scholarly journals TYPE AND GROUP POLYSACCHARIDES OF GROUP D STREPTOCOCCI

1960 ◽  
Vol 111 (5) ◽  
pp. 621-630 ◽  
Author(s):  
S. D. Elliott
Keyword(s):  
Cell Walls ◽  
Alkaline Treatment ◽  
Single Component ◽  
Comparable Amount ◽  
Mechanical Disruption ◽  
Specific Polysaccharide ◽  
Group D

Polysaccharides extracted from cell walls of 4 serological types of Group D streptococci were serologically type-specific. Acid hydrolysates of all 4 contained hexosamine (glucosamine), rhamnose and glucose. A polysaccharide extracted from 2 serological types by either alkaline treatment or mechanical disruption was serologically group-specific. Acid hydrolysates contained glucose and no other single component in comparable amount. The group-specific polysaccharide, which may be of a dextran-like nature, is probably situated wholly or in part at the surface of the streptococcus.

scholarly journals THE PRESENCE OF A GROUP A VARIANT-LIKE ANTIGEN IN STREPTOCOCCI OF OTHER GROUPS WITH SPECIAL REFERENCE TO GROUP N

1971 ◽  
Vol 133 (3) ◽  
pp. 479-493 ◽  
Author(s):  
S. D. Elliott ◽  
John Hayward ◽  
T. Y. Liu
Keyword(s):  
Cell Wall ◽  
Special Reference ◽  
Cell Walls ◽  
Cell Wall Structure ◽  
Wall Structure ◽  
Specific Polysaccharide ◽  
Group A ◽  
Unknown Composition ◽  
Group D ◽  
Serological Specificity

A Group A variant-like antigen has been detected in streptococci belonging to Groups D, E, G, M, and N. In Groups D and N the variant-like antigen was located in the streptococcal cell walls. In two strains of Group N streptococci (C559 and B209) the cell walls were chemically different and serologically distinct. In strain C559 N-acetylgalactosamine, and in strain B209, N-acetylglucosamine were the major determinants of serological specificity. The cell walls of strain C559 contained at least three serologically reactive components: a rhamnose-containing fraction that precipitated with an antiserum to Group A-variant carbohydrate; a strain-specific polysaccharide composed of galactosamine and glucosamine, both in the N-acetylated form and probably polymerized with an unidentified phosphorylated substance; and a component of unknown composition serologically related to a Group D streptococcus strain C3 (S. durans). An analogy is drawn between the cell wall structure in streptococcus and Salmonella.

scholarly journals IMMUNOCHEMICAL STUDIES ON THE SPECIFIC CARBOHYDRATE OF GROUP G STREPTOCOCCI

1964 ◽  
Vol 119 (6) ◽  
pp. 997-1004 ◽  
Author(s):  
Stephen N. Curtis ◽  
Richard M. Krause
Keyword(s):  
Glutamic Acid ◽  
Cell Walls ◽  
Antigenic Specificity ◽  
Group G Streptococci ◽  
Serological Studies ◽  
Specific Polysaccharide

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.

Cell Walls of Group D Streptococci II. Chemical Studies on the Type 1 Antigen Purified from the Autolytic Digest of Cell Walls

1967 ◽  
Vol 94 (5) ◽  
pp. 1381-1387 ◽  
Author(s):  
Arnold S. Bleiweis ◽  
Frank E. Young ◽  
Richard M. Krause
Keyword(s):  
Cell Walls ◽  
Chemical Studies ◽  
Group D

Glycans from streptococcal cell walls: Glycosyl-phosphoryl moieties as immunodominant groups in heteroglycans from group D and group L Streptococci

1971 ◽  
Vol 43 (6) ◽  
pp. 1421-1428 ◽  
Author(s):  
John H. Pazur ◽  
Austra Cepure ◽  
Judith A. Kane ◽  
Walter W. Karakawa
Keyword(s):  
Cell Walls ◽  
Group D

Chemical composition of cell walls of Saccharomyces fragilis

1969 ◽  
Vol 15 (9) ◽  
pp. 989-993 ◽  
Author(s):  
T. Reuvers ◽  
E. Tacoronte ◽  
C. Garcia Mendoza ◽  
M. Novaes-Ledieu
Keyword(s):  
Amino Acids ◽  
Chemical Composition ◽  
Cell Walls ◽  
Carbohydrate Content ◽  
Positive Component ◽  
High Carbohydrate ◽  
Mechanical Disruption

