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1.
J Alroy A Bachrach J G Thalhammer N Panjwani R Richard R DeGasperi C D Warren D M Albert S S Raghavan 《Virchows Archiv. B, Cell pathology including molecular pathology》1991,60(3):173-180
The clinical, neurophysiological, morphological and biochemical manifestation of eyes from Persian kittens affected with alpha-mannosidosis were studied. Clinically the disease is characterized by progressive corneal and lenticular opacification. In addition there is asymmetry in shape and latency of signal conductions which were demonstrated by visual evoked potential studies. Morphological and histochemical studies revealed vacuolization of various ocular cell types which stained positively with Concanavalia ensiformis agglutinin (Con A) and wheat germ agglutinin (WGA). Biochemical studies illustrated low activity of acid alpha-mannosidase in cultured keratocytes and abnormal storage of partially degraded oligosaccharides in these cells, in vitreous humor and lens. This comprehensive study of ocular alpha-mannosidosis demonstrates enzyme deficiency which leads to abnormal storage of oligosaccharides in affected cells and is manifested by morphological alterations and functional impairment. 相似文献
2.
Endoplasmic reticulum α-1,2 mannosidase I (ERManI) is an enzyme, which removes α(1-2) linked mannoses from asparagine-linked
oligosaccharides on glycoproteins in the endoplasmic reticulum (ER). ERManI preferentially removes one α(1-2) linked mannose
from B-chain of Man9GlcNAc2. When glycoproteins fail to achieve properly folding, increased removal of α(1-2) linked mannoses on their oligosaccharides
is induced and leads them to be disposed and degraded by ER-associated degradation pathway. However, it is still inconclusive
whether accelerated removal of α(1-2) linked mannoses on those glycoproteins is catalyzed by the α-1,2 mannosidase I, proteins
similar to mannosidase I [e.g. ER degradation-enhancing α-1,2 mannosidase-like protein (EDEM)], or both of them. Therefore, to approach this issue, we have
investigated its in vitro activities using various oligosaccharides and glycoproteins as substrates. A recombinant form of human ERManI (hERManI) was
prepared by using Escherichia coli. First, the enzyme generated Man6GlcNAc2-PA and Man5GlcNAc2-PA from 100 μM Man9GlcNAc2-PA after a one-hour reaction. Second, we have exposed bovine thyroglobulin and soybean agglutinin to denaturing conditions,
e.g. 8 M urea, and used those glycoproteins as substrates. Sugar moieties were released from the reactant by PNGase F and their
structures and amounts were elucidated by HPLC analysis. Intriguingly, the enzyme was shown to remove mannoses from bovine
thyroglobulin and soybean agglutinin to larger extents when they were exposed to a denaturant. Therefore, our results suggested
that hERManI could recognize tertiary and/or quaternary structures of glycoproteins and remove more α-1,2 linked mannoses
from misfolded glycoproteins in living cells. 相似文献
3.
Galder Valbuena Juan Francisco Madrid Francisco Hernández Francisco José Sáez 《Histochemistry and cell biology》2010,134(2):215-225
Glycoconjugates play roles in many physiological and pathological processes. Previous works have shown important functions
mediated by glycans in spermatogenesis, and the carbohydrate composition of testis has been studied by several approaches,
including lectin-histochemical methods. However, the testis of Xenopus laevis, an animal model extensively employed in biochemical, cell and developmental research, has not yet been analysed. The aim
of this work was to carry out a histochemical study of the fucose (Fuc)-containing glycoconjugates of Xenopus testis by means of lectins, combined with deglycosylation pretreatments. Four Fuc-binding lectins were used: orange peel
(Aleuria aurantia) lectin (AAL), gorse seed (Ulex europaeus) agglutinin-I (UEA-I), fresh water eel (Anguilla anguilla) agglutinin (AAA), and asparagus pea (Lotus tetragonolobus) agglutinin (LTA), each recognizing different forms of fucosylated glycans. Labelling with UEA-I, which preferably binds
Fucα(1,2) containing oligosaccharides, did not show any appreciable staining. LTA, specific for Fucα(1,3), and AAA, which
binds Fucα(1,2), labelled spermatocytes and spermatids, but no labelling was seen when the histochemical procedure was carried
out after either β-elimination (which removes O-linked oligosaccharides) or incubation with PNGase F (which removes N-linked
oligosaccharides), suggesting that fucosylated glycans are of both N- and O-linked types. AAL, which has its highest affinity
to Fucα(1,6), but also recognizes Fucα(1,2) and Fucα(1,3), labelled the whole testis, and the staining remained when the histochemical
method was performed after either β-elimination or incubation with PNGase F. Labelling with AAL could be explained by the
fact that this lectin could be binding to diverse fucosylated glycans in N- and O-glycans, and even in glycolipids. The importance of these glycans is discussed. 相似文献
4.
