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1.
《Bioscience, biotechnology, and biochemistry》2013,77(7):1272-1275
The allergenicity of a Kunitz-type soybean trypsin inhibitor (KSTI) was investigated by a micro-assay of β-N-acetylhexosaminidase released from RBL-2H3 cells primed with the anti-KSTI serum. KSTI stimulated the release of β-N-acetylhexosaminidase from RBL-2H3 cells primed with the antiserum. The response of RBL-2H3 cells to the reaginic activity of the mouse anti-KSTI serum correlates fairly well with that by the passive cutaneous anaphylaxis (PCA) test, the sensitivity of both assays appearing to be similar. These results suggest that measuring the β-N-acetylhexosaminidase released from RBL-2H3 is a convenient way for studying the allergen or the reaginic activity of a murine serum in place of the PCA test. 相似文献
2.
T. J. Budd C. D. Dolman A. M. Lawson W. Chai J. Saxton F. W. Hemming 《Glycoconjugate journal》1992,9(5):274-278
N-Acetylneuraminic acid (Neu5Ac) andN-glycoloylneuraminic acid (Neu5Gc) are distributed widely in nature. Using a Carbopac PA-1 anion exchange column, we have determined the ratios of Neu5Ac and Neu5Gc in hydrolysates of platelets and their precursors: a rat promegakaryoblastic (RPM) cell line and a human megakaryoblastic leukemia cell line (MEG-01). The ratio of Neu5Gc:Neu5Ac in cultured RPM cells is 16:1, whereas in platelet rich plasma and cultured MEG-01 cells it is 1:38 and 1:28, respectively. The nature of these sialic acids from RPM cells was verified using thin layer chromatography and liquid secondary ion mass spectrometry. The relevance of increased Neu5Gc levels in early stages of development is discussed.Abbreviations Neu5Ac
N-acetylneuraminic acid
- Neu5Gc
N-glycoloylneuraminic acid
- RPM
rat promegakaryoblast
- MEG-01
human megakaryoblastic leukaemia cell line
- PAD
pulsed amperometric detection
- WGA
wheat germ agglutinin
- FCS
foetal calf serum
- PPEADF
phosphatidylethanolamine dipalmitoyl
- LSIMS
liquid secondary ion mass spectrometry
- HPAEC
high performance anion exchange chromatography
- TBA
thiobarbituric acid 相似文献
3.
Lawrence SM Huddleston KA Tomiya N Nguyen N Lee YC Vann WF Coleman TA Betenbaugh MJ 《Glycoconjugate journal》2001,18(3):205-213
The addition of sialic acid residues to glycoproteins can affect important protein properties including biological activity and in vivo circulatory half-life. For sialylation to occur, the donor sugar nucleotide cytidine monophospho-sialic acid (CMP-SA) must be generated and enzymatically transferred to an acceptor oligosaccharide. However, examination of insect cells grown in serum-free medium revealed negligible native levels of the most common sialic acid nucleotide, CMP-N-acetylneuraminic acid (CMP-Neu5Ac). To increase substrate levels, the enzymes of the metabolic pathway for CMP-SA synthesis have been engineered into insect cells using the baculovirus expression system. In this study, a human CMP-sialic acid synthase cDNA was identified and found to encode a protein with 94% identity to the murine homologue. The human CMP-sialic acid synthase (Cmp-Sas) is ubiquitously expressed in human cells from multiple tissues. When expressed in insect cells using the baculovirus vector, the encoded protein is functional and localizes to the nucleus as in mammalian cells. In addition, co-expression of Cmp-Sas with the recently cloned sialic acid phosphate synthase with N-acetylmannosamine feeding yields intracellular CMP-Neu5Ac levels 30 times higher than those observed in unsupplemented CHO cells. The absence of any one of these three components abolishes CMP-Neu5Ac production in vivo. However, when N-acetylmannosamine feeding is omitted, the sugar nucleotide form of deaminated Neu5Ac, CMP-2-keto-3-deoxy-D-glycero-D-galacto-nononic acid (CMP-KDN), is produced instead, indicating that alternative sialic acid glycoforms may eventually be possible in insect cells. The human CMP-SAS enzyme is also capable of CMP-N-glycolylneuraminic acid (CMP-Neu5Gc) synthesis when provided with the proper substrate. Engineering the CMP-SA metabolic pathway may be beneficial in various cell lines in which CMP-Neu5Ac production limits sialylation of glycoproteins or other glycans. 相似文献
4.
