scholarly journals Constant and variable domains of different disaccharide structure in corneal keratan sulphate chains

1987 ◽  
Vol 248 (1) ◽  
pp. 85-93 ◽  
Author(s):  
M Oeben ◽  
R Keller ◽  
H W Stuhlsatz ◽  
H Greiling
Keyword(s):  
Sugar Content ◽  
Kinetic Studies ◽  
Amino Sugar ◽  
Neuraminic Acid ◽  
Neutral Sugar ◽  
Keratan Sulphate ◽  
Mannose Residue ◽  
Linkage Region ◽  
Variable Domains ◽  
Kinetic Investigations

Four peptidokeratan sulphate fractions of different Mr and degree of sulphation were cut from the pig corneal keratan sulphate distribution spectrum. After exhaustive digestion with keratanase, the fragments were separated on DEAE-Sephacel and Bio-Gel P-10 and analysed for their Mr, degree of sulphation and amino sugar and neutral sugar content. It was found that every glycosaminoglycan chain is constructed of a constant domain of non-sulphated and monosulphated disaccharide units and a variable domain of disulphated disaccharide units. Total neuraminic acid of the four peptidokeratan sulphates was recovered from their isolated linkage-region oligosaccharides. In kinetic studies, the four peptidokeratan sulphates were investigated for Mr distribution after various incubation times with keratanase. There was a continuous shift towards lower Mr and no appearance of a distinct intermediate-sized product at any degradation time. The linkage-region oligosaccharide was already being liberated after a very short incubation period. From the results of these kinetic investigations in connection with the results of neuraminic acid analyses it is suggested that there exists only one disaccharide chain per peptidokeratan sulphate molecule. A model of corneal keratan sulphate is postulated. One of the alpha-mannose residues in the linkage region is bound to an oligosaccharide consisting of a lactosamine and a terminal sialic acid. The other alpha-mannose residue is attached to the disaccharide chain. This chain contains one or two non-sulphated disaccharide units at the reducing end, followed by 10-12 monosulphated disaccharide units. The disulphated disaccharide moiety of variable length is positioned at the non-reducing end of the chain.

scholarly journals The nature of the protein moieties of cartilage proteoglycans of pig and ox

1975 ◽  
Vol 149 (3) ◽  
pp. 657-668 ◽  
Author(s):  
E Baxter ◽  
H Muir
Keyword(s):  
Amino Acid ◽  
Chondroitin Sulphate ◽  
Gradient Centrifugation ◽  
Amino Sugar ◽  
Neutral Sugar ◽  
Hydrodynamic Size ◽  
Keratan Sulphate ◽  
Peptide Bonds ◽  
Core Proteins ◽  
Cartilage Proteoglycans

Proteoglycans extracted with 4M-guanidinium chloride from pig laryngeal cartilage and bovine nasal septum were purified by density-gradient centrifugation in CsCl under ‘associative’ followed by ‘dissociative’ conditions [Hascall & Sajdera (1969) J. Biol. Chem.244, 2384-2396]. Proteoglycans were then digested exhaustively with testicular hyaluronidase, which removed about 80% of the chondroitin sulphate. The hyaluronidase was purified until no proteolytic activity was detectable under the conditions used for digestion. The resulting ‘core’ proteins of both species were fractionated by a sequence of gel-chromatographic procedures which gave four major fractions of decreasing hydrodynamic size. Those that on electrophoresis penetrated 5.6% (w/v) polyacrylamide gels migrated as discrete bands whose mobility increased with decreasing hydrodynamic size. The unfractionated ‘core’ proteins had the same N-terminal amino acids as the intact proteoglycan, suggesting that no peptide bonds had been cleaved during hyaluronidase digestion. Alanine predominated as the N-terminal residue in all the fractions of both species. Fractions were analysed for amino acid, amino sugar, uronic acid and neutral sugar compositions. In pig ‘core’ proteins, the glutamic acid content increased significantly with hydrodynamic size, but in bovine ‘core’ proteins this trend was less marked. Significant differences in amino acid composition between fractions suggested that in each species there was more than one variety of proteoglycan. The molar proportions of xylose to serine destroyed on alkaline β-elimination were equivalent in most fractions, indicating that the serine residues destroyed were attached to the terminal xylose of chondroitin sulphate chains. The ratio of serine residues to threonine residues destroyed on β-elimination, was similar in all fractions of both species. Since the fractions of smallest hydrodynamic size contained less keratan sulphate than those of larger size, it implies that in the former the keratan sulphate chains were shorter than in the latter.

scholarly journals Resolution, purification and some properties of the multiple forms of cellobiose quinone dehydrogenase from the white-rot fungus Sporotrichum pulverulentum