Stephanie D. Boomkamp J. S. Shane Rountree David C. A. Neville Raymond A. Dwek George W. J. Fleet Terry D. Butters 《Glycoconjugate journal》2010,27(3):297-308
Sandhoff and Tay-Sachs disease are autosomal recessive GM2 gangliosidoses where a deficiency of lysosomal β-hexosaminidase
results in storage of glycoconjugates. Imino sugar (2-acetamido-1,4-imino-1,2,4-trideoxy-L-arabinitol) inhibition of β-hexosaminidase
in murine RAW264.7 macrophage-like cells led to lysosomal storage of glycoconjugates that were characterised structurally
using fluorescence labelling of the free or glycolipid-derived oligosaccharides followed by HPLC and mass spectrometry. Stored
glycoconjugates were confirmed as containing non-reducing GlcNAc or GalNAc residues resulting from the incomplete degradation
of N-linked glycoprotein oligosaccharide and glycolipids, respectively. When substrate reduction therapeutics N-butyl-deoxynojirimycin (NB-DNJ) or N-butyldeoxygalactonojirimycin (NB-DGJ) were applied to the storage phenotype cells, an increase in glucosylated and galactosylated oligosaccharide species
was observed due to endoplasmic reticulum α-glucosidases and lysosomal β-galactosidase inhibition, respectively. Hexosaminidase
inhibition triggered a tightly regulated cytokine-mediated inflammatory response that was normalised using imino sugars NB-DNJ and NB-DGJ, which restored the GM2 ganglioside storage burden but failed to reduce the levels of GA2 glycolipid or glycoprotein-derived
N-linked oligosaccharides. Using a chemically induced gangliosidosis phenotype that can be modulated with substrate lowering
drugs, the critical role of GM2 ganglioside in the progression of inflammatory disease is also demonstrated. 相似文献
5.
Kogure T Suzuki T Takahashi T Miyamoto D Hidari KI Guo CT Ito T Kawaoka Y Suzuki Y 《Glycoconjugate journal》2006,23(1-2):101-106
We reported previously that the dominant receptors of influenza A and B viruses, and human and murine respiroviruses, were
sialylglycoproteins and gangliosides containing monosialo-lactosamine type I-and II-residues, such as sialic acid-α2-3(6)-Galβ1-3(4)-GlcNAcβ1-. In addition, the Siaα2-3Gal linkage was predominantly recognized by avian and horse influenza viruses, and human parainfluenza
virus type 1 (hPIV-1), whereas the Siaα2-6Gal linkage was mainly recognized by human influenza viruses (Paulson JC in “The
Receptors' [Conn M Ed] 2, 131–219 (1985); Suzuki Y, Prog Lipid Res 33, 429–57 (1994); Ito T, J Virol 73, 6743–51 (2000); Suzuki Y, J Virol 74, 11825–31 (2000); Suzuki T, J. Virol 75, 4604–4613 (2001); Suzuki Y, Biol. Pharm. Bull. 28, 399–408 (2005)). To clarify the distribution of influenza virus receptors on the human bronchial epithelium cell surface,
we investigated a primary culture of normal human bronchial epithelial (NHBE) cells using two types of lectin (MAA and SNA),
which recognize sialyl linkages (α2-3 and α2-6), using fluorescence-activated cell-sorting analysis. The results showed that
both α2-3- and α2-6-linked Sias were expressed on the surface of primary human bronchial epithelial cells. The cells infected
by hPIV-1 bound to MAA, confirming that cells targeted by hPIV-1 have α2-3-linked oligosaccharides. We also compared the ability
of hPIV-1 and human influenza A virus to infect primary human bronchial epithelial cells pre-treated with Siaα2-3Gal-specific
sialidase from Salmonella typhimurium. No difference was observed in the number of sialidase pre-treated and non-treated cells infected with human influenza A
virus, which binds to Siaα2-6Gal-linked oligosaccharides. By contrast, the number of cells infected with hPIV-1 decreased
significantly upon sialidase treatment. Thus, cultured NHBE cells showed both α2-3-linked Sias recognized by hPIV-1 and avian
influenza virus receptors, and α2-6-linked Sias recognized by human influenza virus receptors. 相似文献
6.