The dominant glycosylation mutants of MDAY-D2 mouse lymphoma cells, designated class 2 (D33W25 and D34W25) were selected for their resistance to the toxic effects of wheat germ agglutinin (WGA) and shown to express elevated levels of Neu5Gc. In accordance with this, the activity of CMP-Neu5Ac hydroxylase was found to be substantially higher in the mutant cells. The hydroxylase in the D33W25 mutant cells exhibited kinetic properties identical to those of the same enzyme from mouse liver. Growth rate experimentsin vivo andin vitro, where the mutant cells grew more slowly at low cell densities in serum-free medium and also formed slower growing tumours in syngeneic mice, indicate that CMP-Neu5Ac hydroxylase expression may be associated with altered growth of the mutant cells.Abbreviations WGA
wheat germ agglutinin
- Neu5Ac
N-acetyl--d-neuraminic acid
- Neu5Gc
N-glycology--d-neuraminic acid
- CMP-Neu5Ac
cytidine-5-monophospho-N-acetylneuraminic acid
- CMP-Neu5Gc
cytidine-5-monophospho-N-glycoloylneuraminic acid
- FACS
fluorescence-activated cell sorting
- buffer A
triethylamine hydrogen carbonate, pH 7.6 (concentration given at appropriate points in the text)
- SFM
serum free medium
- IMDM
Iscove's modified Dulbecco's medium
- CMP-Neu5Ac hydroxylase
CMP-N-acetylneuraminate: NAD(P)H oxido-reductase (N-acetyl hydroxylating) (EC 1.14.99.18); CMP-sialate hydrolase (EC 3.1.4.40); sialic acid-pyruvate lyase (EC 4.1.3.3) 相似文献
5.
Dopamine--hydroxylase has been purified from human serum. The amino acid composition has been determined and found to be similar to that of the enzyme purified from human pheochromocytoma. Human serum dopamine--hydroxylase is a glycoprotein, containing 13.11 g carbohydrates/100 g protein. Individual sugar determinations showed the presence of fucose, galactose, glucose, mannose,N-acetylglucosamine,N-acetylgalactosamine andN-acetylneuraminic acid. 相似文献
6.
G. Bugla-Płoskońska A. Kiersnowski B. Futoma-Kołoch W. Doroszkiewicz 《Microbial ecology》2009,58(2):276-289
Serum is an environment in which bacterial cells should not exist. The serum complement system provides innate defense against
microbial infections. It consists of at least 35 proteins, mostly in pre-activated enzymatic forms. The activation of complement
is achieved through three major pathways: the classical, alternative, and lectin. Lysozyme, widely present in body fluids,
catalyzes the hydrolysis of β 1,4 linkage between N-acetyloglucosamine and N-acetylmuramic acid in the bacterial cell wall and cooperates with the complement system in the bactericidal action of serum.
In this study, ten strains of serotype O48 Salmonella, mainly associated with warm-blooded vertebrates and clinically important causing diarrhea in infants and children, were
tested. The results demonstrated that the most efficient killing of Salmonella O48 occurred when all the components of normal bovine serum (NBS) and normal human serum (NHS) cooperated. To prove the role
of lysozyme in the bactericidal activity of bovine and human serum, the method of serum adsorption onto bentonite (montmorillonite,
MMT) was used. In order to investigate structural transitions accompanying the adsorption of serum components, we applied
X-ray diffraction methods. The results of this investigation suggested that apart from lysozyme, other proteins (as, e.g.,
C3 protein or IgG immunoglobulin) were adsorbed on MMT particles. It was also shown that Ca2+ cations can be adsorbed on bentonite. This may explain the different sensitivities of the serovars belonging to the same
O48 Salmonella serotype to NBS and NHS devoid of lysozyme. 相似文献
7.
