Cell wall polysaccharide

A polysaccharide-fatty acid complex isolated from the surface of cells of Candida tropicalis (a yeast that grows on aliphatic hydrocarbons) is considered to form part of the hydrocarbon-binding system. By comparison with other yeasts of the same genus, the cell walls of a Candida strain growing on aliphatic hydrocarbons contain less neutral sugars but more proteins and 2-amino-2-deoxy-D-glucose part of the amino-sugar occurs as chitin, which represents 22 % of the constituents of the cell wall.  

Studies with partially purified glycosidases have confirmed the presence of chitin and (1 - 3)-p-D-glucan in the cell walls of Histoplasma capsulatum chemo- 

Electron microscopy has revealed that there are two distinct layers in the cell walls of conidia and chlamydospores from Fusarium sulphureum The amounts of D-glucose and 2-acetamido-2-deoxy-D-glucose incorporated into polymers in the innermost layer increases appreciably during the differentiation of conidia to chlamydospores. D-Glucuronic acid is also found in polysaccharides from both layers. 

Immunochemical studies on galactomannans isolated from the mycelia and culture media of Hormodendrum pedrosoi, H. compactum, and H. dermatitidis have indicated that acid-labile D-galactofuranosyl residues are responsible for precipitating antibodies. The galactomannans and their respective core components precipitated anti-(5. cerevisiae) serum, which interacts only with (1 6)- 

When incubated under appropriate conditions with tritiated L-methionine, Mycobacterium smegmatis accumulates significant amounts of labelled oligo- 

An acidic arabino-D-mannan isolated from M. smegmatis also contains two phosphate, six monoesterified succinate, and four ether-linked lactate groups per molecule.Saponification of the polysaccharide releases a phosphorylated- and a non-phosphorylated polysaccharide, the main features of which are the presence of chains of contiguous (1 5)-arabinofuranosyl residues attached to 0-4 of L-arabinopyranosyl residues. A serologically active D-arabino-D-mannan, isolated from the cells of M. tuberculosis, is composed of (1 5)-a-D-arabino-furanosyl residues and (1 6)- and (1 2)-D-mannopyranosyl residues.  

Methylation analysis and enzymic degradation studies established the presence of a structure (23) containing short side-chains of (1 - 2)-at-D-mannosyl residues attached to a main backbone of (1 6)-ot-D-mannopyranosyl residues. In addition, a serologically inactive a-D-mannan whose structure (24) resembles that of the core L-arabino-D-mannan has been isolated. 

In addition to a high molecular weight lipopolysaccharide, the cell surface of Rhizobium contains a low molecular weight (1 2)-/3-D-glucan. Curie point 

Antibodies to a heteroglycan of Streptococcus bovis have been purified by an affinity chromatographic method. 

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G. O. AspiuaU, iu F. Loewus ed.. Biogenesis of Plant Cell Wall Polysaccharides, Academic Press, Inc., New York, 1973. 

The presence and biological importance of oligosaccharide structures, usually as components of glycolipids and glycoproteins, in bacterial capsular and cell-wall polysaccharides, in mammalian cell membranes, in cytoplasm, and in extracellular fluids, are now well documented. They are important constituents in... 

Based on the current stage of knowledge, hemicelluloses can be divided into four general classes of structurally different cell-wall polysaccharide types, i.e.,... 

Within the scope of this review, the contributions of the last decade concerning cell-wall polysaccharides isolated from woody and other plant tissues will be reviewed according to the above-proposed classification of hemicelluloses including larch arabinogalactans. The present review article updates and extends previous reviews [3-5] and will focus in particular on new investigated plant sources, isolation methods, structural features, physicochemical and various functional properties of hemicelluloses. Attention will also be paid to the modification of isolated hemicelluloses or hemicellulosic materials and the appHcation possibiUties of hemicelluloses and their derivatives, including their use for the production of composite materials and other biomaterials. 

Figures 3 and 5 from Biochimie, vol 85, Perez S, Rodrigues-Carvajal MA, Doco T (2003) A complex plant cell wall polysaccharide rhamnogalactmonan 11. A structure in quest of a function. p 109-pl21...

Three 3-amino-3,6-dideoxyhexoses, having the d- and L gluco and D-ga-lacto configurations, have been found. The two D-sugars are not very common, but occur in some 0-antigens for example, those from E. coli 0114 (Ref. 60) and E. coli 02 (Ref 61), respectively. The D-galacto isomer has also been found in the cell-wall polysaccharide from Eubacterium saburreum strain L13.3-Amino-3,6-dideoxy-L-glucose has been found in the core part of the Aeromonas hydrophila chemotype 111 LPS. 

Several methylated sugars have been identified in hydrolyzates of LPS, cell-wall polysaccharides, and extracellular polysaccharides. A considerable number of these have been found in the LPS from photosynthetic prokaryotes. Two polysaccharides from Mycobacterium species, a glucan" and a mannan" are remarkable in that they contain high percentages of methylated sugars. Glycolipids from Mycobacterium species are also rich in methylated sugars, some of which have not been found elsewhere, but this is beyond the scope of the present article. 

