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1.
Valery Kudryashov Hyunjin M. Kim Govindaswami Ragupathi Samuel J. Danishefsky Philip O. Livingston K. O. Lloyd 《Cancer immunology, immunotherapy : CII》1998,45(6):281-286
Many human carcinomas overexpress the Lewisy (Ley) blood-group epitope [Fucα1→2Galβ1→4 (Fucα1→3)GlcNAcβ1→3Gal-]. With a view to developing Ley based vaccines we have examined the immunogenicity of Ley-protein conjugates in mice. Ley pentasaccharide was synthesized as its allyl glycoside and coupled to keyhole limpet hemocyanin (KLH) by reductive amination
or by a novel method utilizing a maleido-derivitized alkyl carboxyhydrazide as a bridging group to 2-iminothiolane-derivitized
KLH. Ley oligosaccharide was also coupled to bovine serum albumin by reductive amination. Immunization of groups of mice with the
three conjugates, together with the immunological adjuvant QS21, showed that Ley oligosaccharide directly coupled to KLH was the most efficient conjugate for eliciting IgG and IgM antibody responses to
naturally occurring forms of Ley epitopes carried on mucins and glycolipids. These antibodies were also reactive with and cytotoxic to a human breast cancer
cell line expressing Ley (MCF-7). These experiments suggest that Ley-KLH antigen and QS21 adjuvant could be considered as an immunogenic therapeutic vaccine in carcinoma patients.
Received: 28 March 1997 / Accepted: 2 September 1997 相似文献
2.
Immunogold labeling was used to study the distribution of (1 → 3)-β-glucans and (1 → 3, 1 → 4)-β-glucans in the rice grain
during cellularization of the endosperm. At approximately 3–5 d after pollination the syncytial endosperm is converted into
a cellular tissue by three developmentally distinct types of wall. The initial free-growing anticlinal walls, which compartmentalize
the syncytium into open-ended alveoli, are formed in the absence of mitosis and phragmoplasts. This stage is followed by unidirectional
(centripetal) growth of the anticlinal walls mediated by adventitious phragmoplasts that form between adjacent interphase
nuclei. Finally, the periclinal walls that divide the alveoli are formed in association with centripetally expanding interzonal
phragmoplasts following karyokinesis. The second and third types of wall are formed alternately until the endosperm is cellular
throughout. All three types of wall that cellularize the endosperm contain (1 → 3)-β-glucans but not (1 → 3, 1 → 4)-β-glucans,
whereas cell walls in the surrounding maternal tissues contain considerable amounts of (1 → 3, 1 → 4)-β-glucans with (1 → 3)-β-glucans
present only around plasmodesmata. The callosic endosperm walls remain thin and cell plate-like throughout the cellularization
process, appearing to exhibit a prolonged juvenile state.
Received: 7 January 1997 / Accepted: 11 February 1997 相似文献
3.
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
4.
Previous studies on the carbohydrate specificities of Erythrina cristagalli lectin (ECL) were mainly limited to analyzing the binding of oligo-antennary Galβ1→4GlcNAc (II). In this report, a wider range of recognition factors of ECL toward known mammalian ligands and glycans were examined by
enzyme-linked lectinosorbent and inhibition assays, using natural polyvalent glycotopes, and a glycan array assay. From the
results, it is shown that GalNAc was an active ligand, but its polyvalent structural units, in contrast to those of Gal, were
poor inhibitors. Among soluble natural glycans tested for 50% molecular mass inhibition, Streptococcus pneumoniae type 14 capsular polysaccharide of polyvalent II was the most potent inhibitor; it was 2.1 × 104, 3.9 × 103 and 2.4 × 103 more active than Gal, tri-antennary II and monomeric II, respectively. Most type II-containing glycoproteins were also potent inhibitors, indicating that special polyvalent II and Galβ1-related structures play critically important roles in lectin binding. Mapping all information available, it can
be concluded that: [a] Galβ1→4GlcNAc (II) and some Galβ1-related oligosaccharides, rather than GalNAc-related oligosaccharides, are the core structures for lectin
binding; [b] their polyvalent II forms within macromolecules are a potent recognition force for ECL, while II monomer and oligo-antennary II forms play only a limited role in binding; [c] the shape of the lectin binding domains may correspond to a cavity type with
Galβ1→4GlcNAc as the core binding site with additional one to four sugars subsites, and is most complementary to a linear
trisaccharide, Galβ1→4GlcNAcβ1→6Gal. These analyses should facilitate the understanding of the binding function of ECL.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
5.