Panayotis A. Siskos Maria-Helen E. Spyridaki 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1999,724(2):346
A simple, rapid and sensitive reversed-phase ion-pair high-performance liquid chromatographic method for the determination of N-acetylneuraminic acid and 2-deoxy-2,3-dehydro-N-acetylneuraminic acid in biological fluids is described. Determination of N-acetylneuraminic acid released by acidic hydrolysis, in serum, urine and saliva, and 2-deoxy-2,3-dehydro-N-acetylneuraminic acid in urine, without hydrolysis, was accomplished by injecting the sample without derivatization, into the chromatograph. Measurements were carried out isocratically within 6 min using a C18 column and a mobile phase of aqueous solution of triisopropanolamine, as ion-pair reagent, 60 mM, pH 3.5 at room temperature with UV absorbance detection. The present method is reported for the first time for the determination of sialic acids in biological fluids. Recoveries in serum, urine and saliva ranged from 90 to 102% and the limits of detection were 60 nM and 20 nM for the two sialic acids, respectively. The method has been applied to normal and pathological sera from patients with breast, stomach, colon, ovarian and cervix cancers, to normal urine and urine from patient with sialuria and to normal saliva. 相似文献
8.
Junya Mitoma Tatsuo Miyazaki Mark Sutton-Smith Misa Suzuki Hideo Saito Jiunn-Chern Yeh Takehiro Kawano Ole Hindsgaul Peter H. Seeberger Maria Panico Stuart M. Haslam Howard R. Morris Richard D. Cummings Anne Dell Minoru Fukuda 《Glycoconjugate journal》2009,26(5):511-523
E-, P- and L-selectins critically function in lymphocyte recirculation and recruiting leukocytes to inflammatory sites. MECA-79
antibody inhibits L-selectin-mediated lymphocyte adhesion in several species and does not require sialic acid in its epitope.
Many other antibodies, however, recognize human selectin ligands expressing N-acetylneuraminic acid but not mouse selectin ligands expressing N-glycolylneuraminic acid, suggesting that difference in sialic acid in sialyl Lewis X leads to differential reactivity. We
found that HECA-452 and FH6 monoclonal antibodies bind Chinese hamster ovary (CHO) cells expressing N-acetylneuraminyl Lewis X oligosaccharide but not its N-glycolyl form. Moreover, synthetic N-acetylneuraminyl Lewis X oligosaccharide but not its N-glycolyl oligosaccharide inhibited HECA-452 and FH6 binding. By contrast, E-, P- and L-selectin bound to CHO cells regardless
of whether they express N-acetyl or N-glycolyl form of sialyl Lewis X, showing that selectins have a broader recognition capacity than HECA-452 and FH-6 anti-sialyl
Lewis x antibodies.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
9.
Vitamin D-binding protein (DBP) and albumin (ALB) are abundant serum proteins and both possess high-affinity binding for saturated and unsaturated fatty acids. However, certain differences exist. We surmised that in cases where serum albumin level is low, DBP presumably can act as a transporter of fatty acids. To explore this possibility we synthesized several alkylating derivatives of 14C-palmitic acid to probe the fatty acid-binding pockets of DBP and ALB. We observed that N-ethyl-5-phenylisooxazolium-3′-sulfonate-ester (WRK-ester) of 14C-palmitic acid specifically labeled DBP; but p-nitrophenyl- and N-hydroxysuccinimidyl-esters failed to do so. However, p-nitrophenyl ester of 14C-palmitic acid specifically labeled bovine ALB, indicating that the micro-environment of the fatty acid-binding domains of DBP and ALB may be different; and DBP may not replace ALB as a transporter of fatty acids. 相似文献
10.
Lieke T Gröbe D Blanchard V Grunow D Tauber R Zimmermann-Kordmann M Jacobs T Reutter W 《Glycoconjugate journal》2011,28(1):31-37
The etiologic agent of Chagas’ disease, Trypanosoma cruzi, is widely distributed in South America, affecting millions of people with thousands of deaths every year. Adherence of the
infectious trypomastigote to host cells is mediated by sialic acid. T. cruzi cannot synthesize sialic acids on their own but cleave them from the host cells and link them to glycans on the surface of
the parasites using the trans-sialidase, a GPI-anchored enzyme. The infectivity of the protozoan parasites strongly depends
on the activity of this enzyme. In this report, we investigated whether the transfer of sialic acids from the host to the
parasites can be attenuated using novel sialic acid precursors. The cell line 86-HG-39 was infected with T. cruzi and treated with defined N-acylmannosamine analogues bearing an elongated N-acyl side-chain. By treatment of these cells the number of T.cruzi infected cell was reduced up to 60%. We also showed that the activity of the bacterial sialidase C was reduced with N-glycan
substrates with elongated N-acyl side chains of the terminal sialic acids. The affinity of this sialidase decreased with the length of the N-acyl side-chain. The data presented suggest that N-acyl modified sialic acid precursors can change the transfer of sialic acids leading to modification of infection. Since
the chemotherapy of this disease is inefficient and afflicted by side effects, the need of effective drugs is lasting. These
findings propose a new path to prevent the dissemination of T. cruzi in the human hosts. These compounds or further modified analogues might be a basis for the search of new agents against Chagas’
disease. 相似文献
11.
