Selective precipitation and characterization of lignin–carbohydrate complexes (LCCs) from Eucalyptus

Planta ◽  
2018 ◽  
Vol 247 (5) ◽  
pp. 1077-1087 ◽  
Author(s):  
Bao-Cheng Zhao ◽  
Ji-Dong Xu ◽  
Bo-Yang Chen ◽  
Xue-Fei Cao ◽  
Tong-Qi Yuan ◽  
...  
2009 ◽  
Vol 68 (2) ◽  
pp. 193-198 ◽  
Author(s):  
A. García ◽  
A. Toledano ◽  
L. Serrano ◽  
I. Egüés ◽  
M. González ◽  
...  

1981 ◽  
Vol 199 (2) ◽  
pp. 341-350 ◽  
Author(s):  
T K Ng ◽  
J G Zeikus

An endoglucanase (1,4-beta-D-glucan glucanohydrolase, EC 3.2.1.4) was purified from Clostridium thermocellum by procedures that included centrifugation, ultrafiltration, selective precipitation, ion-exchange Sephadex chromatography and preparative gel electrophoresis. The 22-fold-purified enzyme behaved as a homogeneous protein under non-denaturing conditions. The enzyme represented a significant component (greater than 25%) of total extracellular endoglucanase activity, but was purified in low yield by the procedures employed. The native molecular weight of the endoglucanase was determined by ultracentrifugational analysis, amino acid composition and polyacrylamide-gel electrophoresis, and varied between 83000 and 94000. The enzyme contained 11.2% carbohydrate and was isoelectric at pH 6.72. The pH and temperature optima of the endoglucanase were 5.2 and 62 degrees C respectively. The enzyme lacked cysteine and was low in sulphur-containing amino acids. The purified endoglucanase displayed: high activity towards carboxymethylcellulose, celloheptaose, cellohexaose and cellopentaose; low activity towards Avicel microcrystalline cellulose and cellotetraose; no detectable activity towards cellotriose or cellobiose; increased activity towards cello-oligosaccharides with increasing degree of polymerization. The internal glycosidic bonds of cello-oligosaccharides were cleaved by the enzyme in preference to external linkages. The apparent Michaelis constant ([S]0.5V) and Vmax. for cellopentaose and cellohexaose hydrolysis were 2.30 mM and 39.3 mumol/min per mg of protein, and 0.56 mM and 58.7 mumol/min per mg of protein, respectively.


1974 ◽  
Vol 73 (3) ◽  
pp. 425-432 ◽  
Author(s):  
J. A. Morris ◽  
S. N. Hussaini

SummaryThe nature of the antibodies detectable by the microscopic agglutination test for bovine leptospirosis was examined. Density gradient ultracentrifugation, gel filtration and disulphide-bond-reduction experiments indicated that antileptospiral agglutinating activity was present in both IgM and IgG immunoglobulin fractions. This was confirmed by selective precipitation of specific antibody classes and ion-exchange chromatography.


1971 ◽  
Vol 17 (9) ◽  
pp. 1207-1216 ◽  
Author(s):  
J. Christison ◽  
S. M. Martin

The extracellular protease(s) of Cytophaga sp. is present naturally as a complex with acidic polysaccharides of the slime layer. The protein was separated from the slime by selective precipitation of the polysaccharide with a cationic detergent and the enzyme was purified about 100-fold by precipitation with alcohol and by chromatography on DEAE-cellulose. Inhibitor studies indicated that this alkaline protease was not of the trypsin/chymotrypsin type. Ca2+ had a strong stabilizing effect on the enzyme. The complex of basic protein (enzyme) and acidic slime polysaccharides has led to the conclusion that the enzyme is perhaps not truly extracellular but rather is surface bound. The slime layer would appear to have a role in attaching the bacterial cells to insoluble substrates as well as ensuring that degradative enzymes are kept in close contact with the substrate.


