Wood Hemicelluloses: Part II

Timell, T. E.

doi:10.1016/s0096-5332(08)60304-5

Cited by 127 publications

(86 citation statements)

References 89 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…3-and 2,5-linked arabinosyl residues present in fraction PG-IB may arise from the presence of a small amount of an arabinogalactan which is distinctly different from the arabinan and from the 4-linked galactan which we believe cross-links the xyloglucan and rhamnogalacturonan. This type of arabinogalactan is commonly found in coniterous woods (64) and in a number of plant gums (9) and is characterized by a branched trameworK of 3-and 6-linked galactosyl residues. The majority of the side chains in this type of arabinogalactan are single arabinofuranosyl residues.…”

Section: Discussionmentioning

confidence: 99%

“…Cellulose, hemicellulose, pectic polysaccharide, structural protein, and lignin have been identified as the major components of the plant cell wall. These components have been discussed in several recent reviews (4,9,26,35,47,52,63,64,68). Lignin is a characteristic component of secondary walls and is therefore not further discussed.…”

mentioning

confidence: 99%

“…The noncellulosic polysaccharides have been defined operationally by their presence in the fractions obtained by consecutive chemical extraction of isolated walls. The two major noncellulosic fractions are the pectic polysaccharides obtained by extracting cell walls with boiling water, EDTA, or dilute acid (9,70) and the hemicelluloses solubilized by the subsequent extraction of the same walls with alkali (63,64,68).…”

mentioning

confidence: 99%

“…The nature of the hemicelluloses isolated from different tissues varies con-siderably. Commonly occurring hemicelluloses include xylans, arabinoxylans, mannans, arabinogalactans, glucomannans, and galactoglucomannans (63,64,68).…”

mentioning

confidence: 99%

See 3 more Smart Citations

The Structure of Plant Cell Walls

Talmadge¹,

Keegstra²,

Bauer³

et al. 1973

Plant Physiol.

500

162

View full text Add to dashboard Cite

This is the first in a series of papers dealing with the structure of cell walls isolated from suspension-cultured sycamore cells (Acer pseudoplatanus) . These studies have been made possible by the availability of purified hydrolytic enzymes and by recent improvements in the techniques of methylation analysis. These techniques have permitted us to identify and quantitate the macromolecular components of sycamore cell walls. These walls are composed of 10% arabinan, 2% 3,6-linked arabinogalactan, 23% cellulose, 9 % oligo-arabinosides (attached to hydroxyproline), 8% 4-linked galactan, 10% hydroxyproline-rich protein, 16 % rhamnogalacturonan, and 21% xyloglucan.The structures of the pectic polymers (the neutral arabinan, the neutral galactan, and the acidic rhamnogalacturonan) were obtained, in part, by methylation analysis of fragments of these polymers which were released from the sycamore walls by the action of a highly purified endopolygalacturonase. The data suggest a branched arabinan and a linear 4-linked galactan occurring as side chains on the rhamnogalacturonan. Small amounts or pieces of a xyloglucan, the wall hemicellulose, appear to be covalently linked to some of the galactan chains. Thus, the galactan appears to serve as a bridge between the xyloglucan and rhamnogalacturonan components of the wall.The rhamnogalacturonan consists of an a-(1 -; 4)-linked galacturonan chain which is interspersed with 2-linked rham. nosyl residues. The rhamnosyl residues are not randomly distributed in the chain but probably occur in units of rhamnosyl-(1 -4 4)-galacturonosyl-(1 -e 2)-rhamnosyl. This sequence appears to alternate with a homogalacturonan sequence containing approximately 8 residues of 4-linked galacturonic acid. About half of the rhamnosyl residues are branched, having a substituent attached to carbon 4. This is likely to be the site of attachment of the 4-linked galactan.The hydroxyprolyl oligo-arabinosides of the hydroxyproline. rich glycoprotein contain 3-linked, 2-linked, and terminal arabinosyl residues. The structure of the hydroxyprolyl oligoarabinosides deduced from our methylation studies agrees with the structure reported for similar oligosaccharides. Cellulose, hemicellulose, pectic polysaccharide, structural protein, and lignin have been identified as the major components of the plant cell wall. These components have been discussed in several recent reviews (4,9,26,35,47,52,63,64,68). Lignin is a characteristic component of secondary walls and is therefore not further discussed.Crystalline cellulose fibers make up an important part of the framework of the cell walls of all higher plants. Electron microscopy and x-ray diffraction have led to a rather detailed description of the structure of this wall component (35,57,69

show abstract

Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

The Structure of Plant Cell Walls

Talmadge¹,

Keegstra²,

Bauer³

et al. 1973

Plant Physiol.

