scholarly journals Structural analysis of the carbohydrate chains of β-N-acetylhexosaminidases from bovine brain

1985 ◽  
Vol 232 (3) ◽  
pp. 637-641 ◽  
Author(s):  
B Overdijk ◽  
E P Beem ◽  
G J van Steijn ◽  
L A Trippelvitz ◽  
J J Lisman ◽  
...  

The oligosaccharide structures of bovine brain beta-N-acetylhexosaminidases A and B (EC 3.2.1.30) were studied at the glycopeptide level by employing 500 MHz 1H-n.m.r. spectroscopy and methylation analysis involving g.l.c.-m.s. More than 90% of the chains were found to be of the oligomannoside type, containing, on average, five to six mannose residues. Biantennary N-acetyl-lactosamine-type chains terminated in N-acetylneuraminic acid were found to comprise the remaining 5-10% of the total carbohydrate. The isoenzyme forms A and B do not differ from each other in the structure of their carbohydrate moiety, but do deviate in carbohydrate content and, in consequence, in the number of carbohydrate chains per molecule.

1991 ◽  
Vol 277 (3) ◽  
pp. 753-758 ◽  
Author(s):  
H Watzlawick ◽  
M T Walsh ◽  
I Ehrhard ◽  
H S Slayter ◽  
H Haupt ◽  
...  

Galactoglycoprotein is a unique human plasma protein [76% carbohydrate (23% N-acetylneuraminic acid, 20% galactose, 3% mannose, 1% fucose and 29% N-acetylgalactosamine plus N-acetylglucosamine) and 24% polypeptide, a single polypeptide chain of about 200 amino acid residues that is high in serine and threonine content] [Schmid, Mao, Kimura, Hayashi & Binette (1980) J. Biol. Chem. 255, 3221-3226]. Highly purified exoglycosidases with well-defined specificities were used to prepare five derivatives of galactoglycoprotein in which sequential residues of N-acetylneuraminic acid, galactose, N-acetylglucosamine, a second galactose and N-acetylgalactosamine were removed with 83% of the total carbohydrate cleaved. C.d. shows that native galactoglycoprotein and all derivatives in aqueous buffer are predominantly random coil, suggesting that removal of a large number of electrostatic net charges, as well as the major portion of the carbohydrate moiety, does not alter the secondary structure of the polypeptide chain. Examination of the size and conformation of tungsten-shadowed galactoglycoprotein and asialo and agalacto derivatives by electron microscopy shows the size and conformation of all three preparations to be similar, with only minor differences in particle length and width.


2013 ◽  
Vol 41 (1) ◽  
pp. 255 ◽  
Author(s):  
Ercan YILDIZ ◽  
Mustafa KAPLANKIRAN ◽  
Turan Hakan DEMIRKESER ◽  
Celil TOPLU

The study was conducted at the experimental farm of Mustafa Kemal University, Dörtyol, Turkey during the 2010 and 2011 growing seasons. The aim of this study was to investigate the effect of ‘Troyer’ and ‘Carrizo’ citranges (Poncirus trifoliata Raf. × Citrus sinensis Osb. var. ‘Troyer’ and ‘Carrizo’), and common sour orange (Citrus aurantium L. var. common), rootstocks on the seasonal variation of carbohydrate content in the leaves of cvs. ‘Fremont’, ‘Nova’, and ‘Robinson’ mandarin. The seasonal variation of carbohydrate content of the three cultivars budded on different rootstocks was nearly same. Soluble carbohydrate concentration showed a continuous decrease from January to mid or late-summer, and then slowly began to increase after early autumn till winter. The sucrose was the dominant soluble carbohydrate in leaves. The seasonal evolution of starch content in leaves increased initially during January to March, and then decreased in April. The starch concentration showed a continuous decrease slowly until the mid-autumn, and then accumulation began during late-autumn and winter. The total carbohydrate content differences among the rootstocks were significant, but the content was changed among the cultivars and according to the season. The change in the total carbohydrate content of leaf tissues showed a strong similarity in cultivars budded on different rootstocks throughout the year. The total carbohydrate content reached their lowest levels in July for cv. ‘Robinson’, in August for cv. ‘Fremont’ and cv. ‘Nova’. The total carbohydrate content in leaves increased from the mid- or late-summer to winter. It is suggested that the seasonal variation of carbohydrate content in plant tissues can be considered during fertilization program in mandarin trees.