Dolores Solis Juan J Calvete Libia Sanz Christiane Hettel Manfred Raida Teresa Diaz-Maurino Edda Topfer-Petersen 《Glycoconjugate journal》1997,14(2):275-280
Lectin mapping, carbohydrate analysis and electrospray mass spectrometry of boar seminal plasma PSP-II glycoforms show that
its single N-glycosylation site displays a repertoire of carbohydrate structures consisting of the basic pentasaccharide core
Manα 1–6[Manα 1–3]Manβ1-4GlcNAcβ1-4GlcNAc with a fucosyl residue α1-6-linked to the innermost N-acetylglucosamine residue. Other glycoforms display fucosylated hybrid-type or monoantennary complex-type chains, some of
which contain α2-6-linked sialic acid. N-acetylgalactosamine, possibly in Galβ1-3GalNAc sequence, is present in most of the PSP-II glycoforms. Abbreviations: PSP-I and PSP-II, porcine seminal plasma proteins
I and II; PNGaseF, peptide-N4-(N-acetyl-β-D-glucosaminyl) asparagine amidase (EC 3.5.1.52) from Flavobacterium meningosepticum;
ConA, Cannavalia ensiformis (jack bean) agglutinin; GNA, Galanthus nivalis (snowdrop) agglutin; SNA, Sambucus nigra (elderberry)
agglutinin; MAA, Maackia amurensis (maakia) agglutinin; PNA, Arachis hypogaea (peanut) agglutinin; DSA, Datura stramonium
(jimson weed) agglutinin; AAA, Aleuria aurantia agglutinin
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献
7.
Unlike their counterparts in budding yeast Saccharomyces cerevisiae, the glycoproteins of Schizosaccharomyces pombe contain, in addition to α-d-mannose (Man), a large number of α-d-galactose (Gal) residues. In both yeasts, large outer chains are attached to the oligosaccharide cores of glycoproteins during
export via Golgi. Formation of the yeast-specific large outer chain is initiated by α-1,6-mannosylatransferase encoded by
the och1
+ gene, the disruption of which blocked outer chain elongation. We previously reported that N-linked oligosaccharide structures of S. pombe och1Δ mutant consisted of Gal2–6Man9GlcNAc2 with α-linked Gal residues attached to the core oligosaccharide moiety. The disruption of gms1
+, a gene encoding the UDP-galactose transporter required for the synthesis of galactomannan, abolished cell surface galactosylation
in S. pombe. In this study, we constructed a gms1Δoch1Δ double mutant and determined the N- and O-linked oligosaccharide structures present on the cell surface. Oligosaccharides were liberated from glycoproteins by hydrazinolysis
and labeled with the fluorophore, 2-aminopyridine. The pyridylaminated N-linked oligosaccharides were analyzed by high-performance liquid chromatography in combination with α1,2-mannosidase digestion
and partial acetolysis. These analyses revealed that the N-linked oligosaccharides of gms1Δoch1Δ cells consisted of α1,2-linked Man-extended core oligosaccharides (Man8–12GlcNAc2) from which the fission yeast-specific α-linked Gal residues were completely absent. 相似文献
8.