2020 ◽  
Author(s):  
S Reid ◽  
Ian Sims ◽  
LD Melton ◽  
AM Gane

The polymers secreted by suspension-cultured apple cells were composed of 85% carbohydrate (76% neutral sugar and 9% uronic acid) and 15% w/w protein. The extracellular polysaccharides (ECPs) contain 23% XG and 59% AGPs. The monosaccharide composition of the ECPs consisted of Gal, Ara, Glc and Xyl, with smaller amounts of Rha, Fuc and Man. Fractionation of the ECPs by anion-exchange chromatography yielded an unbound neutral fraction and a bound acidic fraction. Monosaccharide and linkage compositions of each fraction were determined. The neutral fraction (48% recovered carbohydrate) was composed of xyloglucan (XG;>90 mol%) which was purified by selective precipitation with Fehling's solution to yield pure XG. The purified XG had a Glc:Xyl:Gal:Fuc ratio of 4.0:2.5:0.8:0.5; the XG was not O-acetylated. The structure of the secreted XG was similar to that extracted from apple-pomace. The acidic fraction (52% recovered carbohydrate) was composed primarily of arabinogalactan-proteins (AGPs) as detected by the β-glucosyl Yariv diffusion test. The AGP had a Gal:Ara ratio of 1.3: 1.0. Minor amounts of arabinan, xylan and mannan were also detected in the ECPs. This study is the first examination of the polysaccharides secreted by apple cells grown in suspension culture.


2020 ◽  
Author(s):  
S Reid ◽  
Ian Sims ◽  
LD Melton ◽  
AM Gane

The polymers secreted by suspension-cultured apple cells were composed of 85% carbohydrate (76% neutral sugar and 9% uronic acid) and 15% w/w protein. The extracellular polysaccharides (ECPs) contain 23% XG and 59% AGPs. The monosaccharide composition of the ECPs consisted of Gal, Ara, Glc and Xyl, with smaller amounts of Rha, Fuc and Man. Fractionation of the ECPs by anion-exchange chromatography yielded an unbound neutral fraction and a bound acidic fraction. Monosaccharide and linkage compositions of each fraction were determined. The neutral fraction (48% recovered carbohydrate) was composed of xyloglucan (XG;>90 mol%) which was purified by selective precipitation with Fehling's solution to yield pure XG. The purified XG had a Glc:Xyl:Gal:Fuc ratio of 4.0:2.5:0.8:0.5; the XG was not O-acetylated. The structure of the secreted XG was similar to that extracted from apple-pomace. The acidic fraction (52% recovered carbohydrate) was composed primarily of arabinogalactan-proteins (AGPs) as detected by the β-glucosyl Yariv diffusion test. The AGP had a Gal:Ara ratio of 1.3: 1.0. Minor amounts of arabinan, xylan and mannan were also detected in the ECPs. This study is the first examination of the polysaccharides secreted by apple cells grown in suspension culture.


2007 ◽  
Vol 7 ◽  
pp. 77 ◽  
Author(s):  
Rajani Malla ◽  
Md Zeyaullah ◽  
Utprekshya Pokharel ◽  
Ajit Varma

Piriformospora indica produced only one form of intracellular acid phosphatase irrespective of the phosphate concentration and was purified. The enzyme was possibly a constitutive enzyme showing molecular mass of 66kDa as separated by SDS PAGE. Antibodies raised against cytosolic acid phosphatase of P. indica using gel band in native PAGE after selective precipitation of ammonium sulfate followed by gel filtration and ion exchange chromatography, gave productive antibody and immunoblotting analysis. Its reaction with native protein as well as denatured protein was significant. The antibody immunoprecipitated a single band of approximately 66kDa protein in SDS gel. The antibody localized the enzyme on the polyphosphate granules, cell-wall, vacuoles and cytoplasm of the mycelium indicating the possible sites of phosphate metabolism. <i> Nepal Journal of Science and Technology</i> Vol. 7, 2006


CrystEngComm ◽  
2018 ◽  
Vol 20 (27) ◽  
pp. 3868-3876 ◽  
Author(s):  
Yu Du ◽  
Jintao Gao ◽  
Xi Lan ◽  
Zhancheng Guo

A method of selective precipitation, in situ separation and ex situ characterization of rutile crystals from slag melt under super-gravity is proposed.


1986 ◽  
Vol 32 (4) ◽  
pp. 646-651 ◽  
Author(s):  
J Peynet ◽  
M Fénéant-Thibault ◽  
A Legrand ◽  
D Marot ◽  
F Rousselet ◽  
...  

Abstract An abnormal high-density lipoprotein (HDL) subfraction, detected during periods of mild jaundice in the serum of seven children with chronic cholestasis from birth, was isolated and characterized. This fraction, identified by its slow alpha electrophoretic migration, is present in addition to normal HDL and differs from the abnormal HDL previously described in cholestatic syndromes. It is devoid of apolipoprotein B but is precipitated by phosphotungstate-MgCl2. These properties allowed its isolation by double selective precipitation. This subfraction is undetectable with this procedure in the serum of healthy subjects, is rich in cholesterol, and contains a large amount of apolipoprotein E, which may explain its precipitation by phosphotungstate-MgCl2. These apo E-containing HDL may play a major role in the lipid metabolism of patients with long-standing cholestasis during periods of mild jaundice.


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