Determination of the degree of esterification and the distribution of methylated and free carboxyl groups in pectins by 1H-n.m.r. spectroscopy

Grasdalen, Hans; Bakøy, O. E.; Lársen, Bjørn

doi:10.1016/0008-6215(88)80016-8

Cited by 112 publications

(26 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…DM was determined by integrating the spectral regions of H5 for the nonmethylesterified and methylesterified peaks that were fully resolved, as opposed to the other resonances. The assignments correspond to proton resonances previously reported (Grasdalen et al, 1988;Rosenbohm et al, 2003). Corresponding 13 C resonances were identified by recording two-dimensional 1 H-13 C spectra of 95% methyl-esterified citrus pectin and poly GalUA (both from Sigma-Aldrich).…”

Section: Nmrsupporting

confidence: 58%

Pectin Methyl Esterase Inhibits Intrusive and Symplastic Cell Growth in Developing Wood Cells ofPopulus

et al. 2007

View full text Add to dashboard Cite

Wood cells, unlike most other cells in plants, grow by a unique combination of intrusive and symplastic growth. Fibers grow in diameter by diffuse symplastic growth, but they elongate solely by intrusive apical growth penetrating the pectin-rich middle lamella that cements neighboring cells together. In contrast, vessel elements grow in diameter by a combination of intrusive and symplastic growth. We demonstrate that an abundant pectin methyl esterase (PME; EC 3.1.1.11) from wood-forming tissues of hybrid aspen (Populus tremula 3 tremuloides) acts as a negative regulator of both symplastic and intrusive growth of developing wood cells. When PttPME1 expression was up-and down-regulated in transgenic aspen trees, the PME activity in wood-forming tissues was correspondingly altered. PME removes methyl ester groups from homogalacturonan (HG) and transgenic trees had modified HG methylesterification patterns, as demonstrated by two-dimensional nuclear magnetic resonance and immunostaining using PAM1 and LM7 antibodies. In situ distributions of PAM1 and LM7 epitopes revealed changes in pectin methylesterification in transgenic trees that were specifically localized in expanding wood cells. The results show that en block deesterification of HG by PttPME1 inhibits both symplastic growth and intrusive growth. PttPME1 is therefore involved in mechanisms determining fiber width and length in the wood of aspen trees.

show abstract

Section: Nmrsupporting

confidence: 58%

Pectin Methyl Esterase Inhibits Intrusive and Symplastic Cell Growth in Developing Wood Cells ofPopulus

et al. 2007

View full text Add to dashboard Cite

show abstract

“…The cell wall was then separated into polymers rendered soluble by reduction and those extracted sequentially with 0.1 and 1.0 M NaOH. Studies using both 'H and 13C NMR spectroscopy have shown that methyl groups are stoichiometric with the esterified uronic acid in plant pectins (15,23). Maness et al (20) also reported good agreement for the percentage of pectin methyl ester determined colorimetrically and by reduction with NaBH4.…”

Section: Analysis Of the 66-dideuteriosugars By Gc-msmentioning

confidence: 97%

Changes in Esterification of the Uronic Acid Groups of Cell Wall Polysaccharides during Elongation of Maize Coleoptiles

Kim

Carpita²

1992

Plant Physiol.

314

201

View full text Add to dashboard Cite

Cell walls of grasses have two major polysaccharides that contain uronic acids, the hemicellulosic glucuronoarabinoxylans and the galactosyluronic acid-rich pectins. A technique whereby esterified uronic acid carboxyl groups are reduced selectively to yield their respective 6,6-dideuterio neutral sugars was used to determine the extent of esterification and changes in esterification of these two uronic acids during elongation of maize (Zea mays L.) coleoptiles. The glucosyluronic acids of glucuronoarabinoxylans did not appear to be esterified at any time during coleoptile elongation. The galactosyluronic acids of embryonal coleoptiles were about 65% esterified, but this proportion increased to nearly 80% during the rapid elongation phase before retuming to about 60% at the end of elongation. Methyl esters accounted for about two-thirds of the total esterified galacturonic acid in cell walls of unexpanded coleoptiles. Maness et al. (20) developed an elegant procedure for indirect determination of the total uronic acid units that are esterified. The methoxy group, or any other substitution, is a good leaving group for reduction by sodium borohydride of the esters to aldehydes and, subsequently, to their respective neutral sugars. We modified this technique slightly to reduce the carboxylic esters in imidazole buffer with sodium borodeuteride to generate 6,6-dideuteriosugars, which we could distinguish from nascent neutral sugars by GC-EIMS of their alditol acetates (Fig. 1). The free uronic acids are not reduced, but after preliminary reduction of the esters, the sample is divided into two fractions. In the first fraction, the remaining uronic acids are activated with a carbodiimide and reduced with sodium borodeuteride to give total uronic acid in the presence of nascent sugar. The second fraction is reduced with sodium borohydride to yield the proportion of esterified uronic acids when compared to the total sugar acids. This technique revealed that the GlcA units of the grass arabinoxylans were not capable of being reduced by NaBD4 alone at any stage of coleoptile elongation and, hence, did not appear to be esterified. The GalA units were esterified, and the apparent degree of esterification increased during the rapid phase of elongation and decreased slightly when growth ceased. To our surprise, however, the proportion of methyl esters decreased slightly during elongation and was not associated with the increase and decrease during elongation in the apparent esterified GalA revealed by reduction with NaBD4. In this report, we document the alterations in apparent ester-646 www.plantphysiol.org on May 11, 2018 -Published by Downloaded from

show abstract

“…The degree of methyl esterification (DE) was determined by 1 H NMR spectroscopy according Grasdalen, Bakoy, & Larsen (1988). Briefly, the fraction was deuterium-exchanged three times by freeze-drying with D 2 O solutions, finally dissolved in D 2 O, transferred into 5-mm NMR tube.…”

Section: Nuclear Magnetic Resonance (Nmr) Spectroscopymentioning

confidence: 99%

Arabinan-rich pectic polysaccharides from buriti (Mauritia flexuosa): An Amazonian edible palm fruit

Cantu-Jungles

Almeida

Iacomini

et al. 2015

Carbohydrate Polymers

View full text Add to dashboard Cite

Determination of the degree of esterification and the distribution of methylated and free carboxyl groups in pectins by 1H-n.m.r. spectroscopy

Cited by 112 publications

References 14 publications

Pectin Methyl Esterase Inhibits Intrusive and Symplastic Cell Growth in Developing Wood Cells ofPopulus

Pectin Methyl Esterase Inhibits Intrusive and Symplastic Cell Growth in Developing Wood Cells ofPopulus

Changes in Esterification of the Uronic Acid Groups of Cell Wall Polysaccharides during Elongation of Maize Coleoptiles

Arabinan-rich pectic polysaccharides from buriti (Mauritia flexuosa): An Amazonian edible palm fruit

Contact Info

Product

Resources

About