共查询到20条相似文献,搜索用时 15 毫秒
1.
Carvalho de Souza A Ganchev DN Snel MM van der Eerden JP Vliegenthart JF Kamerling JP 《Glycoconjugate journal》2009,26(4):457-465
Cell aggregation in the marine sponge Microciona prolifera is mediated by a multimillion molecular-mass aggregation factor, termed MAF. Earlier investigations revealed that the cell
aggregation activity of MAF depends on two functional domains: (i) a Ca2+-independent cell-binding domain and (ii) a Ca2+-dependent proteoglycan self-interaction domain. Structural analysis of involved carbohydrate fragments of the proteoglycan
in the self-association established a sulfated disaccharide β-d-GlcpNAc3S-(1→3)-α-l-Fucp and a pyruvated trisaccharide β-d-Galp4,6(R)Pyr-(1→4)-β-d-GlcpNAc-(1→3)-α-l-Fucp. Recent UV, SPR, and TEM studies, using BSA conjugates and gold nanoparticles of the synthetic sulfated disaccharide, clearly
demonstrated self-recognition on the disaccharide level in the presence of Ca2+-ions. To determine binding forces of the carbohydrate–carbohydrate interactions for both synthetic MAF oligosaccharides,
atomic force microscopy (AFM) studies were carried out. It turned out that, in the presence of Ca2+-ions, the force required to separate the tip and sample coated with a self-assembling monolayer of thiol-spacer-containing
β-d-GlcpNAc-(1→3)-α-l-Fucp-(1→O)(CH2)3S(CH2)6S- was found to be quantized in integer multiples of 30 ± 6 pN. No binding was observed between the two monolayers in the
absence of Ca2+-ions. Cd2+-ions could partially induce the self-interaction. In contrast, similar AFM experiments with thiol-spacer-containing β-d-Galp4,6(R)Pyr-(1→4)-β-d-GlcpNAc-(1→3)-α-l-Fucp-(1→O)(CH2)3S(CH2)6S- did not show a binding in the presence of Ca2+-ions. Also TEM experiments of gold nanoparticles coated with the pyruvated trisaccharide could not make visible aggregation
in the presence of Ca2+-ions. It is suggested that the self-interaction between the sulfated disaccharide fragments is stronger than that between
the pyruvated trisaccharide. 相似文献
2.
A. V. Perepelov Bin Liu S. N. Senchenkova A. S. Shashkov S. D. Shevelev Lu Feng Lei Wang Y. A. Knirel 《Biochemistry. Biokhimii?a》2010,75(1):19-24
On mild acid degradation of the lipopolysaccharide of Escherichia coli O108, the O-polysaccharide was isolated and studied by sugar analysis and one- and two-dimensional 1H- and 13C-NMR spectroscopy. The polysaccharide was found to contain an unusual higher sugar, 5,7-diacetamido-3,5,7,9-tetradeoxy-l-glycero-d-galacto-non-2-ulosonic acid (di-N-acetyl-8-epilegionaminic acid, 8eLeg5Ac7Ac). The following structure of the tetrasaccharide repeating unit of the polysac-charide
was established: →4)-α-8eLegp5Ac7Ac-(2→6)-α-D-Galp-(1→3)-α-L-FucpNAc-(1→3)-α-D-GlcpNAc-(1→. Functions of the E. coli O108 antigen biosynthetic genes, including seven putative genes for synthesis of 8eLeg5Ac7Ac, were assigned by sequencing
the O-antigen gene cluster along with comparison with gene databases and known biosynthetic pathways for related nonulosonic
acids. 相似文献
3.
Park Y Zhang Z Laremore TN Li B Sim JS Im AR Ahn MY Kim YS Linhardt RJ 《Glycoconjugate journal》2008,25(9):863-877
Acharan sulfate content from African giant snail (Achatina fulica) was compared in eggs and snails of different ages. Acharan sulfate was not found in egg. Acharan sulfate disaccharide →4)-α-d-GlcNpAc (1→4)-α-l-IdoAp2S(1→, analyzed by SAX (strong-anion exchange)–HPLC was observed soon after hatching and increases as the snails grow.