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
6.
Ragupathi G Howard L Cappello S Koganty RR Qiu D Longenecker BM Reddish MA Lloyd KO Livingston PO 《Cancer immunology, immunotherapy : CII》1999,48(1):1-8
Sialyl-Tn (STn) is an O-serine- or O-threonine-linked disaccharide [NeuAcα(2→6)GalNAcα- O-Ser/Thr) expressed on mucins of most types of adenocarcinoma as single STn or clustered STn [STn (c)] epitopes. Though STn
is expressed on some normal tissues it is relatively tumor-specific, especially in the clustered conformation. Clinical trials
with STn-keyhole limpet hemocyanin (KLH) conjugate vaccines, prepared using reductive amination with a two-carbon linker group,
have resulted in high titers against STn but lower titers against natural forms of STn (ovine submaxillary mucin, or tumor
cells). To obtain antibodies of more appropriate specificity, we attempted to prepare STn(c)-KLH conjugates to establish their
immunogenicity in mice in preparation for clinical trials; however, conjugation efficiency was poor when the same two-carbon
linker was used, presumably because of steric hindrance. STn-KLH and STn(c)-KLH conjugates were prepared using the regular
two-carbon or the recently developed more efficient longer heterobifunctional 4-(4-maleimidomethyl)cyclohexane-1-carboxyl
hydrazide (MMCCH) linkers, and the resulting immunogenicities in mice were compared. The highest titers against STn were seen
with the STn-KLH conjugate with the two-carbon linker, and the highest titers against STn(c) were seen with STn(c)-KLH with
the MMCCH linker. Conjugation with MMCCH resulted in the highest conjugation efficiency (yield) and the highest titers against
ovine submaxillary mucin and STn-positive tumor cells, and is the method of choice for the preparation of STn(c) vaccine for
clinical trials.
Received: 30 October 1998 / Accepted: 18 December 1998 相似文献
7.
P. Livingston Shengle Zhang Sucharita Adluri Tzy-Jynn Yao Linda Graeber Govindaswami Ragupathi F. Helling Martin Fleisher 《Cancer immunology, immunotherapy : CII》1997,43(6):324-330
Natural IgM antibodies against the melanoma cell-surface ganglioside GM2, and IgM antibodies induced by vaccination with
GM2 adherent to bacillus Calmette-Guerin, have been correlated with increased disease-free and overall survival in melanoma
patients in previous phase I and II clinical trials. A vaccine containing GM2 covalently attached to keyhole limpet hemocyanin
(KLH) plus the immunological adjuvant QS-21 now induces higher-titer, longer-lasting IgM antibodies against GM2 and has recently
entered phase III clinical trials. For the first time this new vaccine also induces IgG antibodies against GM2 in the majority
of immunized patients. With regard to immunity against bacteria, IgM antibodies have been described to be 1000-fold more effective
than IgG antibodies at opsonification, complement-mediated cytotoxicity and protection from bacterial challenge. Though IgG
antibodies have the theoretical advantage of being able to mediate antibody-directed cell-mediated cytotoxicity (ADCC), they
may inhibit complement mediated IgM effector mechanisms against melanoma cells. Our goal was to confirm the functional characteristics
of the anti-GM2 IgM and IgG antibodies induced by vaccination and to determine the impact that IgG antibodies might have on
IgM antibody reactivity with GM2-positive tumor cells. Post-immunization sera from seven immunized patients were separated
by size-exclusion chromatography into IgM and IgG fractions and a variety of serological assays were performed with the individual
fractions and their combinations. Assays identifying specific IgM or IgG reactivity demonstrated partial inhibition by the
opposite fraction. However, when the endpoint was complement-mediated lysis or overall antibody binding, which may more faithfully
predict in vivo complement-mediated opsonification and lysis, the combinations of IgM and IgG fractions consistently demonstrated
higher reactivity than either fraction alone. In addition, ADCC was induced in all seven patients. The results were the same
whether the sera were obtained after 2 months or 2 years of immunizations. These findings suggest that IgG antibodies induced
by the GM2-KLH plus QS-21 vaccine will not inhibit and should further augment the clinical impact of induced IgM antibodies.
Received: 25 April 1996 / Accepted: 21 October 1996 相似文献
8.
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
9.
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
10.