Oyamada H Ogawa Y Shibata N Okawa Y Suzuki S Kobayashi H 《Archives of microbiology》2008,189(5):483-490
We investigated the structural and immunochemical characteristics of cell wall mannan obtained from Candida sojae JCM 1644, which is a new yeast species isolated from defatted soybean flakes. The results of a slide-agglutination test and
of an enzyme-linked immunosorbent assay using anti-factor sera to the pathogenic Candida species indicated that the cells and the C. sojae mannan were cross-reactive to the specific anti-factor sera against Candida albicans serotype A (FAb 6) and Candida guilliermondii (FAb 9). Two-dimensional homonuclear Hartmann–Hahn analysis indicated that the mannan consisted of various linked oligomannosyl
side chains containing α-1,2-, α-1,3-, α-1,6- and β-1,2-linked mannose residues. However, although the determinants of antigenic
factors 6 and 9 could be not found in this mannan, branched side chains, Manβ1-2Manα1-3[Manα1-6]Manα1-(2Manα1-)n2Man and a
linear α-1,6-linked polymannosyl backbone, which are cross-reacted by FAbs 6 and 9, respectively, were identified. The mannan
was subjected to acetolysis in order to determine the polymerization length of the α-1,2-linked oligomannosyl residue in the
side chains. The result of 1H-nuclear magnetic resonance analysis of the released oligosaccharides showed that the remarkable regularity in the length
of α-1,2-linked oligomannosyl side chains, which were previously found in mannans of other Candida species, is not observed in this mannan. 相似文献
9.
A new mannose-binding lectin was isolated from Sternbergia lutea bulbs by affinity chromatography on an α(1-2)mannobiose-Synsorb column and purified further by gel filtration. This lectin
(S. lutea agglutinin; SLA) appeared homogeneous by native-gel electrophoresis at pH 4.3, gel filtration chromatography on a Sephadex
G-75 column, and SDS-polyacrylamide gel electrophoresis, These data indicate that SLA is a dimeric protein (20 kDa) composed
of two identical subunits of 10 kDa which are linked by non-covalent interactions.
The carbohydrate binding specificity of the lectin was investigated by quantitative precipitation and hapten inhibition assays.
It is an α-D-mannose-specific lectin that interacts to form precipitates with various α-mannans, galactomannan and asialo-thyroglobulin,
but not with α-glucans and thyroglobulin. Of the monosaccharides tested only D-mannose was a hapten inhibitor of the SLA-asialothryroglobulin
precipitation system, whereas D-glucose, D-galactose and L-arabinose were not. The lectin appears to be highly specific for
terminal α(1-3)-mannooligosaccharides. The primary structure of SLA appears to be quite similar to that of the snow drop (Galanthus nivalis) bulb lectin which is a mannose-binding lectin from the same plant family Amaryllidaceae. The N-terminal 46 amino acid sequence
SLA showed 7% homology with that of GNA. Abbreviations: AAA, Allium ascalonicum agglutinin (shallot lectin); ASA, Allium sativum
agglutinin (garlic lectin); AUA, Allium ursinum agglutinin (ramsons lectin); DAP, 1,3-diaminopropane; GNA, Galanthus nivalis
agglutinin (snowdrop lectin); HHA, Hippeastrum hybr. agglutinin (amaryllis lectin); LOA, Listera ovata agglutinin (orchid
twayblade lectin); NPA, Narcissus pseudonarcissus agglutinin (daffodil lectin); PAGE, polyacrylamide gel electrophoresis;
PBS, phosphate-buffered saline, SLA, Sternbergia lutea agglutinin; SDS, sodium dodecyl sulfate; Me, methyl; Bn, benzyl; PNP,
p-nitrophenyl.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
10.
11.
