13C-NMR relaxation in glycogen

✍ Scribed by Kristen Overloop; Florent Vanstapel; Paul Van Hecke

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 681 KB
• Volume: 36
• Category: Article
• ISSN: 0740-3194
• DOI: 10.1002/mrm.1910360109

✦ Synopsis

Abstract

This study is the first report on the multiexponential T~2~ relaxation of the ^13^C‐1 carbon of glycogen. In contrast to T~1~ relaxation, which does not display observable multiexponential decay behavior, T~2~ relaxation is described by a continuous distribution of T~2~ times. Changes in molecular weight and sample viscosity, which affect the overall mobility of the glycogen particle have little influence on T~1~ and T~2~ relaxation times. This is in contradiction with earlier results that T~2~ is dominated by the overall motion of the glycogen particles [L.‐H. Zang Biochemistry 29, 6815–6820 (1990)]. T~1~ depends strongly on the external field B~o~ and is almost temperature independent in the range 23–37°C whereas T~2~ is field independent and varies appreciably with temperature. The experimental T~1~ and T~2~ relaxation data are shown to be consistent with existing theoretical models for relaxation, suitably modified to include a distribution of correlation times for the internal motions. The presence of fast decaying components (short T~2~) in the FID implies broad line components in the frequency spectrum and the corresponding need to appropriately set the integration limits for the quantification of the glycogen peak.