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1.
Hisashi Ashida Hayato Ozawa Kiyotaka Fujita Shun’ichi Suzuki Kenji Yamamoto 《Glycoconjugate journal》2010,27(1):125-132
Endo-α-N-acetylgalactosaminidase catalyzes the release of Galβ1-3GalNAc from the core 1-type O-glycan (Galβ1-3GalNAcα1-Ser/Thr) of mucin glycoproteins and synthetic p-nitrophenyl (pNP) α-linked substrates. Here, we report the enzymatic syntheses of core 1 disaccharide-containing glycopeptides using the
transglycosylation activity of endo-α-N-acetylgalactosaminidase (EngBF) from Bifidobacterium longum. The enzyme directly transferred Galβ1-3GalNAc to serine or threonine residues of bioactive peptides such as PAMP-12, bradykinin,
peptide-T and MUC1a when Galβ1-3GalNAcα1-pNP was used as a donor substrate. The enzyme was also found to catalyze the reverse-hydrolysis reaction. EngBF synthesized
the core 1 disaccharide-containing oligosaccharides when the enzyme was incubated with either glucose or lactose and Galβ1-3GalNAc
prepared from porcine gastric mucin using bifidobacterial cells expressing endo-α-N-acetylgalactosaminidase. Synthesized oligosaccharides are promising prebiotics for bifidobacteria. 相似文献
2.
To elucidate the mechanism underlying the hydrolysis of the GalNAcβ1→4Gal linkage in ganglioside GM2 [GalNAcβ1→4(NeuAcα2→3)Galβ1→4Glcβ1→1′
Cer] by β-hexosaminidase A (Hex A) with GM2 activator protein, we designed and synthesized two kinds of GM2 linkage analogues—6′-NeuAc-GM2
and α-GalNAc-GM2. In this paper, the efficient and systematic synthesis of these GM2 analogues was described. The highlight
of our synthesis process is that the key intermediates, newly developed sialyllactose derivatives, were efficiently prepared
in sufficient quantities; these derivatives directly served as highly reactive glycosyl acceptors and coupled with GalNTroc
donors to furnish the assembly of GM2 tetrasaccharides in large quantities. 相似文献
3.
To clarify the structure of non-sialic acid anionic residue on N-glycans in the mammalian tissues, we have isolated sialidase-resistant
anionic residue on N-glycans from bovine lung. Analyses by partial acid hydrolysis and glycosidase digestions combined with
a two-dimensional HPLC mapping method revealed that the major sialidase-resistant anionic N-glycan had a fucosylbianntenary
core structure. The anionic residue was identified as a sulfate ester by methanolysis, anion-exchange chromatography, and
mass spectrometry. The linkage position of the sulfate ester was the 6-position of the GlcNAc residue on the Manα1-6 branch.
This conclusion was based on the results of glycosidase digestions followed by two-dimensional HPLC mapping. Furthermore,
the disialylated form of this sulfated glycan was dominant, and no asialo form was detected. The structure of the major anionic
N-glycan prepared from bovine lung and having a sulfate was proposed to be the pyridylamino derivative of Siaα2-3Gαlβ1-4(HSO3-6)GlcNAcβ1-2Manα1-6(Siaα2-3Galβ1-4GlcNAcβ1-2Manα1-3)Manβ1-4GlcNAcβ1-4(Fucα1-6)GlcNAc. 相似文献
4.