Monosaccharide compositional analysis showed that mole % of glucosamine, a major monosaccharide of acharan sulfate, increased
with age while mole % of galactose decreased with age. These results suggest that galactans represent a major energy source
during development, while acharan sulfate appearing immediately after hatching, is essential for the snail growth. The structures
of neutral N-glycans released from eggs by peptide N-glycosidase F (PNGase F), were next elucidated using ESI-MS/MS, MALDI-MS/MS, enzyme digestion, and monosaccharide composition
analysis. Three types of neutral N-glycan structures were observed, truncated (Hex2–4-HexNAc2), high mannose (Hex5–9-HexNAc2), and complex (Hex3-HexNAc2–10) types. None showed core fucosylation. 相似文献
4.
Sørensen HR Jørgensen CT Hansen CH Jørgensen CI Pedersen S Meyer AS 《Applied microbiology and biotechnology》2006,73(4):850-861
A novel α-l-arabinofuranosidase (α-AraF) belonging to glycoside hydrolase (GH) family 43 was cloned from Humicola insolens and expressed in Aspergillus oryzae. 1H-NMR analysis revealed that the novel GH43 enzyme selectively hydrolysed (1→3)-α-l-arabinofuranosyl residues of doubly substituted xylopyranosyl residues in arabinoxylan and in arabinoxylan-derived oligosaccharides. The optimal activity of the cloned enzyme was at pH 6.7 and 53 °C. Two other novel α-l-arabinofuranosidases (α-AraFs), both belonging to GH family 51, were cloned from H. insolens and from the white-rot basidiomycete Meripilus giganteus. Both GH51 enzymes catalysed removal of (1→2) and (1→3)-α-l-arabinofuranosyl residues from singly substituted xylopyranosyls in arabinoxylan; the highest arabinose yields were obtained with the M. giganteus enzyme. Combinations (50:50) of the GH43 α-AraF from H. insolens and the GH51 α-AraFs from either M. giganteus or H. insolens resulted in a synergistic increase in arabinose release from water-soluble wheat arabinoxylan in extended reactions at pH 6 and 40 °C. This synergistic interaction between GH43 and GH51 α-AraFs was also evident when a GH43 α-AraF from a Bifidobacterium sp. was supplemented in combination with either of the GH51 enzymes. The synergistic effect is presumed to be a result of the GH51 α-AraFs being able to catalyse the removal of single-sitting (1→2)–α-l-arabinofuranosyls that resulted after the GH43 enzyme had catalysed the removal of (1→3)–α-l-arabinofuranosyl residues on doubly substituted xylopyranosyls in the wheat arabinoxylan. 相似文献
5.
The rumen anaerobic fungusPiromonas communis, unlike the rumen anaerobic fungiNeocallimastix frontalis andNeocallimastix patriciarum, produced extracellular α-(4-O-methyl)-d-glucuronidase when grown in cultures containing filter-paper, barley straw, birchwood xylan or birchwood sawdust as carbon
source. The highest concentration of enzyme was produced in cultures containing birchwood sawdust. The aldobiouronic acidO-α-(4-O-methyl-d-glucopyran-osyluronic acid)-(1 → 2)-d-xylopyranose (MeGlcAXyl) was the best substrate of those tested: the aldotriouronic acidO-α-(4-O-methyl-d-glucopyranosyluronic acid (1 → 2)-O-\-d-xylopyranosyl-(1 → 4)-d-xylopyranose (MeGlcAXyl2) and the aldotetraouronic acidO-α-(4-O-methyl-d-glucopyranosyluronic acid)-(1 → 2)-O-\-d-xylopyranosyl-(1 → 4)-O-\-d-xylopyranosyl-(1 → 4)-d-xylopyranose (MeGlcAXyl3) were also attacked but the rate fell as the degree of polymerisation increased. When the same substituted xylooligosaccharides
were reduced to the corresponding alditols the enzyme activity disappeared. Similarly,p-nitrophenyl-α-d-glucuronide was not a substrate. Remarkably, the relative rates of attack shown by the α-(4-O-methyl)-d-glucuronidase on the aldouronic acids and on xylans extracted from birchwood, oat spelts and oat straw differed according
to the carbon source used to produce the enzyme. The α-(4-O-methyl)-d-glucuronidase had a pH optimum of 5.5 and a temperature optimum of 50°C. On gel filtration the enzyme was shown to be associated
with proteins covering the range 100–300 kDa, but a major peak of activity in the column effluent appeared to have a molecular
mass of 103 kDa. 相似文献
6.