Perico ME Mezzanzanica D Luison E Alberti P Panza L Russo G Canevari S 《Cancer immunology, immunotherapy : CII》2000,49(6):296-304
Aberrant glycosylation is one of the most constant traits of malignant cells. The CaMBr1 hexasaccharide antigen, originally
defined on the human breast carcinoma cell line MCF7, is expressed on some normal tissues but overexpressed in a high percentage
of human breast, ovary, prostate and lung carcinomas. CaMBr1 overexpression is associated with poor prognosis. The epitope
consists of the tetrasaccharide Fuc(α1-2)Gal(β1-3)GalNAc(β1-3)Galα-O-spacer, which has recently become available as a synthetic oligosaccharide. Here we report the CaMBr1 tetrasaccharide conjugation
to two different carrier proteins (CRM197 and KLH) and the evaluation of conjugate immunogenicity in mice following their
administration in various vaccine formulations with two adjuvants (MPL-SE and Detox-PC). Radioimmunoassay to determine the
level and isotype of anti-tetrasaccharide antibodies in mouse sera, and cytofluorimetric analysis and 51Cr-release assay on human tumor cells, to evaluate specificity of binding and complement-dependent lysis respectively, identified
CaMBr1-CRM197, in association with the MPL-SE adjuvant, as the best vaccine formulation. This combination induced (1) production
of tetrasaccharide-specific antibodies, with negligible side-effects; (2) antibodies with complement-mediated cytotoxic activity
on human CaMBr1-positive cells and (3) a high titer of IgG1 detected in sera obtained 3 months after the first injection,
indicating that the anti-tetrasaccharide antibody response was mediated by T cell activation. The availability of CaMBr1-glycoconjugate
in the minimal and functional antigenic structure and the identification of an efficacious vaccine formulation opens the way
to exploring the activity of this glycoconjugate in a clinical setting.
Received: 20 January 2000 / Accepted: 16 March 2000 相似文献
11.
Seven analogues of p-nitrophenyl T-antigen [Galβ(1→3)GalNAcα(1→O)PNP] have been synthesized as potential substrates for elucidation of the substrate specificity of endo-α-N-acetylgalactosaminidase. These compounds, which are commercially unavailable, include: GlcNAcβ(1→3){GlcNAcβ(1→6)}GalNAcα(1→O)PNP [core 4 type], GalNAcα(1→3)GalNAcα(1→O)PNP [core 5 type], GlcNAcβ(1→6)GalNAcα(1→O)PNP [core 6 type], GalNAcα(1→6)GalNAcα(1→O)PNP [core 7 type], Galα(1→3)GalNAcα(1→O)PNP [core 8 type], Glcβ(1→3)GalNAcα(1→O)PNP and GalNAcβ(1→3)GalNAcα(1→O)PNP. The assembly of these synthetic probes was accomplished efficiently, based on di-tert-butylsilylene(DTBS)-directed α-galactosylation as a key reaction. 相似文献
12.
13.
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
14.
Bretting H Messer M Bornaghi L Kröger L Mischnick P Thiem J 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2000,170(8):601-613
Adult snails synthesize in their albumen glands a polysaccharide which is composed exclusively of D- or D- and L-galactose
(Gal) residues which are interglycosidically linked by 1 → 3 and 1 → 6 bonds. It is the only carbohydrate source for embryos
and freshly hatched snails. Two galactosyltransferases are described in this study which are most likely involved in the biosynthesis
of this polysaccharide. One identified in Helix pomatia acts on oligosaccharides and could be used to synthesize a tetrasaccharide when the branched trisaccharide D-Gal-β-(1 → 3)-[D-Galβ-(1 → 6)]-D-Galβ-1 → OMe
was offered as acceptor. This enzyme, requiring Mg++- and Mn++-ions for activity, introduced a linear β-(1 → 6) linkage at the terminal non-reducing ends and was not detected in Biomphalaria glabrata. The other enzyme, which introduced β-(1 → 6) linkages at subterminal D-Gal residues, thus forming branching points in the
polysaccharide, was found in H. pomatia, Arianta arbustorum and B. glabrata with comparable activities. With the enzyme preparation of H. pomatia, up to four D-Gal residues were introduced into vicinal positions, forming single-membered side chains, if a hexasaccharide
with five linearly β-(1 → 3)-linked D-Gal residues was offered as a acceptor. The multiple-branched structure formed is typical
for snail galactans, making this enzyme a prime candidate for the branching enzyme in galactan synthesis. The enzyme activity
could be solubilized and purified by affinity chromatography. In SDS-polyacrylamide electrophoresis, the Helix- derived eluate displayed two bands (68, 37 kDa) and that of Biomphalaria five bands (68, 63, 17.5; 15; 13 kDa). The purified material showed only 8% of the total activity of the crude extracts,
but it could be shown that a phosphatase present in the crude extract can degrade UDP formed in the transfer reaction and
thus drive the reaction to completion.