Daisei Miyamoto Takao Ueno Sachiko Takashima Kazuhide Ohta Toshio Miyawaki Takashi Suzuki Yasuo Suzuki 《Glycoconjugate journal》1997,14(3):379-388
A new monoclonal antibody (TU-1) directed against the Galα1-4Galβ1-4Glc residue of the Gb3Cer/CD77 antigen was prepared by
the hybridoma technique following immunization of mice with an emulsion composed of monophosphoryl lipid A, trehalose dimycolate,
and Gb3Cer isolated from porcine erythrocytes. TU-1 showed reactivity towards Gb3Cer and lyso-Gb3Cer (Galα1-4Galβ1-4Glcβ1-1′Sph),
although the reactivity towards lyso-Gb3Cer was about 10-fold lower than that to Gb3Cer. But it did not react with other structurally-related
glycolipids, such as LacCer (Galβ1-4Glcβ1-1′Cer), Gg3Cer, Gg4Cer, Gb4Cer (GalNAcβ1-3Galα1-4Galβ1-4Glcβ1-1′Cer), galactosylparagloboside
(Galα1-3Galβ1-4GlcNAcβ1-3Galβ1-4Glcβ1-1′Cer), sulfatide (HSO3-3Galβ1-1′Cer), other gangliosides (GM3, GM2, GM1a, GD1a and
GT1b), or P1 antigen (Galα1-4Galβ1-4GlcNAcβ1-3Galβ1-4Glcβ1-1′Cer) among neutral glycolipids prepared from P1 phenotype red
blood cells. Furthermore, TU-1 reacted with viable lymphoma cells, such as human Burkitt lymphoma cell line, Daudi, and Epstein-Barr
virus (EBV)-transformed B cells by the immunofluorescence method, and also with germinal centre B cells in human tonsil and
vessel endothelial cells in human thymus histochemically. These results indicate that TU-1 is a monoclonal antibody directed
against Gb3Cer/CD77 antigen and can be utilized as a diagnostic reagent for Burkitt's lymphoma and also for detection of the
blood group Pk antigen in glycolipid extracts of erythrocytes. Abbreviations: ATL, adult T-cell leukaemia; BSA, bovine serum
albumin; Cer, ceramide; DPPC, L-α-dipalmitoylphosphatidylcholine; EBV, Epstein-Barr virus; FCS, fetal calf serum; GalCer,
Galβ1-1′Cer; GlcCer, Glcβ1-1′Cer; LacCer, Galβ1-4Glcβ1-1′Cer; Gb3Cer, Galα1-4Galβ1-4Glcβ1-1′Cer; Iyso-Gb3Cer, Galα1-4Galβ1-4Glc1-1′Sph;
Gb4Cer, GalNAcβ1-3Galα1-4Galβ1-4Glc1-1′Cer; galactosylparagloboside, Galα1-3Galβ1-4GlcNAcβ1-3Galβ1-4Glcβ1-1′Cer; Gg3Cer, GalNAcβ1-4Galβ1-4Glcβ1-1′Cer;
Gg4Cer, Galβ1-3GalNAcβ1-4Galβ1-4Glcβ1-1′Cer; GM3, Neu5Acα2-3Galβ1-4Glcβ1-1′Cer; GM2, GalNAcβ1-4(Neu5Acα2-3) Galβ1-4Glcβ1-1′Cer;
GM1a, Galβ1-3GalNAcβ1-4(Neu5Acα2-3)Galβ1-4Glcβ1-1′Cer; GD1a, Neu5Acα2-3Galβ1-3GalNAcβ1-4(Neu5Acα2-3)Galβ1-4Glcβ1-1′Cer; GD1b,
Galβ1-3GalNAcβ1-4(Neu5Acα2-8Neu5Acα2-3)Galβ1-4Glcβ1-1′Cer; GT1b, Neu5Acα2-3Galβ1-3GalNAcβ1-4(Neu5Acα2-8Neu5Acα2-3) Galβ1-4Glcβ1-1′Cer;
HRP, horseradish peroxidase; LDH, lactate dehydrogenase; MAb, monoclonal antibody; MPL, monophosphoryl lipid A; P1 antigen,
Galα1-4Galβ1-4GlcNAcβ1-3Galβ1-4Glcβ1-1′Cer; PVP, polyvinylpyrolidone; Sph, sphingosine; sulfatide, HSO3-Galβ1-1′Cer; TDM,
trehalose dimycolate; TLC, thin-layer chromatography
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献
5.
