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Multidimensional solid‐state NMR studies of the structure and dynamics of pectic polysaccharides in uniformly 13 C‐labeled Arabidopsis primary cell walls
Author(s) -
Pérez García Marilú,
Wang Tuo,
Salazar Andre,
Zabotina Olga A.,
Hong Mei
Publication year - 2012
Publication title -
magnetic resonance in chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.483
H-Index - 72
eISSN - 1097-458X
pISSN - 0749-1581
DOI - 10.1002/mrc.3836
Subject(s) - chemistry , polysaccharide , pectin , intermolecular force , cell wall , crystallography , solid state nuclear magnetic resonance , magic angle spinning , nmr spectra database , molecule , nuclear magnetic resonance spectroscopy , chemical physics , nuclear magnetic resonance , spectral line , stereochemistry , organic chemistry , biochemistry , physics , astronomy
Plant cell wall (CW) polysaccharides are responsible for the mechanical strength and growth of plant cells; however, the high‐resolution structure and dynamics of the CW polysaccharides are still poorly understood because of the insoluble nature of these molecules. Here, we use 2D and 3D magic‐angle‐spinning (MAS) solid‐state NMR (SSNMR) to investigate the structural role of pectins in the plant CW. Intact and partially depectinated primary CWs of Arabidopsis thaliana were uniformly labeled with 13 C and their NMR spectra were compared. Recent 13 C resonance assignment of the major polysaccharides in Arabidopsis thaliana CWs allowed us to determine the effects of depectination on the intermolecular packing and dynamics of the remaining wall polysaccharides. 2D and 3D correlation spectra show the suppression of pectin signals, confirming partial pectin removal by chelating agents and sodium carbonate. Importantly, higher cross peaks are observed in 2D and 3D 13 C spectra of the depectinated CW, suggesting higher rigidity and denser packing of the remaining wall polysaccharides compared with the intact CW. 13 C spin–lattice relaxation times and 1 H rotating‐frame spin–lattice relaxation times indicate that the polysaccharides are more rigid on both the nanosecond and microsecond timescales in the depectinated CW. Taken together, these results indicate that pectic polysaccharides are highly dynamic and endow the polysaccharide network of the primary CW with mobility and flexibility, which may be important for pectin functions. This study demonstrates the capability of multidimensional SSNMR to determine the intermolecular interactions and dynamic structures of complex plant materials under near‐native conditions. Copyright © 2012 John Wiley & Sons, Ltd.