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1.
Kentaro Horikawa Masahiko Yamasaki Masao Iwamori Hideki Nakakuma Kiyoshi Takatsuki Yoshitaka Nagai 《Glycoconjugate journal》1991,8(4):354-360
We analysed the glycolipids of mouse thymocytes before and after Concanavalin A (Con A) or recombinant interleukin-2 (rIL-2) stimulation by TLC-immunostaining with carbohydrate-specific antiglycolipid antibodies. The thymocytes were cultured in serum-free medium in the presence of 500 ng ml–1 Con A, 10 U ml–1 rIL-2 or Con A plus rIL-2 for 6, 12, 24, 48, and 72 h, and were found to start proliferating 24 h after cultivation in the presence of Con A or Con A plus rIL-2, the maximum levels being reached at 72 h and 48 h, respectively, in a thymidine uptake experiment. The concentrations of II3Neu-Gg4Cer, Gg4Cer and IV3GalNAc-Gb4Cer after 48 h Con A stimulation were found to be at almost the original levels. Conversely, II3Neu-Gg3Cer, which was not detected in the thymocytes at the start, began to appear after 48 h stimulation with Con A and Con A plus rIL-2, and IV3Neu-Gg5Cer in the cells 48 h after stimulation with Con A and Con A plus rIL-2 has increased to 41 and 44 times higher than in the original cells, respectively, as judged on TLC-immunostaining with monoclonal antibody YHD-06, which detects the GalNAc1-4(NeuAc or NeuGc2-3)Gal-structure. These results indicate that the increased synthesis of both gangliosides, in other words, the activation ofN-acetylgalactosaminyltransferase, is associated with the mitogen-induced proliferation.N-Acetylneuraminic acid was the sole sialic acid in II3Neu-Gg3Cer which newly appeared in the cells on stimulation, whereas the sialic acid of IV3Neu-Gg5Cer was a mixture ofN-acetyl- andN-glycoloylneuraminic acids. This result may suggest that the substrates for the two differentN-acetylgalactosaminyltransferases must be different. This GalNAc1-4(NeuAc or NeuGc2-3)Gal-structure was also detected on the surface of the Con A or Con A plus rIL-2 stimulated mouse thymocytes on flow cytometric analysis of cells indirectly stained with monoclonal antibody YHD-06.
Abbreviations: carbohydrate and glycolipid nomenclature and abbreviations follow the IUPAC-IUB recommendations or the nomenclature system of Svennerholm L. (1963)J Neurochem
10:613–23. 相似文献
2.
The fibronectin fragment VTHPGY and the corresponding glycopeptides V(Gal3GalNAc)THPGY and V(Gal3GalNAc)THPGY were synthesized by the FMOC/solid phase approach. FMOC derivatives of threonine, carrying O-linked, peracetylated Gal3GalNAc chains were used for introduction (HOBt-mediated coupling) of the disaccharide moieties.Abbreviations FMOC
9-fluorenylmethyloxycarbonyl
- DMTST
dimethyl(thiomethyl)sulfonium triflate
- DMF
dimethylformamide
- BOC
butoxycarbonal 相似文献
3.
《Biochimica et Biophysica Acta (BBA)/Lipids and Lipid Metabolism》1985,833(2):196-202
The metabolic fate of the bile add analogs, 3α,7α-dihydroxy-7β-methyl-5β-cholanoic acid and 3α,7β-dihydroxy-7α-methyl-5β-cholanoic acid, was investigated and compared with that of chenodeoxycholic acid in hamsters. Both bile acid analogs were absorbed rapidly from the intestine and excreted into bile at similar to that of chenodeoxycholic acid. In the strain of hamster studied, the biliary bile were conjugated with both glycine and taurine. After continuous intravenous infusion, chenodeoxycholic acid the analogs became the major bile acid constituents in bile. After oral administration of a single dose of these compounds, fecal analysis revealed the existence of unchanged material (25–35%) as well as considerable amounts of metabolites (65–75%). The major metabolites excreted into feces were more polar than the starting material and were tentatively identified as trifaydroxy-7-methyl compounds by radioactive thin-layer chromatography. However, monohydroxy compounds were also found in the fecal extracts. These results show that chenodeoxycholic acid and ursodeoxycholic acid with a methyl group at the 7-position are resistant to bacterial 7-dehydroxylation than the normally occurring bile acids and that a certain proportion of these analogs is hydroxylated to give the corespondiag trihydroxy compound(s), In a control experiment, about 5% of administered chenodeoxychoulic acid was metabolized to a trihydroxy feile acid, but most of the compound (95%) was transformed into lithocholic acid. 相似文献
4.