Marie-Aleth Lacaille-Dubois Dieudonné Emmanuel Pegnyemb Olivier Placide Noté Anne-Claire Mitaine-Offer 《Phytochemistry Reviews》2011,10(4):565-584
The aim of this review is to highlight updated results on the biologically active saponins from Leguminosae-Mimosoideae. Acacic
acid-type saponins (AATS), is a class of very complex glycosides possessing a common aglycon unit of the oleanane-type (acacic
acid = 3β, 16α, 21β trihydroxy-olean-12-en-28 oic acid), having various oligosaccharide moieties at C-3 and C-28 and an acyl
group at C-21. About sixty molecules of this type have been actively explored in recent years from Leguminosae family, from
a chemical point of view and some fifty were reported to possess cancer related activities. These include cytotoxic/antitumor,
immunomodulatory, antimutagenic, and apoptosis inducing properties and appear to depend on the acylation and esterification
by different moieties at C-21 and C-28 of the acacic acid-type aglycone. One can observe that the (6S) configuration of the outer monoterpenyl moiety (MT) seems more potent in mediating high cytotoxicity than its (6R) isomer. Furthermore, the trisaccharide moiety {β-d-Xylopyranosyl-(1→2)-β-d-Fucopyranosyl-(1→6)- N-Acetamido 2-β-d-Glucopyranosyl-} at C-3, the tetrasaccharide moiety {β-d-Glucopyranosyl-(1→3)-[α-L-Arabinofuranosyl-(1→4)]-α-l-Rhamnopyranosyl-(1→2)-β-d-Glucopyranosyl} at C-28 of the aglycone, and the inner MT hydroxylated at its C-9, having a (6S) configuration can be important substituent patterns for the induction of apoptosis of AATS. Because of their interesting
cytotoxic/apoptosis inducing activity, some AATS can be useful in the search for new potential antitumor agents from Fabaceae.
Furthermore, the sequence 28-O-{Glc-(1→3)-[Araf-(1→4)]-Rha-(1→2)-Glc-Acacic acid}, often encountered in the genera Acacia, Albizia, Archidendron, and Pithecellobium may represent a chemotaxonomic marker of the Mimosoideae subfamily. 相似文献
7.
Elin Säwén Eine Huttunen Xue Zhang Zhennai Yang Göran Widmalm 《Journal of biomolecular NMR》2010,47(2):125-134
The use of lactic acid bacteria in fermentation of milk results in favorable physical and rheological properties due to in
situ exopolysaccharide (EPS) production. The EPS from S. thermophilus ST1 produces highly viscous aqueous solutions and its structure has been investigated by NMR spectroscopy. Notably, all aspects
of the elucidation of its primary structure including component analysis and absolute configuration of the constituent monosaccharides
were carried out by NMR spectroscopy. An array of techniques was utilized including, inter alia, PANSY and NOESY-HSQC TILT
experiments. The EPS is composed of hexasaccharide repeating units with the following structure: → 3)[α-d-Glcp-(1 → 4)]-β-d-Galp-(1 → 4)-β-d-Glcp-(1 → 4)[β-d-Galf-(1 → 6)]-β-d-Glcp-(1 → 6)-β-d-Glcp-(1 →, in which the residues in square brackets are terminal groups substituting backbone sugar residues that consequently
are branch-points in the repeating unit of the polymer. Thus, the EPS consists of a backbone of four sugar residues with two
terminal sugar residues making up two side-chains of the repeating unit. The molecular mass of the polymer was determined
using translational diffusion experiments which resulted in Mw = 62 kDa, corresponding to 64 repeating units in the EPS. 相似文献
8.