In this study, a new α-glucosidase gene from Thermoanaerobacter ethanolicus JW200 was cloned and expressed in Escherichia coli by a novel heat-shock vector pHsh. The recombinant α-glucosidase exhibited its maximum hydrolytic activity at 70°C and pH 5.0∼5.5. With p-nitrophenyl-α-D-glucoside as a substrate and under the optimal condition (70°C, pH 5.5), K
m and V
max of the enzyme was 1.72 mM and 39 U/mg, respectively. The purified α-glucosidase could hydrolyze oligosaccharides with both α-1,4 and α-1,6 linkages. The enzyme also had strong transglycosylation activity when maltose was used as sugar donor. The transglucosylation
products towards maltose are isomaltose, maltotriose, panose, isomaltotriose and tetrasaccharides. The enzyme could convert
400 g/L maltose to oligosaccharides with a conversion rate of 52%, and 83% of the oligosaccharides formed were prebiotic isomaltooligosaccharides
(containing isomaltose, panose and isomaltotriose). 相似文献
12.
Summary Cultures of bovine oviduct epithelial cells are widely used in co-culture systems to improve the results ofin vitro fertilization. The aim of the present study was to evaluate the suitability of S-100 protein as a differentiation marker
for bovine oviduct epithelial cellsin vitro. The distribution of S-100α and S-100β was examined immunohistochemically in bovine oviduct epitheliumin situ and in primary cell cultures derived from it. Three segments of the Fallopian tube (isthmus, ampulla and fimbriae) were compared
and analysed during different stages of the oestrus cycle (luteal phase and follicular phase). Ciliated and non-ciliated cells
of the epithelium reacted with anti-S-100α, S-100a(αβ) and S-100β antibodies, except for isthmic non-ciliated cells, which
did not bind anti-S-100β or anti-S-100a(αβ). In addition, basal cells never showed immunoreactivity for S-100. In confluent
monolayers of cultured oviduct epithelial cells, disappearance of reactivity for S-100 paralleled morphological signs of dedifferentiation
(loss of cilia, cytoplasmic vacuolization). Free-floating oviduct epithelial cells, in contrast, retained morphological differentiation
and still expressed S-100 antigen even after seven daysin vitro. The immunohistochemical findings were confirmed by polyacrylamide gel electrophoresis and Western blotting. The results
indicate that the presence of S-100 is closely connected to morphological differentiation and to the specific functional condition
of bovine oviduct epithelial cells. 相似文献
13.
Summary In this study, the variety of sugar residues in the gut glycoconjugates of Triturus carnifex (Amphibia, Caudata) are investigated by carbohydrate conventional histochemistry and lectin histochemistry. The oesophageal
surface mucous cells contained acidic glycoconjugates, with residues of GalNAc, Gal β1,3 GalNAc and (GlcNAc β1,4)
n
oligomers. The gastric surface cells mainly produced neutral glycoproteins with residues of fucose, Gal β1-3 GalNAc, Gal-αGal,
and (GlcNAc β1,4)
n
oligomers in N- and O-linked glycans, as the glandular mucous neck cells, with residues of mannose/glucose, GalNAc, Gal β1,3
GalNAc, (GlcNAc β1,4)
n
oligomers and fucose linked α1,6 or terminal α1,3 or α1,4 in O-linked glycans. The oxynticopeptic tubulo-vesicular system
contained neutral glycoproteins with N- and O-linked glycans with residues of Gal-αGal, Gal β1-3 GalNAc and (GlcNAc β1,4)
n
oligomers; Fuc linked α1,2 to Gal, α1,3 to GlcNAc in (poly)lactosamine chains and α1,6 to GlcNAc in N-linked glycans. Most
of these glycoproteins probably corresponds to the H+K+-ATPase β-subunit. The intestinal goblet cells contained acidic glycoconjugates, with residues of GalNAc, mannose/ glucose,
(GlcNAc β1,4)
n
oligomers and fucose linked α1,2 to Gal in O-linked oligosaccharides. The different composition of the mucus in the digestive
tracts may be correlated with its different functions. In fact the presence of abundant sulphation of glycoconjugates, mainly
in the oesophagus and intestine, probably confers resistance to bacterial enzymatic degradation of the mucus barrier. 相似文献
14.
