scholarly journals Hemicellulosic complexes from the cell walls of runner bean (Phaseolus coccineus)

1985 ◽  
Vol 227 (2) ◽  
pp. 475-481 ◽  
Author(s):  
M A O'Neill ◽  
R R Selvendran

The 1 M-KOH extract from the depectinated cell walls of parenchymatous tissues of mature runner bean (Phaseolus coccineus) on neutralization, dialysis and concentration gave insoluble (hemicellulose A) and soluble (hemicellulose B) carbohydrate complexes in the weight ratio 2:1. Both fractions contained polysaccharide, protein and polyphenolic material. The structural features of the carbohydrates were examined by methylation analysis. Hemicellulose A contained mainly pectic arabinogalactan, with lesser amounts of arabinoxylan and glucan. Sequential fractionation of hemicellulose B by anion-exchange and hydroxyapatite chromatography gave a range of polysaccharide-protein-polyphenolic complexes. The main polysaccharides in these complexes were (acidic) arabinoxylans, galactans, arabinogalactans 1 and 2 and xyloglucans. The proteins contained small amounts of hydroxyproline, but were rich in aspartic acid and glutamic acid. Attempts to determine the nature of the polyphenolic material were unsuccessful. The structural features of the polysaccharide-protein-polyphenolic complexes are discussed in relation to the structure of the cell walls of parenchymatous tissues.

1990 ◽  
Vol 269 (2) ◽  
pp. 393-402 ◽  
Author(s):  
P Ryden ◽  
R R Selvendran

1. Polymers were solubilized from the cell walls of parenchyma from mature runner-bean pods with minimum degradation by successive extractions with cyclohexane-trans-1,2-diamine-NNN′N′-tetra-acetate (CDTA), Na2CO3 and KOH to leave the alpha-cellulose residue, which contained cross-linked pectic polysaccharides and Hyp-rich glycoproteins. These were solubilized with chlorite/acetic acid and cellulase. The polymers were fractionated by anion-exchange chromatography, and fractions were subjected to methylation analysis. 2. The pectic polysaccharides differed in their ease of extraction, and a small proportion were highly cross-linked. The bulk of the pectic polysaccharides solubilized by CDTA and Na2CO3 were less branched than those solubilized by KOH. There was good evidence that most of the pectic polysaccharides were not degraded during extraction. 3. The protein-containing fractions included Hyp-rich and Hyp-poor glycoproteins associated with easily extractable pectic polysaccharides, Hyp-rich glycoproteins solubilized with 4M-KOH+borate, the bulk of which were not associated with pectic polysaccharides, and highly cross-linked Hyp-rich glycoproteins. 4. Isodityrosine was not detected, suggesting that it does not have a (major) cross-linking role in these walls. Instead, it is suggested that phenolics, presumably linked to C-5 of 3,5-linked Araf residues of Hyp-rich glycoproteins, serve to cross-link some of the polymers. 5. There were two main types of xyloglucan, with different degrees of branching. The bulk of the less branched xyloglucans were solubilized by more-concentrated alkali. The anomeric configurations of the sugars in one of the highly branched xyloglucans were determined by 13C-n.m.r. spectroscopy. 6. The structural features of the cell-wall polymers and complexes are discussed in relation to the structure of the cell walls of parenchyma tissues.


1980 ◽  
Vol 191 (2) ◽  
pp. 305-318 ◽  
Author(s):  
M R Lifely ◽  
E Tarelli ◽  
J Baddiley

The teichuronic acid of Bacillus licheniformis A.T.C.C. 9945 grown under phosphate limitation was isolated from the cell walls and purified by ion-exchange and Sephadex chromatography. The detailed structure of the polysaccharide was established by methylation analysis, periodate oxidation and partial acid hydrolysis. The polymer is composed of tetrasaccharide repeating units with the structure [GlcA beta(1 leads to 4)GlcA beta(1 leads to 3)GalNAc beta(1 leads to 6)GalNAc alpha(1 leads to 4)n. 13C n.m.r. analysis has confirmed most of the structural features of the polysaccharide and, in particular, the anomeric configurations and linkage positions of substituents. The teichuronic acid from glucose-limited cells was identical with that from cells grown under phosphate limitation.