Begoña Gómez-Miranda Alicia Prieto Juan Antonio Leal Oussama Ahrazem Jesús Jiménez-Barbero Manuel Bernabé 《Glycoconjugate journal》2003,20(4):239-246
The alkali extractable and water-soluble cell wall polysaccharides F1SS from Aspergillus wentii and Chaetosartorya chrysella have been studied by methylation analysis, 1D- and 2D-NMR, and MALDI-TOF analysis. Their structures are almost identical,
corresponding to the following repeating unit:
[→ 3)-β-D-Galf-(1 → 5)-β-D-Galf-(1 →]
n
→ mannan core.
The structure of this galactofuranose side chain differs from that found in the pathogenic fungus Aspergillus fumigatus, in other Aspergillii and members of Trichocomaceae:
[→ 5)-β-D-Galf-(1 →]
n
→ mannan core.
The mannan cores have also been investigated, and are constituted by a (1 → 6)-α-mannan backbone, substituted at positions
2 by chains from 1 to 7 residues of (1 → 2) linked α-mannopyranoses. Published in 2004.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
9.
Lactococcus lactis subspecies cremoris SBT 0495 produces the phosphopolysaccharide viilian, which consists of the repeating unit β-d-glucosyl-(1→4)-(α-l-rhamnosyl-(1→2))-(α-d-galactose-1-phosphoryl-(→3)-β-galactosyl-(1→4)-β-d-glucose. A lipid extract was prepared from cells in the late exponential phase of growth and was hydrolyzed by hydrochloric
acid under mild conditions to split lipid-linked intermediates in the extract into lipid and sugar moieties. Both moieties
were purified by chromatographic techniques and were characterized to identify intermediates of the viilian biosynthetic pathway.
A polyisoprenoid isolated from the chloroform-soluble fraction of the hydrolyzed lipid extract was identified by mass spectrometry
as undecaprenol. Saccharides isolated from the water-soluble fraction of the hydrolyzed lipid extract by anion-exchange chromatography,
were characterized by glycosidic linkage analysis to discriminate sugar moieties of intermediates of viilian biosynthesis
from compounds liberated from cell wall components. Some oligosaccharide analogues contain a glycerol residue, suggesting
that these are fragments of glycosylglycerides and/or lipoteichoic acid. Three fragments were identified to be glucose, galactosyl-(1→4)-glucose,
and rhamnosyl-(1→2)-galactosyl-(1→4)-glucose, which are in agreement with the structure of the repeating unit of viilian.
These saccharides most likely represent the first three steps of the sequential assembly of the repeating unit of the undecaprenol
assembly.
Received: 2 November 1998 / Accepted: 3 March 1999 相似文献
10.
Jens Øbro Bernhard Borkhardt Jesper Harholt Michael Skjøt William G. T. Willats Peter Ulvskov 《Transgenic research》2009,18(6):961-969
Despite the wide occurrence of pectin in nature only a few source materials have been used to produce commercial pectins.
One of the reasons for this is that many plant species contain pectins with high levels of neutral sugar side chains or that
are highly substituted with acetyl or other groups. These modifications often prevent gelation, which has been a major functional
requirement of commercial pectins until recently. We have previously shown that modification of pectin is possible through
heterologous expression of pectin degrading enzymes in planta. To test the effect of simultaneous modification of the two main neutral pectic side chains in pectic rhamnogalacturonan
I (RGI), we constitutively expressed two different enzymes in Arabidopsis thaliana that would either modify the galactan or the arabinan side chains, or both side chains simultaneously. Our analysis showed
that the simultaneous truncation of arabinan and galactan side chains is achievable and does not severely affect the growth
of Arabidopsis thaliana. 相似文献
11.