2018 ◽  
Vol 64 (No. 9) ◽  
pp. 379-386 ◽  
Author(s):  
Deligöz Ayşe ◽  
Bayar Esra ◽  
Genç Musa ◽  
Karatepe Yasin ◽  
Kirdar Erol ◽  
...  

Variations in the photosynthetic pigments and total carbohydrate contents of needles of different age classes (current-year, 1-year-old, 2-year-old and 3-year-old) of Pinus nigra subsp. pallasiana (Lambert) Holmboe trees in a young natural stand were investigated during the growing season. In current-year needles, total carbohydrate content was lower during June and July when the needle growth continued than in older age classes, but it was similar to other age classes in the months of August to October. Seasonal patterns of variations in total carbohydrate content were almost similar in 1-, 2-, and 3-year-old needles. Chlorophyll and carotenoid contents increased from May to June, remained relatively constant or declined slightly during summer and autumn in 1-, 2-, and 3-year-old needles. In October, the pigment content was highest in 1-year-old needles, and lowest in 3-year-old needles. Our study indicated that total carbohydrate and pigment contents were affected by needle age classes and seasons.


1977 ◽  
Vol 37 (1) ◽  
pp. 55-65 ◽  
Author(s):  
A. B. McAllan ◽  
R. H. Smith

1. Samples of rumen digesta were taken at different times after giving calves various dried forage or hay and cereal diets and mixed bacteria were separated.2. For calves receiving dried forage only, the carbohydrate content of mixed bacteria varied with time after feeding, reaching a maximum of approximately 140 g/kg dry matter (DM) after 0.5-1 h, decreasing to about 60 g/kg DM after 4 h.3. Replacement of part of the dried forage with glucose to give a similar metabolizable energy intake but approximately half as much nitrogen, produced a similar pattern of change with time after feeding but resulted in a markedly increased maximum bacterial carbohydrate content (approximately 230 g/kg DM). Addition of urea to this diet reduced the bacterial accumulation of carbohydrate to approximately the same level as was found in samples from calves receiving forage only diets. For the forage diets the carbohydrate content fell to 60-100 g/kg DM 4 h after feeding. For the hay and cereal diet the value was 170 g/kg DM at this time.4. Changes in bacterial carbohydrate content were largely a result of changes in storage polysaccharide (α-dextran) content.5. Crude protein (N × 6.25) and ash contents of mixed bacteria decreased after feeding with all-forage diets, but returned to approximately fasting levels within 4 h. At this time samples from calves receiving dried forage and glucose diets contained less CP and more ash (approximately 450 and 220 g/kg DM respectively) than those from calves given diets of dried forage only (approximately 525 and 180 g/kg DM respectively).6. CP, total carbohydrate and ash content of mixed rumen bacteria contributed approximately 0.80 g/g DM.7. Sodium, potassium, calcium, magnesium and phosphate accounted for approximately 0.50 g/g bacterial ash.


1982 ◽  
Vol 33 (3) ◽  
pp. 559 ◽  
Author(s):  
BT Steer

Onion bulbs (Allium cepa L. cv. Creamgold), grown in a phytotron from seed, had a dry weight as percentage of fresh weight that decreased as growth temperatures increased from 22/16 to 33/28�C day/night. There were no significant differences between growth temperatures in the fructose, sucrose or fructan content and, although glucose content was higher at high temperatures, there was no correlation of total carbohydrate content with growth temperature. The sum of fructose, glucose and sucrose per unit tissue water was constant between temperatures, suggesting that the mono- and disaccharide content may control the bulb water content. These results, from controlled-environment tests, predict that in the field the best yield of dry weight as a percentage of fresh weight will be obtained at low growth temperatures.