Eugenia M. Rapoport Ekaterina V. Moiseeva Dmitry A. Aronov Sergey V. Khaidukov Galina V. Pazynina Svetlana V. Tsygankova Ivan M. Ryzhov Ivan M. Belyanchikov Tatiana V. Tyrtysh Kenneth C. McCullough Nicolai V. Bovin 《Glycoconjugate journal》2020,37(1):129-138
Modification of vaccine carriers by decoration with glycans can enhance binding to and even targeting of dendritic cells (DCs), thus augmenting vaccine efficacy. To find a specific glycan-“vector” it is necessary to know glycan-binding profile of DCs. This task is not trivial; the small number of circulating blood DCs available for isolation hinders screening and therefore advancement of the profiling. It would be more convenient to employ long-term cell cultures or even primary DCs from murine blood. We therefore examined whether THP-1 (human monocyte cell line) and DC2.4 (immature murine DC-like cell line) could serve as a model for human DCs. These cells were probed with a set of glycans previously identified as binding to circulating human CD14low/-CD16+CD83+ DCs. In addition, we tested a subpopulation of murine CD14low/-CD80+СD11c+CD16+ cells reported as relating to the human CD14low/-CD16+CD83+ cells. Manα1–3(Manα1–6)Manβ1–4GlcNAcβ1–4GlcNAcβ bound to both the cell lines and the murine CD14low/-CD80+СD11c+CD16+ cells. Primary cells, but not the cell cultures, were capable of binding GalNAcα1–3Galβ (Adi), the most potent ligand for binding to human circulating DCs. In conclusion, not one of the studied cell lines proved an adequate model for DCs processes involving lectin binding. Although the glycan-binding profile of BYRB-Rb (8.17)1Iem mouse DCs could prove useful for assessing human DCs, important glycan interactions were missing, a situation which was aggravated when employing cells from the BALB/c strain. Accordingly, one must treat results from murine work with caution when seeking vaccine targeting of human DCs, and certainly should avoid cell lines such as THP-1 and DC2.4 cells. 相似文献
6.
H. Kobayashi Hiroko Oyamada Naoko Iwadate Hiromi Suzuki Hideko Mitobe Kaori Takahashi Nobuyuki Shibata Shigeo Suzuki Yoshio Okawa 《Archives of microbiology》1998,169(3):188-194
A mannan of Candida glabrata IFO 0622 digested by Arthrobacter exo-α-mannosidase and a β-1,2-linked mannobiose obtained from the parent mannan by acid treatment was analyzed using 13C nuclear magnetic resonance spectroscopy. The results show that the β-1,2-linked mannobiosyl residue is esterified to a phosphate
group through position C-1 in the α-configuration, Manβ1– 2Manα1–HPO3–. The results of immunochemical assays of these mannans using the commercial antigenic factor sera of the genus Candida (Candida Check, Iatron) indicate that the main recognition site of serum no. 6 in this kit is the mannotetraosyl side-chain
Manβ1–2Manα1– 2Manα1–2Man in C. glabrata mannan and also suggest that the phosphate-containing unit (such as Manβ1– 2Manα1–HPO3– in this mannan) behaves as one of the antigenic determinants of serum no. 6, but not of serum no. 5. Therefore, the present
and previous findings indicate that serum no. 5 recognizes relatively longer β-1,2-linked oligomannosyl side-chains, Manβ1–[2Manβ1–]n 2Man (n = 1–6), attached to the phosphate groups previously observed in the cell wall mannans of Candida albicans, Candida stellatoidea, and Candida tropicalis.
Received: 18 March 1997 / Accepted: 16 September 1997 相似文献
7.