Lipopolysaccharides (LPSs) of two strains Pragia fontium 97U116 and 27480 were isolated and characterized; they were close to those of other representatives of the family Enterobacteriaceae in fatty acid composition and contained, respectively, 3-hydroxytetradecanoic acid as the predominant component (45.8 and 45.1%), tetradecanoic (23.5 and 28.9%), hexadecanoic (12.6 and 7.9%), hexadecenoic (12.6 and 7.9%), and dodecanoic (4.9 and 4.2%) fatty acids. The O-specific polysaccharides consisted of linear penta- and tetrasaccharide repeating units: →2)-α-D-Galf-(1→3)-α-L-Rhap2Ac-(1→4)-α-D-GlcpNAc-(1→2)-α-L-Rhap-(1→3)-β-D-GlcpNAc-(1→ →4)-β-D-ManpNAc3NAcA-(1→2)-α-L-Rhap-(1→3)-β-L-Rhap-(1→4)-α-D-GlcpNAc-(1→ The LPSs of P. fontium 97U116 and 27480 were serologically active and belonged to different serogroups; they were less toxic than those of strain E. coli O55:B5, but more pyrogenic than the Pyrogenal preparation. 相似文献
12.
Heike Rau Ulrich Seydel Marina Freudenberg Jürgen Weckesser Hubert Mayer 《Archives of microbiology》1995,164(4):280-289
The structural elucidation of lipid A of the cell wall lipopolysaccharide (LPS) ofRhodospirillum salinarum 40 by chemical methods and laser desorption mass spectrometry revealed the presence of a mixed lipid A composed of three
different 1,4 bisphosphorylated β(1→6)-linked backbone hexosaminyl-hexosamine disaccharides, i.e. those composed of GlCN→GlcN,
2,3-diamino-2,3-dideoxy-d-Glc-(DAG)→DAG, and DAG→GlcN. Lipid A ofR. salinarum contained preferentially 3-OH-18:0 and 3-OH-14:0 as amide-linked andcisΔ11-18:1 and c19:0 as ester-linked fatty acids. The mass spectra of the liberated acyl-oxyacyl residues proved the concomitant
presence of 3-O-(cisΔ11-18:1)-18:0 and 3-O-(c19:0)-14:0 as the predominating diesters in this mixed lipid A. The glycosidically linked and the ester-linked phosphate
groups of the backbone disaccharide were neither substituted by ethanolamine phosphorylethanolamine, nor by 4-amino-4-deoxy-l-arabinose, in contrast to most of the enterobacterial lipid As. In the core oligosaccharide fraction, a HexA (1→4)HexA(1→5)Kdo-trisaccharide
was identified by methylation analysis. The terminal HexA (hexuronic acid) is possibly 4-OMe-GalA, a component described here
as an LPS constituent for the first time. LPS ofR. salinarum showed a lethality in C57BL/10 ScSN (LPS-responder)-mice) of an order of 10−1–10−2 of that reported forSalmonella abortus equi LPS, and it was also capable of inducing TNFα and IL6 in macrophages of C57BL/10ScSN mice. 相似文献
13.