By the conventional methods of gas liquid chromatography (GLC) as well as mass spectrometry, 3β,7α-dihydroxychol-5-en-24-oic acid (Δ5-acid), a key intermediate of chenodeoxycholic acid biogenesis and its metabolic by-product, 3α,7α-dihydroxychol-4-en-24-oic acid (Δ4-acid) have not yet been identified as such probably due to thermal decomposition. However, taking advantage of the observation that they are readily methoxylated in methanoi containing a trace of acids, their individual methoxy-compounds were easily prepared and proved to be useful for their identification, even though they are present in minimal amounts as was the case with the human or hen bile. The present paper reported physical as well as spectral properties of the methoxy-compounds derived from methyl 3α,7α-dihydroxychol-4-en-24-oate, compared with those of its 3β-epimer 相似文献
5.
M. V. Bogachek B. N. Zaitsev S. K. Sekatskii E. V. Protopopova V. A. Ternovoi A. V. Ivanova A. V. Kachko V. A. Ivanisenko G. Dietler V. B. Loktev 《Biochemistry. Biokhimii?a》2010,75(4):472-480
Recombinant polypeptide containing the 260–466 amino acid sequence of West Nile virus (WNV) strain LEIV-Vlg99-27889-human
glycoprotein E (gpE, E260–466) was constructed. Immunochemical similarity between the E260–466 and gpE of WNV was proven by enzyme immunoassay (EIA), immunoblot, competitive EIA, hemagglutination inhibition, and neutralization
tests using polyclonal and monoclonal antibodies against the viral gpE and recombinant E260–466. Polypeptide E260–466 induced formation of virus neutralizing and cross-reactive antibodies that were interactive with various epitopes of this
recombinant protein. It is shown by evaluation of the interaction of E260–466 with one of the proposed cell receptors of WNV that average E260–466-αVβ3 integrin-specific interaction force measured using atomic force spectroscopy was 80 and 140 pN for single and double
interactions, correspondingly. Taken together with previously described interaction between laminin-binding protein (LBP)
and WNV gpE domain II, it is proposed that WNV gpE can interact specifically with two cellular proteins (LBP and αVβ3 integrin)
during virus entry. 相似文献
6.
Kurt G. I. Nilsson 《Biotechnology letters》1996,18(7):791-794
A new approach for the highly specific preparation of L-serine conjugates of lactosamine and Gal1-3GalNAc is described. Thus, the L-serine derivative of lactosamine Gal1-4GlcNAc-O-(N-Z)-Ser-OEt, was obtained from lactose, employing GlcNAc-O-(N-Z)-Ser-OEt as acceptor and a yeast -galactosidase as catalyst Galp 1-3GalNAc-O-(N-Alloc)-Ser-OMe was obtained from lactose, employing GalNAc-O-(N-Alloc)-Ser-OMe as acceptor and -galactosidase from bovine testes as catalyst. 相似文献
7.