Accepted: 23 August 2000 相似文献
15.
Genes controlling hydroxylations of phytosiderophores are located on different chromosomes in barley (Hordeum vulgare L.) 总被引:3,自引:0,他引:3
Jian Feng Ma Shin Taketa Yi-Chieh Chang Takashi Iwashita Hideaki Matsumoto Kazuyoshi Takeda Kyosuke Nomoto 《Planta》1999,207(4):590-596
Phytosiderophores, mugineic acids, have been demonstrated to be involved in Fe acquisition in gramineous plants. In this
study, chromosomal arm locations of genes encoding for biosynthesis of various phytosiderophores were identified in a cultivar
of barley (Hordeum vulgare L. cv. Betzes). Using wheat (Triticum aestivum L. cv. Chinese Spring)-barley (cv. Betzes) ditelosomic addition lines for 4HS and 4HL, a gene for hydroxylation of 2′-deoxymugineic
acid to mugineic acid was localized to the long arm of barley chromosome 4H. To locate the gene for hydroxylation of mugineic
acid to 3-epihydroxymugineic acid, hybrids between the 4H addition line and other wheat-barley addition lines were studied.
Only a hybrid between 4H and 7H addition lines produced 3-epihydroxymugineic acid. The gene was further localized to the long
arm of chromosome 7H by feeding mugineic acid to ditelosomic addition lines for 7HS and 7HL. A new phytosiderophore was discovered
in both 7H and 7HL addition lines, which was identified to be 3-epihydroxy-2′-deoxymugineic acid by detailed nuclear magnetic
resonance studies. These results revealed that in barley there are two pathways from 2′-deoxymugineic acid to 3-epihydroxymugineic
acid: 2′-deoxymugineic acid → mugineic acid → 3-epihydroxymugineic acid and 2′-deoxymugineic acid → 3-epihydroxy-2′-deoxymugineic
acid → 3-epihydroxymugineic acid. Barley genes encoding for the hydroxylations of phytosiderophores are located in different
chromosomes and each gene hydroxylates different C-positions: the long arm of chromosome 4H carries the gene for hydroxylating
the C-2′ position and the long arm of chromosome 7H carries the gene for hydroxylating the C-3 position of the azetidine ring.
Received: 10 August 1998 / Accepted: 30 September 1998 相似文献
16.
C. Lehmann B. Glass M. Zeis N. Schmitz L. Uharek 《Cancer immunology, immunotherapy : CII》1999,48(4):209-213
Activation of natural killer (NK) cells with interleukin-2 (IL-2) and IL-12 leads to an enhanced lysis of tumour cells. We
investigated the ability of NK cells, with or without prior activation, to lyse a variety of small-cell lung cancer (SCLC)
target cells. Specific lysis was measured with a fluorometric assay for NK-cell-mediated cytotoxicity: target cells were labelled
with 3,3′-dioctadecyloxacarbocyanine, a green membrane dye. After co-incubation with NK cells, dead target cells were stained
with propidium iodide, a red DNA dye that only penetrates dead cells. Of all eight SCLC cell lines tested, three were susceptible
to lysis by non-activated NK cells, three were only susceptible to lysis by NK cells activated with IL-2 and IL-12 and two
were not even susceptible to lysis by activated NK cells. The differences in target cell susceptibility showed no correlation
with the expression of MHC-I on the surface of the target cells or with the expression of the adhesion molecules CD50, CD54,
CD58 or CD102. Comparing the kinetics of the lysis of one SCLC cell line sensitive to non-activated NK cells and one sensitive
only to activated NK cells, we found that maximum lysis of the former was obtained after 1 h, whereas significant lysis of
the latter was only obtained after 4 h of incubation. This might be due to different mechanisms engaged in target cell lysis.
Received: 23 December 1998 / Accepted: 8 April 1999 相似文献
17.
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
18.
Jeschke U Karsten U Wiest I Schulze S Kuhn C Friese K Walzel H 《Histochemistry and cell biology》2006,126(4):437-444
Galectin-1 (gal-1), a member of the mammalian β-galactoside-binding proteins, recognizes preferentially Galβ1-4GlcNAc sequences of several cell surface oligosaccharides. We demonstrate histochemically that the lectin recognizes appropriate glycotopes on the syncytiotrophoblast and extravillous trophoblast layer from second trimester human placenta and on BeWo chorion carcinoma cells. Gal-1 binding to BeWo cells was diminished by the Thomsen–Friedreich (TF)-disaccharide (Galβ1-3GalNAc-) conjugated to polyacrylamide (TF–PAA). Gal-1 also inhibited BeWo cell proliferation in a concentration-dependent manner. Similar antiproliferative effects were also observed with an anti-TF monoclonal antibody (mAb, A78-G/A7). Therefore, we conclude that ligation of Galβ1-4GlcNAc and Galβ1-3GalNAc epitopes on BeWo cells may have regulatory effects on cell proliferation. 相似文献
19.