《Redox report : communications in free radical research》2013,18(1):13-22
AbstractThere is concern that dental-resin materials directly loaded on a prepared tooth adversely affect dental pulp tissue by releasing the resin chemicals through dentinal tubes. This study determined whether self-curing polymethyl methacrylate (PMMA)-based dental resin extract adversely affected the viability and function of odontoblast-like cells and whether the cytotoxicity of this resin, if any, could be eliminated by N-acetyl cysteine, an antioxidant amino acid derivative. Odontoblast-like cells isolated from rat maxillary incisor dental pulp tissue were exposed to a PMMA resin extract with or without N-acetyl cysteine for 1 h and then cultured in osteoblastic media. The percentage of viable cells 24 h after seeding was 20% in cells exposed to the resin extract without N-acetyl cysteine, whereas 45% of cells were viable after exposure to the N-acetyl cysteine-supplemented extract. The cells that had been exposed to the extract showed a strong tendency for apoptosis associated with the increased reactive oxygen species production and decreased intracellular glutathione level, which was improved by the addition of N-acetyl cysteine. N-Acetyl cysteine supplementation almost completely restored the significantly reduced alkaline phosphatase activity and matrix mineralization by the resin extract. These results conclusively demonstrated that exposure of odontoblast-like cells to the resin extract impaired the cell viability and function and, more intriguingly, N-acetyl cysteine supplementation to the extract significantly prevented these toxic effects. 相似文献
12.
Gerd Reuter Roland Schauer Reginaldo Prioli Miercio E A Pereira 《Glycoconjugate journal》1987,4(4):339-348
In the culture supernatant ofTrypanosoma rangeli, strain El Salvador, a sialidase was present with an activity of 0.1 U/mg protein as determined with the 4-methylumbelliferyl glycoside of -N-acetylneuraminic acid as substrate. This enzyme was purified about 700-fold almost to homogeneity by gel chromatography on Sephadex G-100 and Blue Sepharose, and affinity chromatographies on 2-deoxy-2,3-didehydroneuraminic acid and horse submandibular gland mucin, both immobilized on Sepharose. The pH optimum is at 5.4–5.6, and the molecular weight was determined by gel chromatography, high performance liquid chromatography and sodium dodecyl sulphate gel electrophoresis to be 70 000. The substrate specificity of the enzyme is comparable to bacterial, viral and mammalian sialidases with cleavage rates for the following substrates in decreasing order:
N-acetylneuraminyl-(2–3)-lactose>
N-glycoloylneuraminy-(2–3)-lactose>
N-acetylneuraminyl-(2–6)-lactose >sialoglycoproteins>gangliosides>9-O-acetylated sialoglycoproteins.4-O-Acetylated derivatives are resistant towards the action of this sialidase. The enzyme activity can be inhibited by 2-deoxy-2,3-didehydro-N-acetylneuraminic acid, Hg2+ ions, andp-nitrophenyloxamic acid; it is not dependent on the presence of Ca2+ Mn2+ or Mg2+ ions.Abbreviations BSA
bovine serum albumin
- BSM
bovine submandibular gland mucin
- CMP
cytidine monophosphate
- EDIA
ethylenediaminetetraacetic acid
- ESM
equine submandibular gland mucin
- HEPES
N-2-hydroxyethylpiperazine-N-2-ethanesulfonic acid
- HPLC
high performance liquid chromatography
- Lac
lactose
- MU-Neu5Ac
4-methylumbelliferyl glycoside of -N-acetylneuraminic acid
- Neu5Ac
N-acetylneuraminic acid
- Neu5Ac2en
2-deoxy-2,3-didehydro-N-acetylneuraminic acid
- Neu4Ac5Gc
N-glycoloyl-4-O-acetylneuraminic acid
- Neu2en
2-deoxy-2,3-didehydroneuraminic acid
- Neu5Gc
N-glycoloylneuraminic acid
- PMSF
phenylmethylsulfonyl fluoride
- PSM
pig submandibular gland mucin
- SDS
sodium dodecyl sulfate
- Tris
tris-(hydroxymethyl)aminomethane
Dedicated to Professor Dr. Heinz Mühlpfordt on the occasion of his 65th birthday. 相似文献
13.