1986 ◽  
Vol 236 (1) ◽  
pp. 221-226 ◽  
Author(s):  
F F Morpeth ◽  
G D Jones
Keyword(s):  
Superoxide Anion ◽  
Sugar Content ◽  
White Rot ◽  
Sedimentation Equilibrium ◽  
White Rot Fungus ◽  
Neutral Sugar ◽  
Apparent Difference ◽  
Multiple Forms ◽  
Sporotrichum Pulverulentum ◽  
Similar Kinetic

Four forms of cellobiose quinone dehydrogenase have been purified from the white-rot fungus Sporotrichum pulverulentum. The Mr of the enzyme has been estimated by sedimentation equilibrium to be 57,800 and by SDS/polyacrylamide-gel to be 60,000. These enzymes are clearly monomers. Cellobiose quinone dehydrogenases contain FAD and variable amounts of a green chromophore which we suggest is 6-hydroxy-FAD. The superoxide anion and H2O2 are the products of its reaction with oxygen. All of the isoenzymes from any one preparation display similar kinetic parameters. However, these vary between preparations. The only apparent difference between the four separable isoenzymes is their neutral-sugar content.

Effects of wall inhibitors on thymineless Streptococcus faecalis

1974 ◽  
Vol 20 (8) ◽  
pp. 1185-1187 ◽  
Author(s):  
J. G. Bisaillon ◽  
J. de Repentigny ◽  
L. G. Mathieu
Keyword(s):  
Free Amino ◽  
Death Rate ◽  
Sugar Content ◽  
Amino Sugar ◽  
Streptococcus Faecalis ◽  
Inhibition Of Growth ◽  
Thymineless Death

Thymine-requiring (thy−) mutants of Streptococcus faecalis and S. faecalis var. zymogenes were isolated by selection with aminopterin. D-Cycloserine increased the thymineless death rate of a S. faecalis thy− strain, whereas bacitracin, penicillin, and vancomycin decreased it. A S. faecalis var. zymogenes thy− strain behaved similarly, except that penicillin increased its thymineless death rate. D-Alanine reversed the effect of D-cycloserine on both strains. Because of the specificity of the inhibition, our observations suggest that mucopeptide synthesis occurs in S. faecalis not only during growth but also during thymineless death. The variations in free amino sugar content resulting from D-cycloserine inhibition of growth and thymineless death also support this conclusion.

THE MUCOPOLYSACCHARIDES OF HUMAN SKIN

1949 ◽  
Vol 27e (1) ◽  
pp. 43-57 ◽  
Author(s):  
R. H. Pearce ◽  
E. M. Watson
Keyword(s):  
Hyaluronic Acid ◽  
Sulphuric Acid ◽  
Human Skin ◽  
Sugar Content ◽  
Amino Sugar ◽  
Acid Fraction ◽  
Fresh Tissue ◽  
Mean Values ◽  
Technical Errors ◽  
Reducing Substances

The mean values and standard deviations for the concentrations of the hyaluronic acid and chondroitin sulphuric acid fractions isolated from 11 specimens of human skin were 24.5 ± 5.7 and 26.2 ± 4.7 mgm. per 100 gm. of fresh tissue, respectively.The individual differences in the concentrations of these substances were masked by the technical errors. The small variations in moisture and ash content of the skin did not contribute appreciably to the uncertainty of the concentration values. The purity of the products, determined by their amino sugar content, approximated 60%, which value compared favorably with those obtained by other workers.The content of hexosamine and uronic acid identified both fractions as acid mucopolysaccharides. The release of reducing substances, including N-acetyl hexosamine, from the hyaluronic acid fraction by hyaluronidase paralleled the action of the enzyme upon hyaluronate from umbilical cord. The chondroitin sulphuric acid fraction, which was relatively resistant to the action of hyaluronidase, was assumed to be identical with the chondroitin sulphatelike substance that Meyer and Chaffee isolated from pig skin.

THE INVERTASE OF THE CORN RADICLE AND ITS ACTIVITY IN SUCCESSIVE STAGES OF GROWTH

1962 ◽  
Vol 40 (1) ◽  
pp. 113-126 ◽  
Author(s):  
J. A. Hellebust ◽  
D. F. Forward
Keyword(s):  
Reducing Sugars ◽  
Sugar Content ◽  
Kinetic Studies ◽  
Invertase Activity ◽  
Cell Number ◽  
Permeability Barrier ◽  
Ph Optimum ◽  
Intact Cells ◽  
Stages Of Growth ◽  
Growing Cell