Other galacturonic acid-containing plant cell wall polysaccharides... 

We hypothesize that the fundamental processes of cell wall expansion are conserved in all higher plants, that is, growth of the cells of all higher plants requires the synthesis and insertion of the same polysaccharides by the same procedures. If this hypothesis is correct, then all primary cell walls have a common set of stmctural polysaccharides. The commonality of the primary cell wall polysaccharides hypothesis does not require that (i) the common polysaccharides be present in all cell walls in the same proportions, (ii) the polysaccharides be... 

This essay was written in an attempt to explain our overview of primary cell walls and to reach consensus on the nomenclature of primary cell wall polysaccharides. We present evidence supporting the hypothesis that cellulose, xyloglucan, arabinoxylan, homogalacturonan, RG-I, and RG-II are the six polysaccharides common to all primary cell walls of higher plants. In many cells, these six polysaccharides account for all or nearly all of the primary wall polysaccharides. Like the physically interacting proteins that constitute the electron transport machinery of mitochondria, the structures of the six patently ubiquitous polysaccharides of primary cell walls have been conserved during evolution. Indeed, we hypothesize that the common set of six structural polysaccharides of primary cell walls have been structurally... 

This paper begins with a brief description of pectin structure and an overview of the general mechanism of cell wall polysaccharide biosynthesis. This is followed by a summary of previous research on PGA-GalAT and a description of a facile method to synthesize UDP-[ Cj-galacturonic acid. Finally, the paper ends with a summary of our work on the identificadon, partial characterization, and initial solubilization of the homogalacturonan biosynthetic enzyme PGA-GalAT. 

General mechanisms of plant cell wall polysaccharide biosynthesis... 

Gibeaut, D.M. and Carpita, N.C. (1994) Biosynthesis of plant cell wall polysaccharides. 

Finally, the A. aculeatus preparation was found to contain an enzyme releasing the dimer B-Xylp-(l-3)-GalAj, from a soluble soy cell wall polysaccharide. The enzyme was partially purified and appeared to be active towards saponified MHR and gum tragacanth as well. It was concluded that this enzyme degraded the xylogalacturonan part in MHR by an exo-fashion. 

A cell-wall polysaccharide fraction remaining after treatment with a "classical" pectinase is termed rhamnogalacturonan (RG) or modified hairy regions (MHR). It is characterized by a highly branched ihamnogalacturonan-polymer with some arabinan side chains. 

Isolation and sequential extraction of cell wall polysaccharides from soy meal... 

The objective of the project described is to obtain insight in the relation between the chemical fine-structure of polysaccharides from soy bean cell walls and their functional properties in industrial products and how they effect processing. Soy meal is of great importance in the feed industry. The application of the (modified) soy bean cell wall polysaccharides as a food additive will be investigated. The obtained knowledge of the polysaccharide structures will also be used in studies concerned with the improvement of the in vivo digestibility of these polysaccharides. 

The yield and the composition of the fractions from soy bean meal obtmned with isolating WUS is shown in Table 1. The removal of cold water solubles, proteins and starch from soy meal was successful. The larger part of the material appeared in CWS, 59.1%. UFF contained mainly oligosaccharides and some water soluble proteins and UFR contained mainly water soluble proteins. The solution of SDSS and DTT extracted the residual proteins from the soy meal and the extract consisted for over 80% of proteins. Since the yield of the HWS fraction is only 0.4%, the composition is not discussed here. The remaining WUS contained 90% of NSP and the yield was 15.7%, which indicates that from the polysaccharides present in soy meal 92% was recovered in the WUS. By isolating WUS a fraction is obtained in which almost all cell wall polysaccharides are recovered and which contained only little other components. 

Firmnes is, at least in part, related to the composition and structure of cell wall, therefore, from the point of view of controlling the process it is important to know the changes that take place on cell wall polysaccharides through it. 

The molecular weight distribution of cell wall polysaccharides was estimated by gel filtration with a TOSOH TSK gel G4000 PWXL (7.8 x 300 mm) column equilibrated and eluted with 0.05 M sodium acetate, 0.01 M EDTA, 0.05 M NaCl (pH 5.0) in polyuronide and 0.05 M sodium citrate, 0.1 M NaCl (pH 5.5) in the hemicellulose fraction. Samples (1 mg/ml) of 100 ml were injected. The eluate was monitored by a refractive index detector (Shimadzu R1D-6A, Kyoto, Japan) and collected at the fraction size of 0.4 ml. 

Kim, J-B., Caipita, N.C. (1992), Changes in esterification of the uronic acid groups of cell wall polysaccharides during elongation of maize coleoptiles. Plant Physiol. 98, 646-653. 

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