This subproject is one of many research subprojects utilizing theresources provided by a Center grant funded by NIH/NCRR. The subproject andinvestigator (PI) may have received primary funding from another NIH source,and thus could be represented in other CRISP entries. The institution listed isfor the Center, which is not necessarily the institution for the investigator.NMR SpectroscopyThe sample (~1 mg) was deuterium-exchanged by lyophilization from D2O (99.9 % D), dissolved in 0.72 mL DMSO-d6 (99.9 % D) containing 2 % D2O (99.96 % D), and transferred to a 5 mm NMR tube. A 1-D Proton and a TOCSY NMR spectrum, both with water presaturation were acquired on a Varian Inova-800 MHz spectrometer at 308 K (35 C). The spectral width was 4819 Hz, and the pulse width was 8.6 ms. In the 1-D experiment, the acquisition time was 2.0 s, and 16 scans were collected. In the 2-D TOCSY experiment, the acquisition time was 0.21 s, 16 scans and 256 increments were collected with a mixing time of 60 ms. Chemical shifts were measured relative to the DMSO-d5 multiplet (d=2.50 ppm).A 36-mL aliquot of the above solution (=50 mg sample) was diluted with 0.6 mL DMSO-d6 (99.9 % D) containing 2 % D2O (99.96 % D) and transferred to a 5 mm NMR tube. A 1-D proton NMR spectrum using the WET presaturation sequence on both the water and the DMSO signals, a gradient enhanced 2-D COSY spectrum, and a low-resolution TOCSY with WET presaturation were acquired on the 800-MHz instrument at 308 K. The spectral width was 5997 Hz, and the pulse width was 8.5 ms. In the 1-D experiment, the acquisition time was 1.0 s, and 512 scans were collected. In the 2-D gCOSY experiment, the acquisition time was 0.34 s, 180 scans and 128 increments were collected, and in the TOCSY experiment, the acquisition time was 0.20 s, 48 scans and 64 increments were collected with a mixing time of 60 ms.
Showing the most recent 10 out of 245 publications