William Kuhns Volker Rutz Hans Paulsen Khushi L. Matta Michael A. Baker Marijke Barner Maria Granovsky Inka Brockhausen 《Glycoconjugate journal》1993,10(5):381-394
To elucidate control mechanisms ofO-glycan biosynthesis in leukemia and to develop biosynthetic inhibitors we have characterized core 2 UDP-GlcNAc:Gal1-3GalNAc-R(GlcNAc to GalNAc) 6-N-acetylglucosaminyl-transferase (EC 2.4.1.102; core 2 6-GlcNAc-T) and CMP-sialic acid: Gal1-3GalNAc-R 3-sialyltransferase (EC 2.4.99.4; 3-SA-T), two enzymes that are significantly increased in patients with chronic myelogenous leukemia (CML) and acute myeloid leukemia (AML). We observed distinct tissue-specific kinetic differences for the core 2 6-GlcNAc-T activity; core 2 6-GlcNAc-T from mucin secreting tissue (named core 2 6-GlcNAc-T M) is accompanied by activities that synthesize core 4 [GlcNAc1-6(GlcNAc1-3)GalNAc-R] and blood group I [GlcNAc1-6(GlcNAc1-3)Gal-R] branches; core 2 6-GlcNAc-T in leukemic cells (named core 2 -GlcNAc-T L) is not accompanied by these two activities and has a more restricted specificity. Core 2 6-GlcNAc-T M and L both have an absolute requirement for the 4- and 6-hydroxyls ofN-acetylgalactosamine and the 6-hydroxyl of galactose of the Gal1-3GalNAc-benzyl substrate but the recognition of other substituents of the sugar rings varies, depending on the tissue. 3-sialytransferase from human placenta and from AML cells also showed distinct specificity differences, although the enzymes from both tissues have an absolute requirement for the 3-hydroxyl of the galactose residue of Gal1-3GalNAc-Bn. Gal1-3(6-deoxy)GalNAc-Bn and 3-deoxy-Gal1-3GalNAc-Bn competitively inhibited core 2 6-GlcNAc-T and 3-sialyltransferase activities, respectively.Abbreviations AFGP
antifreeze glycoprotein
- AML
acute myeloid leukemia
- Bn
benzyl
- CML
chronic myelogenous leukemia
- Fuc
l-fucose
- Gal, G
d-galactose
- GalNAc, GA
N-acetyl-d-galactosamine
- GlcNAc, Gn
N-acetyl-d-glucosamine
- HC
human colonic homogenate
- HO
hen oviduct microsomes
- HPLC
high performance liquid chromatography
- mco
8-methoxycarbonyl-octy
- Me
methyl
- MES
2-(N-morpholino)ethanesulfonate
- MK
mouse kidney homogenate
- onp
o-nitrophenyl
- PG
pig gastric mucosal microsomes
- pnp
p-nitrophenyl
- RC
rat colonic mucosal microsomes
- SA
sialic acid
- T
transferase
Enzymes: UDP-GlcNAc:Gal1-3GalNAc-R (GlcNAc to GalNAc) 6-N-acetylglucosaminyltransferase,O-glycan core 2 6-GlcNAc-transferase, EC 2.4.1.102; CMP-sialic acid: Gal1-3GalNAc-R 3-sialyltransferase,O-glycan 3-sialic acid-transferase, EC 2.4.99.4. 相似文献
8.
9.
The optimum geometries and binding energies of the complexes formed by AMPA and Kainic acid, as well as their anions with
tyrosine, proline and some tripeptides are investigated with quantum chemical calculations (HF/6-31G**). It was found that
receptors featuring the Tyr-Ala-Pro sequence exhibit stronger binding energies to the substrates than the Tyr-Ser-Pro and
Tyr-Ser-Ser. As expected, the anions are more bound than the neutral species. This work can lead to investigations on the
effect of AMPA receptors mutations on the brain functions, possibly related to criminal tendencies. 相似文献
10.
Yoshifumi Nishikawa Ayako Ogiso Kyohko Kameyama Maki Nishimura Xuenan Xuan Yuzuru Ikehara 《Experimental parasitology》2013
Recognition of sialylated glycoconjugates is important for host cell invasion by Apicomplexan parasites. Toxoplasma gondii parasites penetrate host cells via interactions between their microneme proteins and sialylated glycoconjugates on the surface of host cells. However, the role played by sialic acids during infection with T. gondii is not well understood. Here, we focused on the role of α2-3 sialic acid linkages as they appear to be widely expressed in vertebrates. Removal of α2-3 sialic acid linkages on macrophages by neuraminidase treatment did not influence the rate of infection or growth of T. gondii, nor did it affect phagocytosis in vitro. Sialyltransferase ST3Gal-I deficient mice (ST3Gal-I−/− mice) lost α2-3 sialic acid linkages in macrophages and spleen cells. The numbers of T. gondii-infected CD11b+ cells in peritoneal cavities of the infected ST3Gal-I−/− mice were relatively lower than those of the infected wild type animals. In addition, CD8+ T cell populations and numbers in the spleens and peritoneal cavities of the ST3Gal-I−/− mice were significantly lower than those in the wild type animals before and after the T. gondii infection. ST3Gal-I−/− mice had severe liver damage and reduced survival rates following peritoneal infection with T. gondii. Furthermore, adoptive transfer of immune CD8+ cells from wild type mice to ST3Gal-I−/− mice increased their survival during infection with T. gondii. Our data show that parasite invasion via α2-3 sialic acid linkages might not contribute on host survival and indicate the impact that loss of α2-3 sialic acid linkages has on CD8+ T cell populations, which are necessary for effective immune responses against infection with T. gondii. 相似文献
11.