Margaret V. Merritt Silvia S. Sid Ludmila Mesh Mary M. Allen 《Archives of microbiology》1994,162(3):158-166
Gas chromatography-mass spectrometry studies of the nitrogen isotopic composition of the N-trifluoroacetyl n-butyl ester derivatives of the amino acids from isolated hydrolyzed cyanophycin from 15N-enriched cells led to two major findings: (1) the amino acid composition of this granular polypeptide, isolated using procedures optimized for extracting and purifying cyanophycin from cells in the stationary growth phase, varied with the culture growth condition; (2) the rate of incorporation of exogenous nitrate differed for each nitrogen atom of the amino acid constituents of cyanophycin or cyanophycin-like polypeptide. Arginine and aspartic acid were the principle components of cyanophycin isolated from exponentially growing cells and from light-limited stationary phase cells, with glutamic acid as an additional minor component. The cyanophycin-like polypeptide from nitrogen-limited cells contained only aspartic and glutamic acids, but no arginine. The glutamic acid content decreased and arginine content increased as nitrate was provided to nitrogen-limited cells. These cells rapidly incorporated nitrate at different rates at each cyanophycin nitrogen site: guanidino nitrogens of arginine>aspartic acid >-amino nitrogen of arginine>glutamic acid. Little media-derived nitrogen was incorporated into cyanophycin of exponentially growing cells during one cellular doubling time.Abbreviations
asp-TAB, glu-TAB, arg-TAB
N-Trifluoroacetyl n-butyl ester derivatives of aspartic acid, glutamic acid and arginine, respectively
-
CAP
chloramphenicol
-
CF
correction factor
-
TFAA
Trifluoroacetic anhydride
-
MBTFA
N-Methyl-bis-trifluoroacetamide 相似文献
14.
Robert J. Bonney Joyce E. Becker P. Roy Walker R. Van Potter 《In vitro cellular & developmental biology. Plant》1974,9(6):399-413
Summary Parenchymal cells from adult rat liver which had been fully regenerated were isolated and cultured in nonproliferating monolayers
in vitro. The optimum conditions for attachment of these cells to Falcon plastic dishes were determined. When approximately
1.0×105 nuclei per cm2 suspended in Ham's F-12 medium with 0.5 μg of insulin per ml and 25% fetal calf serum were incubated at 37°C for 24 hr, about
50% became attached and contiguous. When the above medium was supplemented with synthetic buffers 2-(N-morpholino) ethanesulfonic acid (MES) andN-tris (hydroxymethyl) methyl-2-aminoethanesulfonic acid (TES), the presence of 15% fetal calf serum also allowed an attachement
effiency of 50%. Tyrosine aminotrasferase activity in the cells was elevated when the culture medium was supplemented with
hydrocortisone or dexamethasone. The largest increases were observed after 72 hr of culture. Cycloheximide prevented the increase.
Presented in part at the 24th Annual Meeting of the Tissue Culture Association, Boston, Mass. June 4 to 7, 1973.
The work was supported in part by National Cancer Institute Grants CA-51304-01 (R. J. B.) and CA-07175. P. R. W. was a Damon
Runyon Memorial Fund Postdoctoral Fellow. 相似文献
15.