A chemical synthesis of uridine 5’-diphospho-N-acetyllactosamine (Galβ(1→4)GlcNAc-UDP; UDP-LacNAc) and Galβ(1→3)GlcNAc-UDP is described. Coupling of the disaccharide imidate
derivatives with dibenzylphosphate gave the corresponding 1-phosphates, which were condensed with UMP-imidazolate to give
the target UDP-oligosaccharides after purification by anion exchange HPLC and gel filtration column chromatography. Using
this methodology a variety of oligosaccharide nucleotide analogues can be synthesized. These UDP-oligosaccharides may be useful
for finding so-called `oligosaccharide transferases’, the glycosyltransferases which transfer the oligosaccharide moiety onto
glycosyl acceptors. 相似文献
8.
The ergot alkaloids elymoclavine, ergometrine and chanoclavine were α-mannosylated with α-mannosidase as catalyst. The kinetic
reaction with p-nitrophenyl α-mannoside as glycosyl donor gave ca 28 % yield of chanoclavine α-mannoside, whereas the equilibrium
reaction with mannose as the glycosyl donor gave ca 11 % yield. However, in the case of elymoclavine and ergometrine, higher
yields of α-mannosides were obtained with the equilibrium approach (18 and 13 %). 相似文献
9.
Novel oligosaccharide has suppressive activity against human leukemia cell proliferation 总被引:1,自引:0,他引:1
Hosomi O Misawa Y Takeya A Matahira Y Sugahara K Kubohara Y Yamakura F Kudo S 《Glycoconjugate journal》2009,26(2):189-198
Various oligosaccharides containing galactose(s) and one glucosamine (or N-acetylglucosamine) residues with β1–4, α1–6 and β1–6 glycosidic bond were synthesized; Galβ1–4GlcNH2, Galα1–6GlcNH2, Galα1–6GlcNAc, Galβ1–6GlcNH2, Galβ1–4Galβ1–4GlcNH2 and Galβ1–4Galβ1–4GlcNAc. Galα1–6GlcNH2 (MelNH2) and glucosamine (GlcNH2) had a suppressive effect on the proliferation of K562 cells, but none of the other saccharides tested containing GlcNAc
showed this effect. On the other hand, the proliferation of the human normal umbilical cord fibroblast was suppressed by none
of the saccharides other than GlcNH2. Adding Galα1–6GlcNH2 or glucosamine to the culture of K562 cell, the cell number decreased strikingly after 72 h. Staining the remaining cells
with Cellstain Hoechst 33258, chromatin aggregation was found in many cells, indicating the occurrence of cell death. Furthermore,
all of the cells were stained with Galα1–6GlcNH-FITC (MelNH-FITC). Neither the control cells nor the cells incubated with
glucosamine were stained. On the other hand, when GlcNH-FITC was also added to cell cultures, some of them incubated with
Galα1–6GlcNH2 were stained. The difference in the stainability of the K562 cells by Galα1–6GlcNH-FITC and GlcNH-FITC suggests that the
intake of Galα1–6GlcNH2 and the cell death induced by this saccharide is not same as those of glucosamine. The isolation of the Galα1–6GlcNH2 binding protein was performed by affinity chromatography (melibiose-agarose) and LC-MS/MS, and we identified the human heterogeneous
ribonucleoprotein (hnRNP) A1 (34.3 kDa) isoform protein (30.8 kDa). The hnRNP A1 protein was also detected from the eluate(s)
of the MelNH-agarose column by the immunological method (anti-hnRNP-A1 and HRP-labeled anti-mouse IgG (γ) antibodies). 相似文献
10.