Cell walls of Saccharomyces fragilis grown in two different media were prepared by mechanical disruption, and their chemical composition was studied. A high carbohydrate content (75–80%) was found in these walls. Glucose and mannose were represented in a ratio 1:1 in both cases; cell walls also contained a small amount of glucosamine. Sixteen common amino acids were detected in S. fragilis wall hydrolysates. One unidentified ninhydrin-positive component was present when the organism was grown in Hansen medium. A low percentage of lipid was found in both walls. The significance of all these data is discussed in the light of the difficulties encountered in the preparation and purification of walls.

scholarly journals Tuning of pKa values activates substrates in flavin-dependent aromatic hydroxylases

2020 ◽  
Vol 295 (12) ◽  
pp. 3965-3981 ◽  
Author(s):  
Warintra Pitsawong ◽  
Pirom Chenprakhon ◽  
Taweesak Dhammaraj ◽  
Dheeradhach Medhanavyn ◽  
Jeerus Sucharitakul ◽  
...  
Keyword(s):  
Active Sites ◽  
Single Component ◽  
Electrophilic Aromatic Substitution ◽  
Aromatic Substitution ◽  
Substrate Analogs ◽  
Two Component ◽  
Group A ◽  
Catalytic Mechanisms ◽  
Protein Variants ◽  
Group D

Hydroxylation of substituted phenols by flavin-dependent monooxygenases is the first step of their biotransformation in various microorganisms. The reaction is thought to proceed via electrophilic aromatic substitution, catalyzed by enzymatic deprotonation of substrate, in single-component hydroxylases that use flavin as a cofactor (group A). However, two-component hydroxylases (group D), which use reduced flavin as a co-substrate, are less amenable to spectroscopic investigation. Herein, we employed 19F NMR in conjunction with fluorinated substrate analogs to directly measure pKa values and to monitor protein events in hydroxylase active sites. We found that the single-component monooxygenase 3-hydroxybenzoate 6-hydroxylase (3HB6H) depresses the pKa of the bound substrate analog 4-fluoro-3-hydroxybenzoate (4F3HB) by 1.6 pH units, consistent with previously proposed mechanisms. 19F NMR was applied anaerobically to the two-component monooxygenase 4-hydroxyphenylacetate 3-hydroxylase (HPAH), revealing depression of the pKa of 3-fluoro-4-hydroxyphenylacetate by 2.5 pH units upon binding to the C2 component of HPAH. 19F NMR also revealed a pKa of 8.7 ± 0.05 that we attributed to an active-site residue involved in deprotonating bound substrate, and assigned to His-120 based on studies of protein variants. Thus, in both types of hydroxylases, we confirmed that binding favors the phenolate form of substrate. The 9 and 14 kJ/mol magnitudes of the effects for 3HB6H and HPAH-C2, respectively, are consistent with pKa tuning by one or more H-bonding interactions. Our implementation of 19F NMR in anaerobic samples is applicable to other two-component flavin-dependent hydroxylases and promises to expand our understanding of their catalytic mechanisms.

scholarly journals The Spatial Orientation and Interaction of Cell Wall Polymers in Bamboo Revealed with a Combination of Imaging Polarized FTIR and Directional Chemical Removal

2021 ◽  
Author(s):  
Jiawei Zhu ◽  
Wenting Ren ◽  
Fei Guo ◽  
Hankun Wang ◽  
Yan Yu
Keyword(s):  
Cell Wall ◽  
Spatial Orientation ◽  
Cell Walls ◽  
Alkaline Treatment ◽  
Molecular Assembly ◽  
Mechanical And Physical Properties ◽  
Cell Wall Polymers ◽  
Parenchyma Cells ◽  
Bamboo Fibers ◽  
Polarized Ftir

Abstract The mechanical and physical properties of lignocellulosic materials are closely related to the orientation and interaction of the polymers within cell walls. In this work, Imaging Polarized FTIR, combined with directional chemical removal, was applied to characterize the spatial orientation and interaction of cell wall polymers in bamboo fibers and parenchyma cells from two bamboo species. The results demonstrate the cellulose in bamboo fibers is nearly axially oriented whereas it is almost transversely arranged in parenchyma cells. Xylan and lignin are both preferentially oriented alongside cellulose, but with less orientation degre in the parenchyma cells. After lignin removal, the average orientation of xylan and cellulose is little affected, suggesting a strong interaction between cellulose and xylan. Meanwhile, the alkaline treatment significantly weakens the orientation of lignin in both fibers and parenchyma cells, and more significant for the latter, indicating the easy-degradable nature of lignin in parenchyma cells. And, it seemed the lignin and xylan in fibers were more difficult to be removed as compared to parenchyma cells, supporting the assumption that stronger interaction exists between lignin and xylan in the fibers. In a word, it was believed parenchyma cells are more suitable for biorefinery owing to its less ordered and relatively loose molecular assembly, as compared to fibers.