1973 ◽  
Vol 51 (3) ◽  
pp. 219-224 ◽  
Author(s):  
C. G. Fraser ◽  
H. J. Jennings ◽  
P. Moyna

An acidic polysaccharide has been isolated from the culture medium of T. mesenterica NRRL Y-6158. The heteropolymer contained D-xylose, D-mannose, D-glucuronic acid, and O-acetyl in the molar ratios of 7:5:1:0.7, respectively. Methylation analysis of the heteropolymer indicated that it was essentially a 1 → 3-α-linked mannopyranose backbone having approximately 80% of the backbone units substituted, thus forming a very highly branched structure. The substituents on the backbone were found to be D-glucopyranosyluronic acid end-group, β-linked to the O-2 positions of the mannopyranose units, and 2-O-β-D-linked xylopyranose side-chains, linked both to the O-2 and O-4 positions of the mannopyranose backbone. The methylation analysis suggests that these side-chains are probably two or three xylopyranose units long, although a limited variation in the length of the side-chains is a possibility.


1968 ◽  
Vol 107 (3) ◽  
pp. 341-352 ◽  
Author(s):  
G. Dawson ◽  
J. R. Clamp

The carbohydrate content of an A myeloma globulin was investigated. The carbohydrate content was found to be unchanged when the protein was isolated from the patient over a period of 18 months. The various polymeric forms of the protein contained similar proportions of carbohydrate. The A myeloma globulin contained approx. 2 residues of 6-deoxy-l-galactose (l-fucose), 14–15 of d-mannose, 12–13 of d-galactose, 12–13 of 2-acetamido-2-deoxy-d-glucose (N-acetyl-d-glucosamine), 6 of 2-acetamido-2-deoxy-d-galactose (N-acetyl-d-galactosamine) and 5 of N-acetylneuraminic acid (sialic acid), and these were distributed between six oligosaccharide units all of which were present on the heavy polypeptide chains. The oligosaccharide units showed two kinds of heterogeneity, which have been termed central and peripheral. Central heterogeneity was shown by the presence of three completely different core units, which had the following compositions: (1) 3 residues of d-galactose and 3 of 2-acetamido-2-deoxy-d-galactose, joined to protein by an O-glycosidic linkage between acetamidohexose and serine; (2) 3 residues of d-mannose, 2 of d-galactose and 3 of 2-acetamido-2-deoxy-d-glucose, joined to protein by an N-glycosidic linkage between acetamidohexose and aspartic acid; (3) 4 residues of d-mannose and 3 of 2-acetamido-2-deoxy-d-glucose with a linkage similar to that in (2). The core oligosaccharide units showed peripheral heterogeneity in the attachment of 6-deoxy-l-galactose, 2-acetamido-2-deoxy-d-glucose and N-acetylneuraminic acid. Tentative structures are proposed for these various types of oligosaccharide unit. Glycopeptides were isolated in which the sialic acid content exceeded that of d-galactose. Explanations are given for the electrophoretic mobility and staining characteristics of the various glycopeptides.


Holzforschung ◽  
2002 ◽  
Vol 56 (6) ◽  
pp. 607-614 ◽  
Author(s):  
C. Laine ◽  
T. Tamminen ◽  
A. Vikkula ◽  
T. Vuorinen

Summary In modern structural analysis of complex mixtures of wood polysaccharides, methylation analysis is still a valuable and powerful tool for linkage analysis. In this paper, methylation analysis is described for the procedure methylation, methanolysis, silylation and GC/MS. The retention time indexes for the partly methylated methyl glycosides of the relevant wood polysaccharides are listed together with the ratios of the isomers of the different structural units. A calculation model for relative molar response factors is suggested based on a published model for FID detection and on experimental data. Tested for oligosaccharides of known structure including xylotetraose, mannotriose and 63, 64-α-D-galactosyl-mannopentaose, the model gives reproducible and sufficiently correct results. The fate of xylose units substituted with 4-O-methyl glucuronic acid at position 2 is investigated with a model compound.


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