Peter R. Andreana Przemyslaw Kowal Adam J. Janczuk Peng George Wang 《Glycoconjugate journal》2003,20(2):107-118
Galactose oxidase (EC 1.1.3.9, GAO) was used to convert the C-6′ OH of Galβ(1 → 4)Glcβ–OBn (5) to the corresponding hydrated
aldehyde (7). Chemical modification, through dehydratative coupling and reductive amination, gave rise to a small library
of Galβ(1 → 4)Glcβ–OBn analogues (9a–f, 10, 11). UDP-[6-3H]Gal studies indicated that α1,3-galactosyltransferase recognized the C-6′ modified Galβ(1 → 4)Glcβ–OBn analogues (9a–f,
10, 11). Preparative scale reactions ensued, utilizing a single enzyme UDP-Gal conversion as well as a dual enzymatic system
(GalE and α1,3GalT), taking full advantage of the more economical UDP-Glc, giving rise to compounds 6, 15–22. Galα(1 → 3)Galβ(1
→ 4)Glcβ–OBn trisaccharide (6) was produced on a large scale (2 g) and subjected to the same chemoenzymatic modification as
stated above to produce C-6″ modified derivatives (23–30). An ELISA bioassay was performed utilizing human anti-αGal antibodies
to study the binding affinity of the derivatized epitopes (6, 15–30). Modifications made at the C-6′ position did not alter
the IgG antibody's ability to recognize the unnatural epitopes. Modifications made at the C-6″ position resulted in significant
or complete abrogation of recognition. The results indicate that the C-6′ OH of the αGal trisaccharide epitope is not mandatory
for antibody recognition. Published in 2004.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
11.
Sialyltrisaccharides based on β-galactosyldisaccharides were synthesized using β-galactosidase andtrans-sialidase in one pot. Using β-galactosidase fromBacillus circulans andtrans-sialidase fromTrypanosoma cruzi simultaneously, 6 mM sialyltrisaccharides composed of about 95% NeuAcα(2,3)Galβ(1,4)GlcNAc and 5% NeuAcα(2,3)Galβ(1,6)GlcNAc
were produced from a reaction mixture containing 25 mM 0-nitrophenyl-β-D-galactopyranoside, 100 mM N-acety lglucosamine and
10 mM p-nitrophenyl-α-D-N-acetylneuraminic acid. One beauty of this reaction was that a secondary hydrolysis of the disaccharide
intermediate occurring between the activated galactopyranoside and N-acetylglucosamine was prevented. Using β-galactosidase
fromEscherichia coli and the sametrans-sialidase, 15 mM sialyltrisaccharides composed of about 90% NeuAcα(2,3)Galβ(1,6)GlcNAc and 10% NeuAcα(2,3)Galβ (1,4)GlcNAc
were produced from a reaction mixture containing 400 mM galactose, 800 mM N-acetylglucosamine and 20 mMp-nitrophenyl-α-D-N-acetylneuraminic acid. In this study, the reverse-galactosylation reaction between galactose and N-acetylglucosamine
was dominant since the disaccharide intermediate mainly resulted in the sialylated product. 相似文献
12.
Rare polyagglutinable NOR erythrocytes contain unusual globoside extention products terminating with a Galα1-4GalNAcβ1-3Gal-
unit. This trisaccharide epitope is recognized by recently characterized antibodies naturally occurring in most human sera
(Duk et al., Glycobiology, 15, 109, 2005). These antibodies represent two major types of fine specificity. All these antibodies are most strongly inhibited by Galα1-4GalNAcβ1-3Gal
(NOR-tri), and weakly by Galα1-4Gal. However, the type 1 antibodies are strongly inhibited by Galα1-4Galβ1-3Gal-R and weakly
by Galα1-4GalNAc, while the type 2 antibodies show the opposite reactivities with these two oligosaccharides. Similar antibodies
have now been found in horse, rabbit and pig sera. The antibodies were purified from animal sera by affinity chromatography
on Galα1-4GalNAcβ1-3Gal-human serum albumin(HSA)-Sepharose 4B conjugate. The specificity of the antibodies was determined
by binding to ELISA plates coated with several α-galactosylated oligosaccharide-polyacrylamide (PAA) or -HSA conjugates and
by inhibition with synthetic oligosaccharides. The purified antibodies bound specifically to conjugates containing NOR-tri.
