| 1. |
- Rosén, Stefan, et al.
(författare)
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A multispecific saline-soluble lectin from the parasitic fungus Arthrobotrys oligospora. Similarities in the binding specificities compared with a lectin from the mushroom agaricus bisporus.
- 1996
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Ingår i: European journal of biochemistry / FEBS. - : Wiley. - 0014-2956 .- 1432-1033. ; 238:3, s. 830-7
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Tidskriftsartikel (refereegranskat)abstract
- Several fungi can express high levels of saline-soluble and low-molecular-mass lectins that bind to glycoproteins such as fetuin and different mucins but not bind to any monosaccharides. In this paper, we report the binding specificities of such a lectin (designated AOL) isolated from the nematophagous fungus Arthrobotrys oligospora. The results show that AOL is a multispecific lectin that interacts with the following ligands: (a) Several sulfated glycoconjugates including sulfatide, dextran sulfate, and fucoidan. The specificity of this binding was indicated by experiments showing that none of the tested neutral- and sialic-acid-containing glycolipids, chondroitin sulfates B and C, heparin, and polyvinyl sulfate bound to AOL; (b) Phosphatidic acid and phospatidylglycerol, two out of several tested phospholipids. (c) N-linked and O-linked sugar chains bound to intact fetuin. The involvement of such sugar structures was demonstrated by analyzing the binding of AOL to chemically deglycosylated (trifluoromethanesulfonic acid) fetuin. Treating fetuin with O-glycosidase and N-glycosidase indicated that AOL bound to Gal beta GaLNAc alpha-Ser/Thr and to some N-linked complex sugars, respectively. Further assays demonstrated that AOL could interact with several other glycoproteins containing O-linked and/or N-linked sugar chains. The observations that AOL did not bind to free N-linked sugars isolated from fetuin, or to fetuin treated with trypsin or pronase, or to any of the tested neoglycoproteins and glycolipids with neutral- or sialic acid-containing sugars, indicated that the sugar chains need to be bound to an intact peptide backbone to interact with AOL. We have recently shown that the deduced primary structure of AOL has a high similarity to the sequence of a saline-soluble lectin isolated from the mushroom Agaricus bisporus (ABL) (Rosén, S., Kata, M., Persson, Y., Lipniunas, P. H., Wikström, M., van den Hondel, C. A. M. J. J., van den Brink, J. M., Rask, L., Hedén L.-O. and Tunlid, A., see companion paper). It is well known that ABL binds to Gal beta 3GaLNAc alpha-Ser/Thr, and in this paper we demonstrate that ABL binds to sulfatide, phosphatidic acid, phospatidylglycerol, and possibly also to the same N-linked complex sugars as AOL. The above data indicate that AOL and ABL are members of a novel family of fungal lectins sharing similar primary structure and binding properties.
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| 2. |
- Karlsson, Karl-Anders, 1935, et al.
(författare)
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Microbial interaction with animal cell surface carbohydrates.
- 1992
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Ingår i: APMIS. Supplementum. - 0903-465X. ; 27, s. 71-83
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Tidskriftsartikel (refereegranskat)abstract
- Microbes have selected primarily carbohydrates for attachment to host animal cells. Recent studies have revealed essential characteristics in the recognition of receptor carbohydrates. Of importance is the property of recognizing also sequences placed inside an oligosaccharide chain, which differs from most animal antibodies. This is the basis for series of isoreceptors with the minimum receptor sequence in common but with separate neighbouring groups. There are families of microbial ligands that show different preferences for members within one series of isoreceptors, indicating only slight differences in the complementary binding sites of the proteins. Such differences may explain shifts in the selectivity of separate host tissues for infection. A second characteristic is the low affinity interaction often found where simple receptor-containing saccharides are unable to inhibit attachment. Technical possibilities are rapidly developing for the design of synthetic receptor analogues to be used in the therapy of clinical infections. This is urgently needed in cases where no rational therapy exists today.
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| 3. |
- Karlsson, Karl-Anders, 1935, et al.
(författare)
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Unexpected carbohydrate cross-binding by Escherichia coli heat-labile enterotoxin. Recognition of human and rabbit target cell glycoconjugates in comparison with cholera toxin.