12.
Schwab W Kasper M Gavlik JM Schulze E Funk RH Shakibaei M 《Histochemistry and cell biology》2000,113(3):221-225
Interactions between the extracellular matrix (ECM) and chondrocytes are of great importance for structure and function of
cartilage. The present study was undertaken to answer the question whether caveolins take part in integrin-mediated cell–ECM
interactions in the human cartilage. In samples of human knee joint cartilage, we detected the caveolin subtypes -1, -2, and
-3 by immunohistochemical methods. Double-label experiments revealed a colocalization of caveolin with β1-integrin. Results
of immunoprecipitation and immunoblotting assays show that β1-integrins associate with all three caveolin subtypes in human
chondrocytes and indicate that they are part of the same complexes. Furthermore, immunoelectron microscopy shows the localization
of β1-integrin in caveolae-like structures of the cell membrane. The data stimulate further investigations on the role of
the caveolin–integrin complex for integrin-mediated signaling pathways in chondrocytes.
Accepted: 17 December 1999 相似文献
13.
Hans Mulder Harry Schachter Jerry R. Thomas Koen M. Halkes Johannis P. Kamerling Johannes F. G. Vliegenthart 《Glycoconjugate journal》1996,13(1):107-113
Connective tissue of the freshwater pulmonateLymnaea stagnalis was shown to contain fucosyltransferase activity capable of transferring fucose from GDP-Fuc in 1–2 linkage to terminal Gal of type 3 (Gal1–3GalNAc) acceptors, and in 1–3 linkage to GlcNAc of type 2 (Gal1–4GlcNAc) acceptors. The 1–2 fucosyltransferase was active with Gal1–3GalNAc1-OCH2CH=CH2 (K
m=12 mM,V
max=1.3 mU ml–1) and Gal1–3GalNAc (K
m=20 mM,V
max=2.1 mU ml–1), whereas the 1–3 fucosyltransferase was active with Gal1–4GlcNAc (K
m=23 mM,V
max=1.1 mU ml–1). The products formed from Gal1–3GalNAc1-OCH2CH=CH2 and Gal1–4GlcNAc were purified by high performance liquid chromatography, and identified by 500 MHz1H-NMR spectroscopy and methylation analysis to be Fuc1–2Gal1–3GalNAc1-OCH2CH=CH2 and Gal1–4(Fuc1–3)GlcNAc, respectively. Competition experiments suggest that the two fucosyltransferase activities are due to two distinct enzymes.Abbreviations 2Fuc-T
1–2 fucosyltransferase
- 3Fuc-T
1–3 fucosyltransferase
- MeO-3Man
3-O-methyl-D-mannose
- MeO-3Gal
3-O-methyl-D-galactose 相似文献
14.
G. B. Chheda H. B. Patrzyc H. A. Tworek S. P. Dutta 《Nucleosides, nucleotides & nucleic acids》2013,32(7):1519-1537
Abstract A novel modified nucleoside, 1-α-D-Ribofuranosyl-4-pyridone-3-carboxamide, has been isolated from the urines of one normal human individual and two CML patients. The structure was assigned on the basis of UV, NMR and mass spectral data and confirmed by comparison with an authentic sample synthesized in our laboratory. This constitutes the first example of the occurrence of a nucleoside with an α-riboside linkage in human urine. 相似文献
15.
16.
