CONSTITUTION OF AN EXTRACELLULAR ACIDIC GLUCOMANNAN FROM SERRATIA MARCESCENS

1965 ◽  
Vol 43 (11) ◽  
pp. 2940-2946 ◽  
Author(s):  
G. A. Adams ◽  
Robert Young

An acidic glucomannan isolated from culture filtrate of Serratia marcescens contained D-glucose and D-mannose (3.5:1), D-glucuronic acid (5.5%), and "bound" fatty acids (7.4%). The polysaccharide, on examination by moving boundary electrophoresis and by sedimentation in the ultracentrifuge, was homogeneous. Degree of polymerization was estimated to be ca. 20 by vapor pressure osmometry. Isolation of nigerose (3-O-α-D-glucopyranosyl-D-glucopyranose) established the glycosidic linkage between the D-glucose units as α (1 → 3). Methylation and periodate oxidation data showed that the D-glucose and D-mannose units were joined by (1 → 3) linkages in a straight chain structure terminated at the non-reducing end by a unit of D-glucuronic acid which was attached to C3 of a D-mannose residue. The reducing end of the molecule was terminated by a D-glucose unit. The fatty acids, consisting mainly of hydroxymyristic acid and myristic acid, were attached to the molecule mainly by ester linkages.

1962 ◽  
Vol 40 (2) ◽  
pp. 348-352 ◽  
Author(s):  
G. G. S. Dutton ◽  
A. M. Unrau

By determining the amount of formaldehyde produced on periodate oxidation of borohydride-reduced apple- and cherry-wood xylans the degree of polymerization was shown to be 155 and 100 respectively. Acid hydrolysis of the polyols obtained by periodate oxidation and borohydride reduction gave ethylene glycol in amounts indicating that these xylans have a small degree of branching. Mild acid hydrolysis of the polyols demonstrated that in these xylans D-glucuronic acid as well as 4-O-methyl-D-glucuronic acid was present and that some of the former occupied non-terminal positions.


1954 ◽  
Vol 32 (2) ◽  
pp. 186-194 ◽  
Author(s):  
G. A. Adams

Crude hemicellulose of mature wheat leaves has been prepared by alkaline extraction of leaf holocellulose. Purification by repeated complexing with Fehling′s solution yielded a polyuronide hemicellulose [Formula: see text] composed of D-xylose (88.5%), L-arabinose (6.90%), and uronic acid anhydride (5.27%). Methylation studies indicated a molecular structure comprising a main xylan chain of 30 an-hydro- D-xylose residues to which three L-arabinose residues and one D-glucuronic acid unit were attached as side chains by glycosidic linkages. Periodate oxidation data supported the proposed structure and the yield of formic acid indicated a molecule containing approximately 32 sugar residues. Estimations of the degree of polymerization of the molecule by measurements of viscosity and reducing power agreed with the foregoing values. The structure of the hemicellulose closely resembled that of one isolated previously from wheat straw.


1960 ◽  
Vol 38 (12) ◽  
pp. 2402-2409 ◽  
Author(s):  
G. A. Adams

An acidic xylan isolated from tamarack wood contained arabinose, xylose, and uronic acid (1:17:3) and was homogeneous on examination by electrophoresis and sedimentation. Molecular weight estimations by four different methods showed a degree of polymerization of 20. Methylation and periodate oxidation showed that the xylan consisted of ca. 16 β-D-xylopyranose units joined by 1 → 4 glycosidic bonds with the possible occurrence of one 1 → 3 linkage. To this unbranched structure were attached as side branches, three single units of 4-O-methyl-D-glucuronic acid through C2 and one unit of L-arabofuranose through C3.


Microbiology ◽  
2011 ◽  
Vol 157 (6) ◽  
pp. 1589-1601 ◽  
Author(s):  
Yoshihiro Agari ◽  
Kazuko Agari ◽  
Keiko Sakamoto ◽  
Seiki Kuramitsu ◽  
Akeo Shinkai

