- and CHANCE-HSQC: Two 15N-photo-CIDNP-enhanced pulse sequences for the sensitive detection of solvent-exposed tryptophan
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موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
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چکیده انگلیسی
Photochemically induced dynamic nuclear polarization (photo-CIDNP) of nuclei other than 1H offers a tremendous potential for sensitivity enhancement in liquid state NMR under mild, physiologically relevant conditions. Photo-CIDNP enhancements of 15N magnetization are much larger than those typically observed for 1H. However, the low gyromagnetic ratio of 15N prevents a full fruition of the potential signal-to-noise gains attainable via 15N photo-CIDNP. Here, we propose two novel pulse sequences, EPIC- and CHANCE-HSQC, tailored to overcome the above limitation. EPIC-HSQC exploits the strong 1H polarization and its subsequent transfer to non-equilibrium Nz magnetization prior to 15N photo-CIDNP laser irradiation. CHANCE-HSQC synergistically combines 1H and 15N photo-CIDNP. The above pulse sequences, tested on tryptophan (Trp) and the Trp-containing protein apoHmpH, were found to display up to 2-fold higher sensitivity than the reference NPE-SE-HSQC pulse train (based on simple 15N photo-CIDNP followed by N-H polarization transfer), and up to a ca. 3-fold increase in sensitivity over the corresponding dark pulse schemes (lacking laser irradiation). The observed effects are consistent with the predictions from a theoretical model of photo-CIDNP and prove the potential of 15N and 1H photo-CIDNP in liquid state heteronuclear correlation NMR.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Magnetic Resonance - Volume 200, Issue 2, October 2009, Pages 207-213
Journal: Journal of Magnetic Resonance - Volume 200, Issue 2, October 2009, Pages 207-213
نویسندگان
Ashok Sekhar, Silvia Cavagnero,