Summary
Asclepias speciosa Torr, has latex-containing cells known as nonarticulated laticifers. In stem sections of this species, we have analyzed the
cell walls of nonarticulated laticifers and surrounding cells with various stains, lectins, and monoclonal antibodies. These
analyses revealed that laticifer walls are rich in (1→4) β-D-glucans and pectin polymers. Immunolocalization of pectic epitopes
with the antihomogalacturonan antibodies JIM5 and JIM7 produced distinct labeling patterns. JIM7 labeled all cells including
laticifers, while JIM5 only labeled mature epidermal cells and xylem elements. Two antibodies, LM5 and LM6, which recognize
rhamnogalacturonan I epitopes distinctly labeled laticifer walls. LM6, which binds to a (l→5) α-arabinan epitope, labeled
laticifer walls more intensely than walls of other cells. LM5, which recognizes a (1→4) β-D-galac-tan epitope, did not label
laticifer segments at the shoot apex but labeled more mature portions of laticifers. Also the LM5 antibody did not label cells
at the shoot apical meristem, but as cells grew and matured the LM5 epitope was expressed in all cells. LM2, a monoclonal
antibody that binds to β-D-glucuronic acid residues in arabinogalactan proteins, did not label laticifers but specifically
labeled sieve tubes. Sieve tubes were also specifically labeled byRicinus communis agglutinin, a lectin that binds to terminal β-D-galactosyl residues. Taken together, the analyses conducted showed that laticifer
walls have distinctive cytochemical properties and that these properties change along the length of laticifers. In addition,
this study revealed differences in the expression of pectin and arabinogalactan protein epitopes during shoot development
or among different cell types. 相似文献
14.
O-α-D-Galactopyranosyl-(1→2)-D-chiro-inositol, herein named fagopyritol B1, was identified as a major soluble carbohydrate (40% of total) in buckwheat (Fagopyrum esculentum Moench, Polygonaceae) embryos. Analysis of hydrolysis products of purified compounds and of the crude extract led to the
conclusion that buckwheat embryos have five α-galactosyl D-chiro-inositols: fagopyritol A1 and fagopyritol B1 (mono-galactosyl D-chiro-inositol isomers), fagopyritol A2 and fagopyritol B2 (di-galactosyl D-chiro-inositol isomers), and fagopyritol B3 (tri-galactosyl D-chiro-inositol). Other soluble carbohydrates analyzed by high-resolution gas chromatography included sucrose (42% of total), D-chiro-inositol, myo-inositol, galactinol, raffinose and stachyose (1% of total), but no reducing sugars. All fagopyritols were readily hydrolyzed
by α-galactosidase (EC 3.2.1.22) from green coffee bean, demonstrating α-galactosyl linkage. Retention time of fagopyritol B1
was identical to the retention time of O-α-D-galactopyranosyl-(1→2)-D-chiro-inositol from soybean (Glycine max (L.) Merrill, Leguminosae), suggesting that the α-ga-lactosyl linkage is to the 2-position of D-chiro-inositol. Accumulation of fagopyritol B1 was associated with acquisition of desiccation tolerance during seed development
and maturation in planta, and loss of fagopyritol B1 correlated with loss of desiccation tolerance during germination. Embryos
of seeds grown at 18 °C, a condition that favors enhanced seed vigor and storability, had a sucrose-to-fagopyritol B1 ratio
of 0.8 compared to a ratio of 2.46 for seeds grown at 25 °C. We propose that fagopyritol B1 facilitates desiccation tolerance
and storability of buckwheat seeds.
Received: 21 May 1997 / Accepted: 5 June 1997 相似文献
15.
Nazarenko EL Perepelov AV Shevchenko LS Daeva ED Ivanova EP Shashkov AS Widmalm G 《Biochemistry. Biokhimii?a》2011,76(7):791-796
Structure of the O-specific polysaccharide chain of the lipopolysaccharide (LPS) of Shewanella japonica KMM 3601 was elucidated. The initial and O-deacylated LPS as well as a trisaccharide representing the O-deacetylated repeating
unit of the O-specific polysaccharide were studied by sugar analysis along with 1H and 13C NMR spectroscopy. The polysaccharide was found to contain a rare higher sugar, 5,7-diacetamido-3,5,7,9-tetradeoxy-d-glycero-d-talo-non-2-ulosonic acid (a derivative of 4-epilegionaminic acid, 4eLeg). The following structure of the trisaccharide repeating
unit was established: →4)-α-4eLegp5Ac7Ac-(2→4)-β-d-GlcpA3Ac-(1→3)-β-d-GalpNAc-(1→. 相似文献
16.