The inhibition of binding showed that the animal sera also contain two types of anti-NOR antibodies: type 2 was found in the
horse serum, and a mixture of both types was present in rabbit and pig serum. These results indicate that anti-NOR, a new
and distinct kind of anti-αGal antibody, are present in animal sera and show similar specificties and diversity as their counterparts
found in human sera. 相似文献
13.
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
14.
Stephen Henry Per-Ake Jovall Sohbat Ghardashkhani Anders Elmgren Tommy Martinsson Goran Larson Bo Samuelsson 《Glycoconjugate journal》1997,14(2):209-223
Total nonacid glycosphingolipids were isolated from small intestine mucosal scrapings of a red cell blood group O Le(a-b-)
nonsecretor cadaver. Glycolipids were extracted and fractionated into five fractions based on chromatographic and immunostaining
properties. These glycolipid fractions were then analysed by thin-layer chromatography for Lewis activity with antibodies
reactive to the type 1 precursor (Lec), H type 1 (Led), Lea and Leb epitopes. Fractions were structurally characterized by
mass spectrometry (EI-MS and EI-MS/MS-TOF) and proton NMR spectroscopy. EI-MS/MS-TOF allowed for the identification of trace
substances in fractions containing several other glycolipid species. Consistent with the red cell phenotype, large amounts
of lactotetraosylceramide (Lec-4) were detected. Inconsistent with the red cell phenotype, small quantities of Lea-5, H-5-1
and Leb-6 glycolipids were immunochemically and structurally identified in the small intestine of this individual. By EI-MS/MS-TOF
several large glycolipids with 9 and 10 sugar residues were also identified. The extensive carbohydrate chain elongation seen
in this individual with a Lewis negative nonsecretor phenotype supports the concept that Lewis and Secretor blood group fucosylation
may be a mechanism to control type 1 glycoconjugate chain extension. Abbreviations: FUT1, H gene; FUT2, Secretor gene, (gene
bank accession no. U17894); FUT3, Lewis gene or Fuc-TIII gene, (gene bank accession no. X53578); FUT5, Fuc-TV gene; [Imm]+,
immonium ion; Lea-5, Galβ1-3(Fucα1-4)GlcNAcβ1-3Galβ1-4Glcβ1-1Cer; Leb-6, Fucα1-2Galβ1-3(Fucα1-4)GlcNAcβ1-3Galβ1-4Glcβ1-1Cer;
Lec-4, Galβ1-3GlcNAcβ1-3Galβ1-4Glcβ1-1Cer; Led or H-5-1, Fucα1-2Galβ1-3GlcNAcβ1-3Galβ1-4Glcβ1-1Cer; Lex-5, Galβ1-4(Fucα1-3)GlcNAcβ1-3Galβ1-4Glcβ1-1Cer;
MAb, monoclonal antibody; MS, mass spectrometry; CID, collision-induced dissociation; EI, electron impact ionisation; MS/MS-TOF,
tandem mass spectrometry using a time-of-flight mass spectrometer as the second mass spectrometer: m/Cz, mass-to-charge ratio;
NMR, nuclear magnetic resonance; PCR, polymerase chain reaction; RFLP, restriction fragment length polymorphism; TLC, (high
performance) thin layer chromatography. Saccharide types are abbreviated to Hex for hexose, HexNAc for N-acetylhexosamine
and dHex for deoxyhexose (fucose). Ceramide is abbreviated to Cer, and ceramide types are abbreviated to d for dihydroxy and
t for trihydroxy base, n for non-hydroxy and h for hydroxy fatty acids
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献
15.
Perspectives on the significance of altered glycosylation of glycoproteins in cancer 总被引:13,自引:0,他引:13
No abstract Abbreviations: Sia, sialic acid, type unspecified; Tn antigen, GalNAcα 1-O-Ser/Thr; T antigen, Galβ1-3GalNAcα-O-Ser/Thr;
Sialyl LewisX, Siaα2-3Galβ1-4(Fucα1-3)GlcNAc; Sialyl Lewisa, Siaα2-3Galβ1-3(Fucα1-4)GlcNAc; Sialyl-Tn antigen, Siaα2-6GalNAcα1-O-Ser/Thr;
FucT, fucosyltransferase; ST, sialyltransferase.