500

162

View full text Add to dashboard Cite

show abstract

“…It accounts for 20-35% of the approximately 830 gigatons of plant biomass formed annually (5,6). Unlike prokaryotic microorganisms, which have a xylose isomerase, most xylose-assimilating yeasts, including C. tropicalis, utilize D-xylose via two enzymatic oxidoreductive reactions, with xylose reductase (XR; EC 1.1.1.21) and xylitol dehydrogenase (XDH; EC 1.1.1.9), to form D-xylulose, which is converted to xylulose 5-phosphate by xylose kinase (XK) and then enters the pentose-phosphate pathway (7).…”

Section: Introductionmentioning

confidence: 99%

Molecular Cloning and Characterization of NAD⁺‐Dependent Xylitol Dehydrogenase from Candida tropicalis ATCC 20913

Kim

2006

Biotechnology Progress

View full text Add to dashboard Cite

Induction of xylitol dehydrogenase of Candida tropicalis ATCC 20913 by various carbon sources was investigated. The enzyme activity was induced when the yeast was grown on l‐arabinose and d‐xylose. A novel gene encoding the enzyme was cloned and characterized. The 1,095‐bp coding sequence of the gene encodes a polypeptide of 364 amino acids, with a molecular mass of 39.4 kDa. Sequence analysis of the putative protein showed it to be a member of the zinc‐containing alcohol dehydrogenase family and to have homology to xylitol dehydrogenase genes from other yeasts and fungi. The recombinant xylitol dehydrogenase expressed in Escherichia coli oxidized polyols such as xylitol and d‐sorbitol and reduced ketoses such as d‐xylulose and d‐fructose. It required exclusively NAD or NADH as a cofactor.

show abstract

A rapid and simple method to isolate pure alpha-cellulose

Brendel¹,

Iannetta²,

Stewart³

2000

Phytochem. Anal.

272

167

View full text Add to dashboard Cite

A protocol is described to isolate small quantities of highly purified cellulose for isotopic analysis of 10–100 mg samples of secondary (Pinus sylvestris L.) and primary (Rubus idaeus L.) plant cell wall material. Elemental analysis of 350 cellulose samples isolated from pine wood samples estimated the relative carbon content to be ca. 43.7% ± 1.2%. This value indicates that the cellulose quality is high and that the protocol is highly reproducible. High‐performance anion exchange chromatography with pulsed amperometric detection of hydrolysis products quantified the purity of the cellulose as ca. 99% for wood cellulose and primary cell wall cellulose. DRIFT spectroscopy corroborated this purity and found no evidence of cellulose degradation. Carbon isotopic composition of the purified cellulose using mass spectrometry was measured with an accuracy of 0.11‰ (standard deviation). The method is rapid (56 samples may be routinely processed within 8 h) and requires only standard laboratory equipment and chemicals. Copyright © 2000 John Wiley & Sons, Ltd.

show abstract

Wood Hemicelluloses: Part II

Cited by 127 publications

References 89 publications

The Structure of Plant Cell Walls

The Structure of Plant Cell Walls

Molecular Cloning and Characterization of NAD⁺‐Dependent Xylitol Dehydrogenase from Candida tropicalis ATCC 20913

A rapid and simple method to isolate pure alpha-cellulose

Contact Info

Product

Resources

About

Wood Hemicelluloses: Part II

Cited by 127 publications

References 89 publications

The Structure of Plant Cell Walls

The Structure of Plant Cell Walls

Molecular Cloning and Characterization of NAD+‐Dependent Xylitol Dehydrogenase from Candida tropicalis ATCC 20913

A rapid and simple method to isolate pure alpha-cellulose

Contact Info

Product

Resources

About

Molecular Cloning and Characterization of NAD⁺‐Dependent Xylitol Dehydrogenase from Candida tropicalis ATCC 20913