Antimicrobial activity of crude seed extract of Moringa oleifera was investigated by thin layer chromatography bioassay against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Cladosporium cladosporioides, and Penicillium sclerotigenum; most of them were prominently inhibited by an isolate with R
F 0.92–0.96. Characterization and identification of the extract revealed the occurrence of three bioactive compounds: 4-(α-l-rhamnopyranosyloxy)benzyl isothiocyanate, methyl N-4-(α-l-rhamnopyranosyloxy) benzyl carbamate (both known compounds), and 4-(β-d-glucopyranosyl-1→4-α-l-rhamnopyranosyloxy)-benzyl thiocarboxamide, existence of which in any Moringa spp. or plant is reported for the first time. The UV spectrum of the novel compound showed maximum absorption at 273 and
225 nm in MeOH while the IR spectrum revealed several characteristic bands at 3100, 2900, 1700, 1500, 1300, 1100 and 1000
cm−1. The 1H-NMR showed signals at 1.2 and 3.77 ppm and the 13C-NMR presented signals at 155, 122, 91.7 and 98.4 ppm. All the compounds at 5 mg/L had very high bactericidal activity against
some of test pathogens even at contact period 1–2 h. 4-(β-d-Glucopyranosyl-1→4-α-l-rhamnopyranosyloxy)benzyl thiocarboxamide was the most potent, with 99.2 % inhibition toward Shigella dysenteriae and 100 % toward Bacillus cereus, E. coli and Salmonella typhi within 4 h of contact. 相似文献
17.
Feng B Hu W Ma BP Wang YZ Huang HZ Wang SQ Qian XH 《Applied microbiology and biotechnology》2007,76(6):1329-1338
It has been previously reported that a glucoamylase from Curvularia lunata is able to hydrolyze the terminal 1,2-linked rhamnosyl residues of sugar chains at C-3 position of steroidal saponins. In
this work, the enzyme was isolated and identified after isolation and purification by column chromatography including gel
filtration and ion-exchange chromatography. Analysis of protein fragments by MALDI-TOF/TOF™ proteomics Analyzer indicated
the enzyme to be 1,4-alpha-D-glucan glucohydrolase EC 3.2.1.3, GA and had considerable homology with the glucoamylase from Aspergillus oryzae. We first found that the glucoamylase was produced from C. lunata and was able to hydrolyze the terminal rhamnosyl of steroidal saponins. The enzyme had the general character of glucoamylase,
which hydrolyze starch. It had a molecular mass of 66 kDa and was optimally active at 50°C, pH 4, and specific activity of
12.34 U mg of total protein−1 under the conditions, using diosgenin-3-O-α-L-rhamnopyranosyl(1→4)-[α-L-rhamnopyranosyl (1→2)]-β-D-glucopyranoside (compound II) as the substrate. Furthermore, four kinds of commercial glucoamylases from Aspergillus niger were investigated in this work, and they had the similar activity in hydrolyzing terminal rhamnosyl residues of steroidal
saponin.
This project was supported by the National Natural Science Foundation of China (NSFC; 30572333). 相似文献
18.
Modification of cambial cell wall architecture during cambium periodicity in Populus tomentosa Carr.
