HRMAS: 1H-13C HSQC T2 measurement in u-13C,15N KcsA

Measuring T2 by using fitting residual 1H-13C dipolar coupling.

Citation

A.G. Palmer III, J. Cavanagh, P.E. Wright & M. Rance, J. Magn. Reson. 93, 151-170 (1991) https://www.sciencedirect.com/science/article/pii/002223649190036S L.E. Kay, P. Keifer & T. Saarinen, J. Am. Chem. Soc. 114, 10663-5 (1992) (https://pubs.acs.org/doi/abs/10.1021/ja00052a088](https://pubs.acs.org/doi/abs/10.1021/ja00052a088) J. Schleucher, M. Schwendinger, M. Sattler, P. Schmidt, O. Schedletzky, S.J. Glaser, O.W. Sorensen & C. Griesinger, J. Biomol. NMR 4, 301-306 (1994) [https://www.ncbi.nlm.nih.gov/pubmed/8019138]https://www.ncbi.nlm.nih.gov/pubmed/8019138) S. Grzesiek & A. Bax, J. Am. Chem. Soc. 115, 12593-12594 (1993) https://pubs.acs.org/doi/abs/10.1021/ja00079a052

Protocol

Samples

The experiments were performed with a precipitated U-13C/15N KcsA, LPR =1, 9:1 DOPE-DOPS D2O citrate buffer pH 7.5

Processing and analysis

Use NMRGLUE for processing. T2 exponential decay is modulated by 13C-1H residual dipolar coupling. It is possible to either fit it using a numerical solution (Fresnel integral in equation 1 in Fritzsching et). Alternately, you can collect enough points to do an FT and measure dipolar coupling exactly.

Citations.

J.J. Helmus, C.P. Jaroniec, Nmrglue: An open source Python package for the analysis of multidimensional NMR data, J. Biomol. NMR 2013, 55, 355-367. https://link.springer.com/article/10.1007%2Fs10858-013-9718-x Fritzsching et al Avoidance of Density Anomalies as a Structural Principle for Semicrystalline polymers. Macromolecules 2017, 50, 1521-1540 https://pubs.acs.org/doi/10.1021/acs.macromol.6b02000

Pulse Sequence and Parameter Set