In the extremely thermophilic bacterium Thermus thermophilus HB8, one of the four TetR-family transcriptional regulators, which we named T. thermophilus FadR, negatively regulated the expression of several genes, including those involved in fatty acid degradation, both in vivo and in vitro. T. thermophilus FadR repressed the expression of the target genes by binding pseudopalindromic sequences covering the predicted −10 hexamers of their promoters, and medium-to-long straight-chain (C10–18) fatty acyl-CoA molecules were effective for transcriptional derepression. An X-ray crystal structure analysis revealed that T. thermophilus FadR bound one lauroyl (C12)-CoA molecule per FadR monomer, with its acyl chain moiety in the centre of the FadR molecule, enclosed within a tunnel-like substrate-binding pocket surrounded by hydrophobic residues, and the CoA moiety interacting with basic residues on the protein surface. The growth of T. thermophilus HB8, with palmitic acid as the sole carbon source, increased the expression of FadR-regulated genes. These results indicate that in T. thermophilus HB8, medium-to-long straight-chain fatty acids can be used for metabolic energy under the control of FadR, although the major fatty acids found in this strain are iso- and anteiso-branched-chain (C15 and 17) fatty acids.


1980 ◽  
Vol 191 (1) ◽  
pp. 103-110 ◽  
Author(s):  
Ingrid Sjöberg ◽  
Lars-Ȧke Fransson

1. 3H- and 35S-labelled heparan sulphate was isolated from monolayers of human lung fibroblasts and subjected to degradations by (a) deaminative cleavage and (b) periodate oxidation/alkaline elimination. Fragments were resolved by gel- and ion-exchange-chromatography. 2. Deaminative cleavage of the radioactive glycan afforded mainly disaccharides with a low content of ester-sulphate and free sulphate, indicating that a large part (approx. 80%) of the repeating units consisted of uronosyl-glucosamine-N-sulphate. Blocks of non-sulphated [glucuronosyl-N-acetyl glucosamine] repeats (3–4 consecutive units) accounted for the remainder of the chains. 3. By selective oxidation of glucuronic acid residues associated with N-acetylglucosamine, followed by scission in alkali, the radioactive glycan was degraded into a series of fragments. The glucuronosyl-N-acetylglucosamine-containing block regions yielded a compound N-acetylglucosamine–R, where R is the remnant of an oxidized and degraded glucuronic acid. Periodate-insensitive uronic acid residues were recovered in saccharides of the general structure glucosamine–(uronic acid–glucosamine)n–R. 4. Further degradations of these saccharides via deaminative cleavage and re-oxidations with periodate revealed that iduronic acid may be located in sequences such as glucosamine-N-sulphate→iduronic acid→N-acetylglucosamine. Occasionally the iduronic acid was sulphated. Blocks of iduronic acid-containing repeats may contain up to five consecutive units. Alternating arrangements of iduronic acid- and glucuronic acid-containing repeats were also observed. 5. 3H- and 35S-labelled heparan sulphates from sequential extracts of fibroblasts (medium, EDTA, trypsin digest, dithiothreitol extract, cell-soluble and cell-insoluble material) afforded similar profiles after both periodate oxidation/alkaline elimination and deaminative cleavage.


1962 ◽  
Vol 40 (12) ◽  
pp. 2204-2213 ◽  
Author(s):  
A. Misaki ◽  
S. Kirkwood ◽  
J. V. Scaletti ◽  
F. Smith

The extracellular polysaccharide isolated from cultures of Xanthomonas oryzae is composed of D-glucose (5 molecular proportions), D-glucuronic acid (2 molecular proportions), and D-mannose (5 molecular proportions). Acid hydrolysis of this polysaccharide, which contains 0.3% combined pyruvic acid, yields 2-O-β-D-glucopyranosyluronic acid D-mannose, which has been characterized as its crystalline fully methylated β-glycoside. Hydrolysis of the methylated polysaccharide gives 2,3,4,6-tetra-O-methyl-D-mannose (3 molecular proportions), 2,3,4-tri-O-methyl-D-glucuronic acid (1 molecular proportion), 2,3,6-tri-O-methyl-D-glucose (4 molecular proportions), 3,4,6-tri-O-methyl-D-mannose (2 molecular proportions), 2,6-di-O-methyl-D-glucose (3 molecular proportions), 2,3-di-O-methyl-D-glucose (1 molecular proportion). The polyalcohol derived from the polysaccharide by periodate oxidation followed by sodium borohydride reduction gives upon acid hydrolysis glycerol (2 molecular proportions), erythritol (1 molecular proportion), and D-glucose (1 molecular proportion). The general structural significance of these findings is discussed.