scholarly journals Demonstraction and interpretation of the yeast lee ability to adsorb certain volatile thiols contained in wine

OENO One ◽  
1996 ◽  
Vol 30 (4) ◽  
pp. 201 ◽  
Author(s):  
Valérie Lavigne-Cruège ◽  
Denis Dubourdieu
Keyword(s):  
Yeast Cell ◽  
Adsorption Capacity ◽  
Cell Walls ◽  
Culture Medium ◽  
The Other ◽  
Beta Glucanase ◽  
Whole Cells ◽  
Mechanical Disruption ◽  
Disulphide Bonds ◽  
Volatile Thiols

<p style="text-align: justify;">Yeast lees isolated from wine or a culture medium after fermentation have the particular property of being able to adsorb certain volatile thiols contained in a hydroalcoholic wine-like solution. Yeast cell-walls are also able to adsorb the same thiols when prepared by mechanical disruption of whole cells in the presence of a reducing agent such as dithiothréitol (DTT). Thiols adsorbed in this manner may be re-released from the cell-walls by the addition of DTT in the medium. On the other hand, yeast cell-walls prepared under the same conditions lose their adsorption capacity following hydrolysis with a beta-glucanase preparation able to release mannoproteins.</p><p style="text-align: justify;">These results indicate that volatile thiols combine with the yeast cell-walls by means of disulphide bonds with the cystein contained in mannoproteins.</p>

Electron Microscopic Studies on Streptococci

1970 ◽  
Vol 28 ◽  
pp. 194-195
Author(s):  
JOHN SWANSON M.D.
Keyword(s):  
Cell Walls ◽  
Teichoic Acid ◽  
Chemical Components ◽  
Group A Streptococci ◽  
Electron Microscopic ◽  
Histochemical Methods ◽  
Specific Polysaccharide ◽  
Microscopic Studies ◽  
Group A ◽  
Comparative Examination

Group A streptococci contain a variety of chemical components in their cell walls. The major components are mucopeptide, group-specific polysaccharide, protein constituents (M,T, and R), and teichoic acid. Investigations have been carried out to determine the location of each of these classes of chemical components. The techniques used include simple, comparative examination of selected strains that lack or possess a particular component, electron histochemical methods, immunoferritin methods, and extraction or removal of a particular component.

Determination of anionic groups in wood by time-of-flight secondary ion mass spectrometry and laser ablation-inductively coupled plasma-mass spectrometry

Holzforschung ◽  
2010 ◽  
Vol 64 (1) ◽  
Author(s):  
Elena N. Tokareva ◽  
Andrey V. Pranovich ◽  
Paul Ek ◽  
Bjarne Holmbom
Keyword(s):  
Mass Spectrometry ◽  
Cell Walls ◽  
Inductively Coupled Plasma ◽  
Secondary Ion Mass Spectrometry ◽  
Alkaline Treatment ◽  
Inductively Coupled ◽  
Tof Sims ◽  
Icp Ms ◽  
Plasma Mass Spectrometry ◽  
Anionic Groups

Abstract A novel method for labelling of anionic groups on wood surfaces was developed and applied to spruce and aspen wood sections in the native state, and after acid washing and alkaline treatment. The metal ions Mg2+, Cu2+, Sr2+, and Zn2+ were used as markers and their patterns of attachment to anionic groups were assessed by time-of-flight secondary ion mass spectrometry (ToF-SIMS). Sr2+ was found to be a very suitable marker for labelling of anionic groups. In addition to ToF-SIMS, laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) was used for semi-quantitative analysis of labelled anionic groups in wood samples. ToF-SIMS imaging of Sr2+-labelled anionic groups revealed abundant anionic groups in bordered pit tori and ray parenchyma cell walls in spruce wood. LA-ICP-MS revealed that the relative concentration of Sr2+ in tori of bordered pits was approximately eight-fold higher than in fibre cell walls. After alkaline treatment the concentration of anionic groups in the fibre cell wall was approximately three-fold higher than in the original acid-washed spruce. In aspen wood, anionic groups were located mainly in pits between vessels and contact ray parenchyma cells, in ray cell walls and in certain fibre wall layers.

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