Hui-Min Chen Jia-Jia Han Ke-Ming Cui Xin-Qiang He 《Trees - Structure and Function》2010,24(3):533-540
Cambium periodicity is correlated with changes in the cambial cell wall, but the heterogeneity of cell wall structure and
composition makes it difficult to give an accurate interpretation, especially for complex secondary vascular tissues. A combination
of different methods is necessary to reveal the structure of this complex cell wall. In this study, the cell wall architecture
and composition of active and dormant cambial cells in Populus tomentosa were investigated by a combination of light microscopy, rapid-freezing and deep-etching electron microscopy, Fourier-transform
infrared microspectroscopy and immuno-histochemistry. The results showed that the architecture of dormant cambial cell walls
displayed a multi-layered structure, denser fibril network, smaller pore size, and fewer crosslinks between microfibrils than
active cambial cell walls. The FTIR spectra of cell walls from active and dormant cambium showed differences in the intensity
of bands near 1,740, 1,629, 1,537, 1,240, and 830 cm−1, which reflected differences in cell wall composition. Immuno-labeling indicated that high methyl-esterified homogalacturonan
and (1 → 4)-β-d-galactan epitopes were abundant and distributed in active cambial cell walls, and relatively de-esterified homogalacturonan
and (1 → 5)-α-l-arabinan epitopes had weak labeling in the active cambium, while almost no labeling or very weak labeling for high methyl-esterified
homogalacturonan, (1 → 4)-β-d-galactan and (1 → 5)-α-l-arabinan epitopes occurred in dormant cambial cells, except for the de-esterified homogalacturonan epitope, which was abundant
in dormant cambial cells. These results demonstrate that there are great differences, both in structure and composition, between
active and dormant cambial cell walls, which reflect their dynamic changes during cambium activity. 相似文献
19.
Yuzuru Suzuki Kazumi Oishi Hajime Nakano Takashi Nagayama 《Applied microbiology and biotechnology》1987,26(6):546-551
Summary A p-nitrophenyl-α-d-glucopyranoside-hydrolysing oligo-1,6-glucosidase (dextrin 6-α-d-glucanohydrolase, EC 3.2.1.10) of Bacillus sp. KP 1071 capable of growing at 30°–66°C was purified to homogeneity. The molecular weight was estimated to be 62,000.
The amino-terminal amino acid was methionine. The enzyme shared its antigenic groups in part with its homologous counterpart
from Bacillus thermoglucosidasius KP 1006 (obligate thermophile), but did not at all with any one of oligo-1,6-glucosidases from Bacillus cereus ATCC 7064 (mesophile), Bacillus coagulans ATCC 7050 (facultative thermophile) and Bacillus flavocaldarius KP 1288 (extreme thermophile). A comparison of amino acid composition showed that the proline content increased greatly in
a linearity with the rise in thermostability in the order, mesophile → facultative thermophile → KP 1071 → obligate thermophile
→ extreme thermophile enzymes.
Presented at the Annual Meeting of the Agricultural Chemical Society of Japan, Kyoto, April 3, 1986 相似文献
20.
Isolation and Culture of a Marine Bacterium Degrading the Sulfated Fucans from Marine Brown Algae 总被引:1,自引:0,他引:1
Descamps V Colin S Lahaye M Jam M Richard C Potin P Barbeyron T Yvin JC Kloareg B 《Marine biotechnology (New York, N.Y.)》2006,8(1):27-39
Fucoidans are matrix polysaccharides from marine brown algae, consisting of an α-l-fucose backbone substituted by sulfate-ester groups and masked with ramifications containing other monosaccharide residues.
In spite of their interest as biologically active compounds in a number of homologous and heterologous systems, no convenient
sources with fucanase activity are available yet for the degradation of the fucalean algae. We here report on the isolation,
characterization, and culture conditions of a bacterial strain capable of degrading various brown algal fucoidans. This bacterium,
a member of the family Flavobacteriaceae, was shown to secrete fucoidan endo-hydrolase activity. An extracellular enzyme preparation was used to degrade the fucoidan
from the brown alga Pelvetia canaliculata. End products included a tetrasaccharide and a hexasaccharide made of the repetition of disaccharidic units consisting of
α-1→3-l-fucopyranose-2-sulfate-α-1→4-l-fucopyranose-2,3-disulfate, with the 3-linked residues at the nonreducing end. 相似文献