Gary R. Burleson Charles F. Kulpa Haydn E. Edwards J. Kerry Thomas 《Experimental cell research》1978,116(2):291-300
The fluorescent probes pyrene, pyrene butyric acid and N-phenyl 1-naphthylamine were used to study membranes of normal cells, RSV-transformed cells, cells treated with a proteolytic enzyme, and cells persistently infected with lymphocytic choriomeningitis virus. The lifetimes of excited pyrene and pyrene butyric acid showed only minor changes when these probes were in normal, transformed, trypsinized or persistently infected cells. However, pyrene, but not pyrene butyric acid, lifetimes are shorter in cell membranes than in homogeneous solvents. The quenching of excited pyrene in cells by quencher molecules was slower than corresponding reactions in homogeneous solutions indicating that the probe was screened from the quenchers by the membrane. However, quenching reactions with the pyrene butyric acid probe were similar in cells and homogeneous solvents. This indicates that pyrene and pyrene butyric acid reside in different lipid regions of the membrane. Transformed and trypsinized cells showed increased membrane fluidity compared to normal and persistently infected cells. Membrane fluidity was determined from the excimer/monomer fluorescence ratios of pyrene, and by the polarization of N-phenyl 1-naphthylamine fluorescence. Several techniques distinguished between normal and transformed or trypsinized cells; however, the only parameter unique to viral transformation was a blue shift of the fluorescence maxima of N-phenyl 1-naphthylamine. This shift reflected a less polar environment for N-phenyl 1-naphthylamine in virus-transformed cells. 相似文献
16.
Epidermal growth factor stimulates DNA-synthesis of astrocytes in primary cerebellar cultures 总被引:9,自引:0,他引:9
Summary The capability of epidermal growth factor (EGF) to stimulate DNA synthesis in neural cells was investigated in primary cultures of early postnatal mouse cerebellum. At concentrations of 10-8M, EGF stimulates DNA synthesis in astrocytes, which were identified immunocytologically by the cell type-specific marker, glial fibrillary acidic (GFA) protein. Astrocytes express cell-surface receptors for EGF as can be shown by binding of [125I]-labeled EGF to live monolayer cultures. In the presence of 10% horse serum, EGF stimulates DNA-synthesis by a factor of about two-fold. Stimulation by EGF over control values is approximately 4-fold in the presence of 1% serum and 6 to 10-fold in the absence of serum. Absolute numbers of astrocytes are increased after more prolonged action of EGF. DNA-synthesis in neurons or oligodendroglia is not significantly stimulated by EGF. EGF enhances cell survival of serum-deprived cerebellar cultures. Fibroblast growth factor does not increase DNA-synthesis in astrocytes under the conditions used in this study.Abbreviations
BME
basal medium, Eagle's
-
BME-BSA
basal medium, Eagle's containing 0.1% bovine serum albumin
-
EDTA
ethylene-diamino-N, N-tetraacetic acid
-
EGF
epidermal growth factor
-
FGF
fibroblast growth factor
-
GFA
glial fibrillary acidic
-
HS
horse serum
- [3
H] TdR
tritium-labeled thymidine
-
PAP
peroxidase-anti-peroxidase
-
PBS
phosphate-buffered saline
-
SDS
sodium dodecyl sulfate
-
TCA
trichloroacetic acid 相似文献
17.
The long held but challenged view that plants do not synthesize sialic acids was re-evaluated using two different procedures to isolate putative sialic acid containing material from plant tissues and cells. The extracts were reacted with 1,2-diamino-4,5-methylene dioxybenzene and the fluorescently labelled 2-keto sugar acids analysed by reversed phase and normal phase HPLC and by HPLC–electrospray tandem mass spectrometry. No N-glycolylneuraminic acid was found in the protein fraction from Arabidopsis thaliana MM2d cells. However, we did detect 3-deoxy-d-manno-octulosonic acid and trace amounts (3–18 pmol/g fresh weight) of a compound indistinguishable from N-acetylneuraminic acid by its retention time and its mass spectral fragmentation pattern. Thus, plant cells and tissues contain five orders of magnitude less sialic acid than mammalian tissues such as porcine liver. Similar or lower amounts of N-acetylneuraminic acid were detected in tobacco cells, mung bean sprouts, apple and banana. Yet even yeast and buffer blanks, when subjected to the same isolation procedures, apparently contained the equivalent of 5 pmol of sialic acid per gram of material. Thus, we conclude that it is not possible to demonstrate unequivocally that plants synthesize sialic acids because the amounts of these sugars detected in plant cells and tissues are so small that they may originate from extraneous contaminants. 相似文献
18.