Two water-soluble polymers, carrying 0.24 meq g–1 of lactosyl-(1-1)-sphingosine (7) and 0.13 meq g–1 of lactosyl-(1-3)-sphingosine (8) were prepared. The polymers served as acceptors in the -(2-3)-sialyltransferase reaction (up to 55.3 and 38.5% transfer yields, respectively). Subsequent photolysis, released compounds 11 (lyso-GM3) and 12 (lyso-GM3 analog), respectively; acylation and chromatography afforded (5-acetamido-3,5-dideoxy-D-glycero--D-galacto-2-nonulopyranosylonic acid)-(2-3)--D-galactopyranosyl-(1-4)--D-glucopyranosyl-(1-1)-(2S, 3R, 4E)-2-octadecanoylamino-4-octadecene-1,3-diol (13, GM3) and (5-acetamido-3,5-dideoxy-D-glycero--D-galacto-2-nonulopyranosylonic acid)-(2-3)--D-galactopyranosyl-(1-4)--D-glucopyranosyl-(1-3)-(2S, 3R, 4E)-2-octadecanoylamino-4-octadecene-1,3-diol (14, GM3 analogue), respectively, thus presenting a route to glycosphingolipids possessing the unusual glycosyl-(1-3)-spingosine linkage. 相似文献
17.
Paul A. Dawson Melissa L. HubbertAnuradha Rao 《Biochimica et Biophysica Acta (BBA)/Molecular and Cell Biology of Lipids》2010,1801(9):994-1004
The organic solute transporter (OST)(alpha)-OST(beta) is an unusual heteromeric carrier expressed in a variety of tissues including the small intestine, colon, liver, biliary tract, kidney, and adrenal gland. In polarized epithelial cells, OSTα-OSTβ protein is localized on the basolateral membrane and functions in the export or uptake of bile acids and steroids. This article reviews recent results including studies of knockout mouse models that provide new insights to the role of OSTα-OSTβ in the compartmentalization and metabolism of these important lipids. 相似文献
18.
John P. Wiebe 《Biochemical and biophysical research communications》1978,84(4):1003-1008
Sertoli cells from 17 day old rats convert progesterone to 20α-hydroxy-pregn-4-en-3-one and pregnenolone to 3β,20α-dihydroxy-5α-pregnane after 72 hours . The metabolites were identified by several systems of thin layer and gas chromatography, derivative formation and crystallization with authentic steroids. The production of 20α-hydroxy-pregn-4-en-3-one and 3β,20α-dihydroxy-5α-pregnane amounted to 1380 and 740 pmoles/h/mg protein which can account for the total amounts of these steroids reported in the testis. It is the first direct evidence that Sertoli cells can metabolize progesterone and pregnenolone and suggests that Sertoli cells contain the major, if not the only, amounts of 20α-hydroxysteroid dehydrogenase in the immature rat testis. 相似文献
19.
Yuta Sugiyama Yuji Honda Aina Gotoh Hisashi Ashida Shin Kurihara 《Bioscience, biotechnology, and biochemistry》2017,81(2):283-291
We have recently generated a highly efficient 1,2-α-l-fucosynthase (BbAfcA N423H mutant) by protein engineering of 1,2-α-l-fucosidase from Bifidobacterium bifidum JCM 1254. This synthase could specifically introduce H-antigens (Fucα1-2Gal) into the non-reducing ends of oligosaccharides and in O-linked glycans in mucin glycoprotein. In the present study, we show an extended application of the engineered 1,2-α-l-fucosynthase by demonstrating its ability to insert Fuc residues into N- and O-glycans in fetuin glycoproteins, GM1 ganglioside, and a plant-derived xyloglucan nonasaccharide. This application study broadens the feasibility of this novel H-antigen synthesis technique in functional glycomics. 相似文献
20.
Ashima Kapoor H. R. Singal Sunita Jain 《Journal of plant biochemistry and biotechnology.》2003,12(2):157-158
Infection of Brassica juncea plants with Albugo candida caused the induction of β-1,3-glucanase in the leaf tissues following inoculation; the induction being more pronounced in the resistant cultivars. The enzyme purified from infected leaves of resistant cultivar RC-781 had a molecular mass of 35.4 kD. The enzyme exhibited its optimum activity at 50°C and at pH 5.5 with Km value of 0.55 mg laminarin ml?1. The enzyme activity was slightly stimulated by Cl? and Mg++, while inhibited by Hg++ and Mn++ at higher concentrations only 相似文献