Quantitative Measurement of Transverse and Longitudinal Cross-Correlation between13C–1H Dipolar Interaction and13C Chemical Shift Anisotropy: Application to a13C-Labeled DNA Duplex

✍ Scribed by Chojiro Kojima; Akira Ono; Masatsune Kainosho; Thomas L. James

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 105 KB
• Volume: 136
• Category: Article
• ISSN: 1090-7807
• DOI: 10.1006/jmre.1998.1656

✦ Synopsis

Measurement of both longitudinal and transverse relaxation interference (cross-correlation) between 13C chemical shift anisotropy and 13C-1H dipolar interactions is described. The ratio of the transverse to longitudinal cross-correlation rates readily yields the ratio of spectral densities J(0)/J(omegaC), independent of any structural attributes such as internuclear distance or chemical shift tensor. The spectral density at zero frequency J(0) is also independent of chemical exchange effects. With limited internal motions, the ratio also enables an accurate evaluation of the correlation time for overall molecular tumbling. Applicability of this approach to investigating dynamics has been demonstrated by measurements made at three temperatures using a DNA decamer duplex with purines randomly enriched to 15% in 13C.