Siiri Hirmo Sørge Kelm Roland Schauer Bo Nilsson Torkel Wadström 《Glycoconjugate journal》1996,13(6):1005-1011
Helicobacter pylori is a human pathogen associated with gastritis and peptic ulcer. Adhesion properties ofH. pylori to various structures have been described in the literature, including evidence for sialic acid-binding. To study the specificity and frequency of sialic acid-binding, fourteenH. pylori strains were investigated using haemagglutination with derivatized erythrocytes carrying sialic acids only on defined glycans and using haemagglutination inhibition assays. From these studiesH. pylori strains can be grouped into sialic acid-dependent and sialic acid-independent classes. The sialic acid-dependent strains require -2,3-linked sialic acid for haemagglutination. The potential roles of sialic acid-dependent adhesions forH. pylori-related infections are discussed.Abbreviations Sia
sialic acids
- Neu5Ac
N-acetyl-neuraminic acid
- Neu5Gc
N-glycolylneuraminic acid
- Neu5Fm
N-formylneuraminic acid
- Neu5TFA
N-trifluoroacetylneuraminic acid
- RBC
human red blood cells (erythrocytes) 相似文献
19.
J. F. Madrid M. T. Castells J. A. Martínez-Menárguez M. Avilés F. Hernández J. Ballesta 《Histochemistry and cell biology》1994,101(3):195-204
Gallbladder mucus is mainly composed of glycoproteins, which seem to play a critical role in cholesterol nucleation during gallstone formation. The biosynthetic pathway and sequential processing as well as the characterization of the oligosaccharide sidechains of human gallbladder secretory glycoproteins have not been completely defined. The aim of the present study is the subcellular characterization of the glycoproteins in the principal cells of human gallbladder. Principal cells of normal human gallbladder were studied by means of a variety of cytochemical techniques, including lectin histochemistry, enzyme and chemical treatments, immunocytochemistry and lectin-gold technology. Fucose, galactose, N-acetylglucosamine, N-acetylgalactosamine and N-acetylneuraminic acid residues were detected in mucous granules, Golgi apparatus and apical membrane of principal cells. Mannose residues were only observed in dense bodies. Oligosaccharide side-chains of the glycoproteins contained in the biliary mucus are synthesized in the Golgi apparatus of the principal cells of the gallbladder epithelium and are also contained in the mucous granules of these cells. Terminal N-acetylneuraminic acid(2-3)galactose(1-3)N-acetylgalactosamine, N-acetylneuraminic acid(2-3)galactose(1-4)N-acetylglucosamine and galactose(1-4)N-acetylglucosamine sequences are contained in the oligosaccharide chains of gallbladder mucus glycoproteins. The dense bodies detected in the cytoplasm of the principal cells contained N-linked glycoproteins. Mucin-type O-linked glycoproteins were the main components of the mucous granules although some N-linked chains were also detected. 相似文献
20.
Summary The level of tubulin in cultured matureZinnia mesophyll cells increases to between 4 and 5 times its initial value when DNA synthesis occurs. The rapid increase in the level of tubulin requires the presence of auxin and cytokinin, as does the induction of DNA synthesis. Inhibitors of DNA synthesis suppress the rapid increase in the level of tubulin. These results imply that the rapid increase in the level of tubulin is dependent on the occurrence of DNA synthesis,i.e., on the reinitiation of the cell cycle. The presence of microtubules is not important for either the increase in the level of tubulin or for the induction of DNA synthesis, because both the increase in the level of tubulin and DNA synthesis occur even when microtubules are depolymerized by colchicine.Abbreviations APM
amiprophos-methyl
- araC
arabinosylcytosine
- BA
6-benzyladenine
- BSA
bovine serum albumin
- DMSO
dimethylsulfoxide
- EGTA
ethylene glycol bis(2-aminoethylether)tetraacetic acid
- FITC
fluorescein isothiocyanate
- FUdR
fluorodeoxyuridine
- GA
gibberellin A3
- IAA
indole-3-acetic acid
- MES
2-(N-morpholino)ethanesulfonic acid
- NAA
1-naphthaleneacetic acid
- PBS
phosphate buffered saline
- PCA
perchloric acid
- PIPES
piperazine-N,N-bis(2-ethanesulfonic acid)
- SDS
sodium dodecyl sulfate 相似文献