1955 ◽  
Vol 9 ◽  
pp. 864-865 ◽  
Author(s):  
Olavi Perilä ◽  
Rolf Gmelin ◽  
Ivan Larsen ◽  
Ole Lamm

2005 ◽  
Vol 55 (6) ◽  
pp. 2519-2523 ◽  
Author(s):  
Yoon-Dong Park ◽  
Keun Sik Baik ◽  
Hana Yi ◽  
Kyung Sook Bae ◽  
Jongsik Chun

A Gram-negative, motile, strictly aerobic, violet-pigment-producing bacterium, designated strain FR1199T, was isolated from tidal flat sediment of Byunsan, South Korea. Phylogenetic analysis of the 16S rRNA gene sequence revealed that strain FR1199T represents a distinct line of descent within the genus Pseudoalteromonas. The phenotypic features of strain FR1199T were similar to those of Pseudoalteromonas phenolica and Pseudoalteromonas luteoviolacea, but several physiological and chemotaxonomical properties readily distinguished strain FR1199T from these species. Major fatty acids were straight-chain saturated (C16 : 0) and monounsaturated C18 : 1 ω7c fatty acids. The DNA G+C content was 39 mol%. On the basis of polyphasic evidence, it is concluded that the isolate represents a novel species within the genus Pseudoalteromonas, for which the name Pseudoalteromonas byunsanensis sp. nov. is proposed. The type strain is FR1199T (=JCM 12483T=KCTC 12274T).


1966 ◽  
Vol 44 (11) ◽  
pp. 1275-1282 ◽  
Author(s):  
V. Zitko ◽  
C. T. Bishop

Fractions of sunflower pectic acid containing 89.8%, 94.2%, and 91.4% of D-galacturonic acid were carboxyl reduced as their methyl or ethylene glycol esters by potassium borohydride. Critical assessment of the effects of three different solvents (water, 80% aqueous dimethyl sulfoxide, and 80% aqueous methanol) on the efficiency of reduction showed that the latter solvent was best. The reductions caused a decrease in the degree of polymerization from 270 to 21. Measurement of the rates of hydrolysis of partially reduced pectic acids containing 90%, 41.6%, 19.9%, 11.0%, and 0.65% of D-galacturonic acid showed that the rate of hydrolysis was directly related to the proportion of galacturonosidic linkages present. Methylation and hydrolysis of the carboxyl-reduced pectic acid fractions yielded 2,3,4,6-tetra-O-methyl-D-galactose and 2,3,6-tri-O-methyl-D-galactose in an approximate molar ratio of 1:20. Results of the periodate oxidation of the carboxyl-reduced pectic acid supported the conclusion inferred from the methylation results that the pectic acid was a linear polymer of 1 → 4 linked α-D-galacturonic acid units.


1975 ◽  
Vol 152 (2) ◽  
pp. 191-199 ◽  
Author(s):  
Gerard J. A. Oliver ◽  
Frank W. Hemming

The transfer, catalysed by pig liver microsomal preparations, of mannose, from GDP-mannose, to lipid-linked oligosaccharides and the properties of the products are described. Solubility, hydrolytic and chromatographic data suggest that they are dolichol diphosphate derivatives. The presence of two N-acetyl groups in at least part of the heterogenous oligosaccharide portion was tentatively deduced. Reduction with borohydride of the oligosaccharide showed that the newly added mannose residues were not at its reducing end. Periodate oxidation suggested that 60% of these were at the non-reducing terminus and that 40% were positioned internally. T.l.c. showed the presence of seven oligosaccharide fractions with chromatographic mobilities corresponding to glucose oligomers with 7–13 residues. The molar proportions of the oligosaccharide fractions in the mixture were determined by borotritiide reduction and the number of mannose residues added to each oligosaccharide fraction during the incubation was calculated. Two of the oligosaccharide fractions had received on average one, or slightly more than one, mannose residue per chain during the incubation; four of the other fractions were each shown to be a mixture, 20–25% of which had received one mannose residue during the incubation and 75–80% of which had not been mannosylated during the incubation. This supported other evidence for the presence of endogenous lipid-linked oligosaccharides in the microsomal preparation which had been formed before the incubation in vitro. Evidence for the possibility of two pools of dolichol monophosphate mannose, one being more closely associated with mannosyl transfer to dolichol diphosphate oligosaccharides than the other, is also discussed.


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