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
20.
Johannes Muthing 《Glycoconjugate journal》1997,14(2):241-248
The gangliosides GM1b, GalNAc-GM1b and GD1α are typical compounds of concanavalin A stimulated splenic T lymphoblasts of CBA/J
inbred mice. Their structural characterization has been described in previous studies. The intention of this work was the
comparative TLC immunostaining analysis of the glycosphingolipid composition of lectin stimulated splenic T lymphoblasts obtained
from six genetically different inbred mouse strains. The strains examined were AKR, BALB/c, C57BL/6, CBA/J, DBA/2 and WHT/Ht,
which are commonly used for biochemical and immunological studies. The neutral glycosphingolipid GgOse4Cer, the precursor
for GM1b-type gangliosides, was expressed by all six strains investigated. AKR, C57BL/6 and DBA/2 showed high and BALB/c,
CBA/J and WHT/Ht diminished expression in T lymphoblasts, based on single cell calculation. The gangliosides GM1b and GalNAc-GM1b,
elongation products of GgOse4Cer, displayed strain-specific differences in their intensities, which were found to correlate
with the intensities of GgOse4Cer expression of the same strains. Concerning sialic acid substitution of gangliosides, GM1b
and GalNAc-GM1b predominantly carry N-acetylneuraminic acid, whereas choleragenoid receptors GM1a and Gal-GalNAc-GM1b, which
are also expressed by all six strains, are characterized by dominance of N-glycolylneuraminic acid. Two highly polar gangliosides, designated with X and Y, which have not been previously recognized
in murine lymphoid tissue, were detected by positive anti-GalNAc-GM1b antibody and choleragenoid binding, respectively. Both
gangliosides were restricted to AKR, DBA/2 and C57BL/6 mice. The other three strains BALB/c, CBA/J and WHT/Ht are lacking
these structures. In summary, the GM1b-type pathway is quite active in all six strains analysed in this study. Strain-specific
genetic variations in T lymphoblast gangliosides were observed with the occurrence of gangliosides X and Y. This study and
data from other groups strongly indicate for GM1b-type gangliosides a functional association with T cell activation and leukocyte
mediated reactions. Abbreviations: ConA, concanavalin A; GSL(s), glycosphingolipid(s); HPTLC, high-performance thin-layer
chromatography; NeuAc, N-acetylneuraminic acid; NeuGc, N-glycolylneuraminic acid. The designation of the following glycosphingolipids
follows the IUPAC-IUB recommendations (1977) [48] and the ganglioside nomenclature system of Svennerholm [49] for GM1a-type
gangliosides. Glucosylceramide or GlcCer, Glcβ1-1Cer; lactosylceramide or LacCer, Galβ1-4Glcβ1-1Cer; gangliotriaosylceramide
or GgOse3Cer or Gg3, GalNAcβ1-4Galβ1-4Glcβ1-1Cer; gangliotetraosylceramide or GgOse4Cer or Gg4, Galβ1-3GalNAcβ1-4Galβ1-4Glcβ1-1Cer;
gangliopentaosylceramide or GgOse5Cer, GalNAcβ1-4Galβ1-3GalNAcβ1-4Galβ1-4Glcβ1-1Cer; gangliohexaosylceramide or GgOse6Cer,
Galβ1-3GalNAcβ1-4Galβ1-3GalNAcβ1-4Galβ1-4Glcβ1-1Cer. GM3, II3NeuAc-LacCer; GM1 or GM1a, II3NeuAc-GgOse4Cer; GM1b, IV3NeuAc-GgOse4Cer;
GalNAc-GM1b, IV3NeuAc-GgOse5Cer; GD1a, IV3NeuAc, II3NeuAc-GgOse4Cer; GD1b, II3(NeuAc)2-GgOse4Cer; GD1c, IV3(NeuAc)2-GgOse4Cer;
GD1α, IV3NeuAc, III6NeuAc-GgOse4Cer. Only NeuAc-substituted gangliosides are presented in this list of abbreviations
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献