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献
16.
Kerstin Lidholt Maria Fjelstad Ulf Lindahl Fumitaka Goto Tomoya Ogawa Hiroshi Kitagawa Kazuyuki Sugahara 《Glycoconjugate journal》1997,14(6):737-742
Two glycosaminoglycan-protein linkage tetrasaccharide-serine compounds, GlcAβ1-3Galβ1-3Galβ1-4Xylβ1-O-Ser and GlcAβ1-3Gal(4-O-sulfate)β1-3Galβ1-4Xylβ1-O-Ser,
were tested as hexosamine acceptors, using UDP-[3H]GlcNAc and UDP-[3H]GalNAc as sugar donors, and solubilized mouse mastocytoma
microsomes as enzyme source. The nonsulfated Ser-tetrasaccharide was found to function as an acceptor for a GalNAc residue,
whereas the Ser-tetrasaccharide containing a sulfated galactose unit was inactive. Characterization of the radio-labelled
product by digestion with α-N-acetylgalactosaminidase and β-N-acetylhexosaminidase revealed that the [3H]GalNAc unit was α-linked,
as in the product previously synthesized using serum enzymes, and not β-linked as found in the chondroitin sulfate polymer.
Heparan sulfate/heparin biosynthesis could not be primed by either of the two linkage Ser-tetrasaccharides, since no transfer
of [3H]GlcNAc from UDP-[3H]GlcNAc could be detected. By contrast, transfer of a [3H]GlcNAc unit to a [GlcAβ1-4GlcNAcα1-4]2-GlcAβ1-4-aMan
hexasaccharide acceptor used to assay the GlcNAc transferase involved in chain elongation, was readily detected. These results
are in agreement with the recent proposal that two different N-acetylglucosaminyl transferases catalyse the biosynthesis of
heparan sulfate. Although the mastocytoma system contains both the heparan sulfate/heparin and chondroitin sulfate biosynthetic
enzymes the Ser-tetrasaccharides do not seem to fulfil the requirements to serve as acceptors for the first HexNAc transfer
reactions involved in the formation of these polysaccharides.
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献
17.
Matrix-assisted laser desorption/ionization quadrupole ion trap time-of-flight mass spectrometry (MALDI-QIT-TOF MS) was used
to analyze three pyridylamino (PA)-fucosyloligosaccharides isolated from human milk: lacto-N-fucopentaose (LNFP) I [Fucα1-2Galβ1-3GlcNAcβ1-3Galβ1-4Glc-PA],
LNFP II [Galβ1-3(Fucα1-4)GlcNAcβ1-3Galβ1-4Glc-PA], and LNFP III [Galβ1-4(Fucα1-3)GlcNAcβ1-3Galβ1-4Glc-PA]. These oligosaccharides
are linkage isomers. MALDI-QIT-TOF MS provides MSn spectra, which we used to characterize these PA-oligosaccharides. MS/MS/MS analysis of the non-reducing end tri-saccharide
ions generated by MS/MS was able to distinguish these oligosaccharide isomers. The MALDI-QIT-TOF MS is a very convenient and
rapid method, therefore, it would be useful for high throughput structural analyses of various types of pyridylaminated oligosaccharide
isomers. 相似文献
18.