Van Laere KM Hartemink R Beldman G Pitson S Dijkema C Schols HA Voragen AG 《Applied microbiology and biotechnology》1999,52(5):681-688
Bifidobacterium adolescentis, a gram-positive saccharolytic bacterium found in the human colon, can, alongside other bacteria, utilise stachyose in vitro
thanks to the production of an α-galactosidase. The enzyme was purified from the cell-free extract of Bi. adolescentis DSM 20083T. It was found to act with retention of configuration (α→α), releasing α-galactose from p-nitrophenyl galactoside. This hydrolysis probably operates with a double-displacement mechanism, and is consistent with the
observed glycosyltransferase activity. As α-galactosides are interesting substrates for bifidobacteria, we focused on the
production of new types of α-galactosides using the transgalactosylation activity of Bi. adolescentisα-galactosides. Starting from melibiose, raffinose and stachyose oligosaccharides could be formed. The transferase activity
was highest at pH 7 and 40 °C. Starting from 300 mM melibiose a maximum yield of 33% oligosaccharides was obtained. The oligosaccharides
formed from melibiose were purified by size-exclusion chromatography and their structure was elucidated by NMR spectroscopy
in combination with enzymatic degradation and sugar linkage analysis. The trisaccharide α-d-Galp-(1 → 6)-α-d-Galp-(1 → 6)-d-Glcp and tetrasaccharide α-d-Galp-(1 → 6)-α-d-Galp-(1 → 6)-α-d-Galp-(1 → 6)-d-Glcp were identified, and this indicates that the transgalactosylation to melibiose occurred selectively at the C-6 hydroxyl group
of the galactosyl residue. The trisaccaride α-d-Galp-(1 → 6)-α-d-Galp-(1 → 6)-d-Glcp formed could be utilised by various intestinal bacteria, including various bifidobacteria, and might be an interesting pre-
and synbiotic substrate.
Received: 15 March 1999 / Received revision: 8 June 1999 / Accepted: 11 June 1999 相似文献
15.
Chemical modification of carbohydrates can lead to differences in their biological activities. We previously showed that κ-carrageenan
oligosaccharides from Kappaphycus striatum have antitumor and immunomodulation effects on S180-bearing mice. In this study, we tested the hypothesis that different
chemical modifications of carrageenan oligosaccharides enhance their activities. The mice inoculated with S180 cell suspension
were treated p.o. with carrageenan oligosaccharides and their sulfated, acetylated, and phosphorylated derivatives (50, 100,
and 200 μg g−1) for 14 days. Transplantable tumor inhibition rate and macrophage phagocytosis, quantitative hemolysis of sheep red blood
cells, lymphocyte proliferation, the activity of natural killer cells, production of interleukin-2, and tumor necrosis factor-α
were also analyzed. As expected, treatment with different κ-carrageenan oligosaccharides derivatives resulted in an increase
in tumor inhibition rate and macrophage phagocytosis and cellular immunity, especially on spleen lymphocyte proliferation.
The sulfated derivative at the dose 200 μg g−1 per day showed the highest antitumor activity with the 54.12% tumor weight inhibition and elicited an increase in nature
killer cells activity up to 76.1% on S180-bearing mice, which were both significantly higher than the unmodified oligosaccharides.
It suggested that chemical modification (especially sulfation) of carrageenan oligosaccharides can enhance their antitumor
effect and boost their antitumor immunity. 相似文献
16.
17.