1970 ◽  
Vol 25 (11) ◽  
pp. 1294-1301 ◽  
Author(s):  
Dieter Koch ◽  
Karl Heinz Schleifer ◽  
Otto Kandler

Cell walls of Bifidobacterium bifidum var. pennsylvanicus were isolated. The polysaccharide consisted of glucose, galactose and rhamnose. Teichoic acid was not present. The murein (peptidoglycan) contained MurNAc, GlcNH2NAc, ᴅ-Glu, Ala. ʟ-Ser, ᴅ-Asp and L-Orn in a ratio of about 1 : 1 : 1 : 2 : 1 : 1 : 1. In one batch a high amount of ʟ-glutamic acid was found. It was not a constituent of the murein since it remained in the lysozyme insensitive residue.The amino acid sequence of the murein was determined by analyzing the oligopeptides arising during partial acid hydrolysis. It was shown that the peptide subunits attached to the muramic acid are the same as in many other mureins: ʟ-Ala-ᴅ-Glu-ʟ-Orn-D-Ala. The interpeptide bridge consisted of β-ᴅ-aspartyl-ʟ-serine. Since about 35% of aspartic acid and 6% of ornithine are N-terminal in the cell wall, it was assumed that only 60% of the peptide subunits are cross-linked. 4 other strains of B. bifidum proved to contain the same type of murein. While all other strains of other species of Bifidobacterium investigated contained other types of murein, it seems likely that the Orn-Ser-Asp type of the murein is typical of B. bifidum.


2019 ◽  
Vol 26 (35) ◽  
pp. 6399-6411 ◽  
Author(s):  
Cláudia Nunes ◽  
Manuel A. Coimbra

Marine environments have a high quantity and diversity of sulfated polysaccharides. In coastal regions brown algae are the most abundant biomass producers and their cell walls have fucosecontaining sulfated polysaccharides (FCSP), known as fucans and/or fucoidans. These sulfated compounds have been widely researched for their biomedical properties, namely the immunomodulatory, haemostasis, pathogen inhibition, anti-inflammatory capacity, and antitumoral. These activities are probably due to their ability to mimic the carbohydrate moieties of mammalian glycosaminoglycans. Therefore, the FCSP are interesting compounds for application in health-related subjects, mainly for developing scaffolds for delivery systems or tissue regeneration. FCSP showed potential for these applications also due to their ability to form stable 3D structures with other polymers able to entrap therapeutic agents or cell and growth factors, besides their biocompatibility and biodegradability. However, for the clinical use of these biopolymers well-defined reproducible molecules are required in order to accurately establish relationships between structural features and human health applications.


1983 ◽  
Vol 34 (3) ◽  
pp. 241 ◽  
Author(s):  
CW Ford

Stem cell walls of pangola grass (Digitaria decumbens) were ground to two particle sizes (c. 1 and 0.1 mm diameter), and incubated with cellulase (ex. Trichoderma viride) for varying times before and after delignification. Total cell walls finely ground (0.1 mm) with a Spex Shatterbox mill were initially degraded more rapidly (to 24 h) than delignified 1 mm particles. Thereafter the delignified material was solubilized to a greater extent. Subsequent specific determinations of cell wall polysaccharides indicated that delignification increased the rate of hemicellulose degradation to a greater extent than did particle size reduction, whereas the opposite was found for cellulose. The difference between delignified and Spex-ground residues, in terms of the amount of polysaccharide digested, was much greater for cellulose than hemicellulose. It is concluded that structural features play a more important role in limiting cellulase degradation of cellulose than does association with lignin, the reverse being so for hemicellulose.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
So Young Park ◽  
Jieun Kim ◽  
Jung Il Son ◽  
Sang Youl Rhee ◽  
Do-Yeon Kim ◽  
...  

AbstractThe screening rate of diabetic retinopathy (DR) is low despite the importance of early diagnosis. We investigated the predictive value of dietary glutamic acid and aspartic acid for diagnosis of DR using the Korea National Diabetes Program cohort study. The 2067 patients with type 2 diabetes without DR were included. The baseline intakes of energy, glutamic acid and aspartic acid were assessed using a 3-day food records. The risk of DR incidence based on intake of glutamic acid and aspartic acid was analyzed. The DR group was older, and had higher HbA1c, longer DM duration, lower education level and income than non-DR group (all p < 0.05). The intake of total energy, glutamic acid and aspartic acid were lower in DR group than non-DR group (p = 0.010, p = 0.025 and p = 0.042, respectively). There was no difference in the risk of developing DR according to the intake of glutamic acid and ascorbic acid. But, aspartic acid intake had a negative correlation with PDR. Hence, the intake of glutamic acid and aspartic acid did not affect in DR incidence. However, lower aspartic acid intake affected the PDR incidence.


1964 ◽  
Vol 119 (6) ◽  
pp. 997-1004 ◽  
Author(s):  
Stephen N. Curtis ◽  
Richard M. Krause

Group G hemolytic streptococcal cell walls which have been treated with trypsin are composed of a group-specific polysaccharide moiety and a mucopeptide matrix. The mucopeptide contains N-acetylglucosamine, N-acetylmuramic acid, alanine, glutamic acid, lysine, and glycine, a composition similar to that of other groups of streptococci. The Group G carbohydrate is composed of rhamnose, N-acetylgalactosamine, and galactose. Serological studies suggest that the monosaccharide of L-rhamnose is a major component of the determinant of antigenic specificity.


Biopolymers ◽  
1990 ◽  
Vol 29 (3) ◽  
pp. 549-557 ◽  
Author(s):  
Toshio Hayashi ◽  
Makoto Iwatsuki
Keyword(s):  

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