Yingxia Tan Feng Gong Subo Li Shouping Ji Yanping Lu Hongwei Gao Hua Xu Yangpei Zhang 《Glycoconjugate journal》2010,27(4):427-433
It has been reported that: (1) large variations were found in the number of sialic acid (SA) capped with N-acetyllactosamines (SA-Galβ1-4GlcNAc-R) and α-Gal epitopes (Galα1-3Galβ1-4GlcNAc-R) or uncapped N-acetyllactosamines (Galβ1-4GlcNAc-R) on different mammalian red blood cells, and on nucleated cells originating from a given
tissue in various species; (2) goat, sheep, horse and mouse red blood cells lack α-Gal epitopes, despite the expression of
this epitope on a variety of nucleated cells in these species, including lymphocytes differentiated from the same hematopoietic
origin. In this study, flow cytometry and Western blot analyses of pig red blood cells showed that α-Gal epitopes on pig red
cells developed concomitantly after treatment with neuraminidase, suggesting that the terminal N-acetyllactosaminide glycans were capped with SA-α-Gal epitopes. Whereas, the expression of the α-Gal epitopes on red blood
cells from Sika deer (Cevus nippon hortulorum) were found to be absent even though the epitopes were present on their white blood cells. Thus, these results add new data
not only for the terminal carbohydrate structures on cell surface glycans of various mammalian cells, but also for wide variety
of epitope expression on the cells from different tissues, which might be useful for understanding their unique states resulting
from differentiation and evolution. 相似文献
19.
Profiling of carbohydrate structures on cell membranes has been difficult to perform because of the complexity and the variations
of such structures on cell surface glycans. This study presents a novel method for rapid profiling of cell surface glycans
for terminal N-acetyllactosamines (Galβ1-(3)4GlcNAc-R) that are uncapped, capped with sialic acid as SA-Galβ1-(3)4GlcNAc-R, or with α1,3galactosyls
as the α-gal epitope- Galα1-3Galβ1-(3)4GlcNAc-R. This method includes two enzymatic reactions: (1) Terminal sialic acid is
removed by neuraminidase, and (2) α-gal epitopes are synthesized on the exposed N-acetyllactosamines by α1,3galactosyltransferase. Existing and de novo synthesized α-gal epitopes on cells are quantified by a modification of radioimmunoassay designated as “ELISA inhibition
assay,” which measures binding of the monoclonal anti-Gal antibody M86 to α-gal epitopes. This binding is proportional to
the number of cell surface α-gal epitopes. The amount of free M86 antibody molecules remaining in the solution is determined
by ELISA using synthetic α-gal epitopes linked to albumin as solid phase antigen. The number of α-gal epitopes on cells is
estimated by comparing binding curves of M86 incubated with the assayed cells, at various concentrations of the cells, with
the binding of M86 to rabbit red cells expressing 2 × 106 α-gal epitopes/cell. We could demonstrate large variations in the number of sialic acid capped N-acetyllactosamines, α-gal epitopes and uncapped N-acetyllactosamines on different mammalian red blood cells, and on nucleated cells originating from a given tissue in various
species. This method may be useful for rapid identification of changes in glycosylation patterns in cells subjected to various
treatments, or in various states of differentiation. 相似文献
20.
G. Ya. Wiederschain O. Koul N. V. Bovin N. E. Nifant’ev R. McCluer 《Russian Journal of Bioorganic Chemistry》2000,26(6):403-406
The substrate specificity of fucosyltransferase (FT) from rat forebrain and cerebellum was studied using synthetic acceptors.
Of 16 acceptors tested, only those containing the Galβ1-4GlcNAcβ1-R fragment were subjected to enzymic fucosylation. The isomer
with a 1–3 bond as well as lactose and oligosaccharides with an additional Neu5Ac residue attached to Gal or a Fuc residue
attached to GlcNAc were not fucosylated, whereas Fucα1-2Galβ1-4GlcNAc displayed the same substrate properties as Galβ1-4GlcNAc.
FT from the cerebellum and forebrain was shown to have a specificity similar to that of mammalian FT IV. The activity of the
cerebellum FT with all types of substrates was higher than that of FT isolated from the forebrain, the specificity profiles
being similar.
This communication is dedicated to the 70th birthday of Prof. A.Ya. Khorlin. 相似文献