Yoshikatsu Matsubayashi Akiko Morita Emi Matsunaga Akiko Furuya Nobuo Hanai Youji Sakagami 《Planta》1999,207(4):559-565
The aim of this research was to determine whether the production of the mitogenic peptide, phytosulfokine-α (PSK-α), is affected
by auxin and/or cytokinin, and whether the expression of the biological activity of PSK-α requires the presence of these plant
hormones. We developed a competition enzyme-linked immunosorbent assay system that measures the amount of PSK-α using a polyclonal
antibody. In suspension-cultured mesophyll cells of Asparagus officinalis L., the production of PSK-α was first detected after 48 h of culture, prior to the first cell division which was generally
observed after 96 h of culture when both 1-napthaleneacetic acid and N6-benzyladenine were present in the medium. No significant amount of PSK-α was, however, produced when one of these plant hormones
was eliminated from the medium. We also characterized the progression of the cell cycle triggered by PSK-α using a fluorescent
dye and microdensitometry. Asparagus mesophyll cells immediately after isolation were arrested in G0/G1, and the cell cycle proceeded only when all three factors, 1-naphthaleneacetic acid, N6-benzyladenine, and PSK-α, existed in the medium. These results show that the production and the expression of biological
activity of PSK-α is closely correlated with the signal transduction pathway mediated by auxin and cytokinin.
Received: 26 June 1998 / Accepted: 11 November 1998 相似文献
18.
S Koizumi T Endo K Tabata H Nagano J Ohnishi A Ozaki 《Journal of industrial microbiology & biotechnology》2000,25(4):213-217
A large-scale production system of GDP-fucose (GDP-Fuc) and fucosylated oligosaccharides was established by the combination
of recombinant Escherichia coli cells overexpressing GDP-Fuc biosynthetic genes and Corynebacterium ammoniagenes cells. E. coli cells overexpressed the genes for glucokinase, phosphomannomutase, mannose-1-phosphate guanylyltransferase, GDP-mannose (GDP-Man)
dehydratase, and GDP-4-keto-6-deoxy-mannose (GKDM) epimerase/reductase as well as phosphoglucomutase and phosphofructokinase.
C. ammoniagenes contributed to the formation of GTP from GMP. GDP-Fuc accumulated to 29 mM (18.4 g l−1) after a 22-h reaction starting with GMP and mannose through introducing the two-step reaction to overcome the inhibition
of GDP-Fuc on GDP-Man dehydratase activity. When E. coli cells overexpressing the α1,3-fucosyltransferase gene of Helicobacter pylori were put into the GDP-Fuc production system, Lewis X [Galβ1–4(Fucα1–3)GlcNAc] was produced at an amount of 40 mM (21 g l−1) for 30 h from GMP, mannose, and N-acetyl lactosamine. The production system through bacterial coupling can be applied to the industrial manufacture of fucosylated
oligosaccharides. Journal of Industrial Microbiology & Biotechnology (2000) 25, 213–217.
Received 01 May 2000/ Accepted in revised form 20 July 2000 相似文献
19.
Racanicchi L Montanucci P Basta GP Pensato A Conti V Calafiore R 《Molecular and cellular biochemistry》2008,308(1-2):17-24
Human promyelocytic leukemia HL-60 cells represent an in vitro model of acute promyelocytic leukemia (APL), and are inducible
to terminally differentiate into morphologically mature granulocytes by incubation with all trans retinoic acid (ATRA). Lysosomal
glycohydrolases are involved in the changes of the membrane surface proteins’ glycosylation, linked to the metastatic progression
potential of neoplastic cells. In particular, it has been demonstrated that the Asn-linked glucidic residues were directly
responsible for the metastatic potential, and it is known that the glycohydrolase α-d-mannosidase specifically hydrolyze the Asn-linked oligosaccharides. In this report, we present an in vitro study on the ATRA
effects on lysosomal glycohydrolases expression and the eventual relationship with the retinoic acid-induced differentiation
of HL-60 cells. We have investigated two highly expressed lysosomal glycohydrolases, namely β-d-hexosaminidase and α-d-mannosidase, and showed that they were differently affected by ATRA differentiating action. In particular, due to the specific
action on Asn-linked oligosaccharides, we tested α-d-mannosidase enzymatic activity and observed that it was dramatically decreased after ATRA incubation, indicating a relationship
with the differentiation state of the cells. These observations may directly be linked with the loss of metastatic progession
of differentiated HL-60. 相似文献