Segments of the first 10 millimeters of corn radicle tips have been analyzed in terms of invertase activity, cell number, fresh and dry weights, and sugar content. Invertase activity per cell increased 40-fold as the meristematic cell advanced to the stage of most rapid elongation, and again subsided as the cell ceased to elongate and entered the stage of maturation. In the growing cell, the concentration of sucrose remained low while that of reducing sugars increased fivefold.The corn radicle invertase was found to be a β-fructofuranosidase with a Km of 0.006 M and a pH optimum of 4.6. Kinetic studies indicate that there is no change in the nature of the corn radicle invertase during cell growth. Equivalent activities of intact cells or segments and homogenates is consistent with the assumption that the enzyme is located outside the permeability barrier of the cells.

scholarly journals Kinetic studies on the acid hydrolysis of the methyl ketoside of unsubstituted and O-acetylated N-acetylneuraminic acid

1973 ◽  
Vol 133 (4) ◽  
pp. 623-628 ◽  
Author(s):  
A. Neuberger ◽  
Wendy A. Ratcliffe
Keyword(s):  
Sialic Acid ◽  
Acid Hydrolysis ◽  
Model Compound ◽  
Kinetic Studies ◽  
Order Rate Constant ◽  
Neuraminic Acid ◽  
Acetylneuraminic Acid ◽  
Rate Of Hydrolysis ◽  
Ph Range ◽  
Hydrolysis Of

The hydrolysis of the model compound 2-O-methyl-4,7,8,9-tetra-O-acetyl-N-acetyl-α-d-neuraminic acid and neuraminidase (Vibrio cholerae) closely resembled that of the O-acetylated sialic acid residues of rabbit Tamm–Horsfall glycoprotein. This confirmed that O-acetylation was responsible for the unusually slow rate of acid hydrolysis of O-acetylated sialic acid residues observed in rabbit Tamm–Horsfall glycoprotein and their resistance to hydrolysis by neuraminidase. The first-order rate constant of hydrolysis of 2-methyl-N-acetyl-α-d-neuraminic acid by 0.05m-H2SO4 was 56-fold greater than that of 2-O-methyl-4,7,8,9-tetra-O-acetyl-N-acetyl -α-d-neuraminic acid. Kinetic studies have shown that in the pH range 1.00–3.30, the observed rate of hydrolysis of 2-methyl-N-acetyl-α-d-neuraminic acid can be attributed to acid-catalysed hydrolysis of the negatively charged CO2− form of the methyl ketoside.

Identification of genes differentially expressed in a strain of the moldAspergillus nidulanscarrying a loss-of-function mutation in thepalAgene

2008 ◽  
Vol 54 (10) ◽  
pp. 803-811 ◽  
Author(s):  
Emiliana M. Silva ◽  
Janaína S. Freitas ◽  
Diana E. Gras ◽  
Fábio M. Squina ◽  
Juliana Leal ◽  
...  
Keyword(s):  
Signal Transduction ◽  
Stress Responses ◽  
Genome Stability ◽  
Sugar Content ◽  
Signal Transduction Pathway ◽  
Subtractive Hybridization ◽  
Differentially Expressed ◽  
Neutral Sugar ◽  
Loss Of Function ◽  
Secretion Signal

To identify genes differentially expressed in a strain of the mold Aspergillus nidulans carrying a loss-of-function mutation in palA, a gene in the pH-responsive signal transduction pathway, suppression subtractive hybridization was performed between RNA isolated from the biA1 and biA1 palA1 strains grown under limiting inorganic phosphate at pH 5.0. We have identified several genes upregulated in the biA1 palA1 mutant strain that play important roles in mitotic fidelity, stress responses, enzyme secretion, signal transduction mechanisms, development, genome stability, phosphate sensing, and transcriptional regulation among others. The upregulation of eight of these transcripts was also validated by Northern blot. Moreover, we show that a loss of function mutation in the palA gene drastically reduced the neutral sugar content of the acid phosphatase PacA secreted by the fungus A. nidulans grown at pH 5.0 compared with a control strain.

scholarly journals There are two major types of skeletal keratan sulphates

1990 ◽  
Vol 271 (1) ◽  
pp. 243-245 ◽  
Author(s):  
I A Nieduszynski ◽  
T N Huckerby ◽  
J M Dickenson ◽  
G M Brown ◽  
G H Tai ◽  
...  
Keyword(s):  
Intervertebral Disc ◽  
Nasal Septum ◽  
High Field ◽  
Structural Features ◽  
Spectroscopic Studies ◽  
Neuraminic Acid ◽  
Keratan Sulphate

High-field 1H-n.m.r.-spectroscopic studies supported by chemical carbohydrate analyses show that skeletal keratan sulphates (KS-II) of bovine origin may be sub-classified into two groups. Keratan sulphate chains from articular and intervertebral-disc cartilage (KS-II-A) contain two structural features, namely alpha(1----3)-fucose and alpha(2----6)-linked N-acetyl-neuraminic acid residues, that are absent from keratan sulphates from tracheal or nasal-septum cartilage (KS-II-B).

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