- 1996
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Ingår i: Bioorganic & medicinal chemistry. - 0968-0896. ; 4:11, s. 1919-28
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Tidskriftsartikel (refereegranskat)abstract
- The bacterial protein enterotoxins, cholera toxin (CT) of Vibrio cholerae and heat-labile toxin (LT) of Escherichia coli, induce diarrhea by enhancing the secretory activity of the small intestine of man and rabbit (animal model). This physiological effect is mediated by toxin binding to a glycolipid receptor, the ganglioside GM1, Gal beta 3GalNAc beta 4(NeuAc alpha 3)GAl beta 4Glc beta 1Cer. However, LT, but not CT, was recently shown by us to bind also to paragloboside, Gal beta 4GlcNAc beta 3Gal beta 4Glc beta 1Cer, identified in the target cells. By molecular modeling of this tetrasaccharide in the known binding site of LT, the saccharide-peptide interaction was shown to be limited to the terminal disaccharide (N-acetyllactosamine). This sequence is expressed in many glycoconjugates, and we have therefore assayed glycolipids and glycoproteins prepared from the target tissues. In addition to paragloboside, receptor activity for LT was detected in glycoproteins of human origin and in polyglycosylceramides of rabbit. However, CT bound only to GM1. Two variants of LT with slightly different sequences, human (hLT) and porcine (pLT), were identical in their binding to target glycoproteins and polyglycosylceramides, but different regarding paragloboside, which was positive for pLT but negative for hLT. This difference is discussed on basis of modeling, taking in view the difference at position 13, with Arg in pLT and His in hLT. Although N-acetyllactosamine is differently recognized in form of paragloboside by the two toxin variants, we speculate that this sequence in human glycoproteins and rabbit polyglycosylceramides is the basis for the common binding. Much work remains, however, to clear up up this unexpected sophistication in target recognition.
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| 4. |
- Lanne, B, et al.
(författare)
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Binding of the galactose-specific Pseudomonas aeruginosa lectin, PA-I, to glycosphingolipids and other glycoconjugates.
- 1994
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Ingår i: Glycoconjugate journal. - 0282-0080. ; 11:4, s. 292-8
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Tidskriftsartikel (refereegranskat)abstract
- The carbohydrate-binding specificity of Pseudomonas aeruginosa lectin I (PA-I) in iodinated or biotinylated form was studied. A large number of glycosphingolipids, as well as some glycoproteins and neoglycoproteins were used as ligands. Also, inhibition by free saccharides of PA-I binding to glycosphingolipids was tested. It was found that the lectin binds most strongly to terminal and nonsubstituted Gal alpha 3Gal- or Gal alpha 4Gal-structures.
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| 5. |
- Lanne, B, et al.
(författare)
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Glycoconjugate receptors for P-fimbriated Escherichia coli in the mouse. An animal model of urinary tract infection.
- 1995
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Ingår i: The Journal of biological chemistry. - 0021-9258. ; 270:15, s. 9017-25
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Tidskriftsartikel (refereegranskat)abstract
- Glycosphingolipids were isolated from kidneys, urethers, and bladders (including urethrae) of C3H/HeN mice. Binding was studied of a clinical isolate and recombinant strains of uropathogenic P-fimbriated Escherichia coli to these glycolipids. A series of receptor-active glycolipids with Gal alpha 4Gal in common, previously shown to be recognized by these bacteria, was identified by use of specific monoclonal antibodies, fast-atom bombardment and electron-impact mass spectrometry, and proton nuclear magnetic resonance spectroscopy: galabiosylceramide (Gal alpha 4Gal beta Cer), globotriaosylceramide (Gal alpha 4Gal beta 4Glc beta Cer), globoside (GalNAc beta 3Gal alpha 4Gal beta 4Glc beta Cer), the Forssman glycolipid (GalNAc alpha 3GalNAc beta 3Gal alpha 4Gal beta 4Glc beta Cer), Gal beta 4GlcNAc beta 6(Gal beta 3)GalNAc beta 3Gal alpha 4Gal beta 4Glc beta Cer, and Gal beta 4(Fuc alpha 3)GlcNAc beta 6(Gal beta 3)GalNAc beta 3Gal alpha 4Gal beta 4Glc beta Cer. The binding pattern for mouse kidney glycolipids differed from that for kidney glycolipids of man and monkey. In particular, the dominant 8-sugar glycolipid in the mouse was not detected in the primates. A second difference was found in the binding of E. coli to kidney glycoproteins on blots after electrophoresis; the mouse showed distinct receptor-active bands while human and monkey did not. These differences may be of relevance when using the mouse as a model for clinical urinary tract infection of man.
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| 6. |
- Larsson, Thomas, 1947, et al.
(författare)
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Use of an affinity proteomics approach for the identification of low-abundant bacterial adhesins as applied on the Lewis(b)-binding adhesin of Helicobacter pylori.
- 2000
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Ingår i: FEBS letters. - 0014-5793. ; 469:2-3, s. 155-8
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Tidskriftsartikel (refereegranskat)abstract
- Microbial attachment to host cell surfaces is considered to be the first essential step for colonization and infection. In most known cases, attachment is mediated by a specific protein-carbohydrate interaction. We have used a carbohydrate-containing crosslinking probe to select bacterial surface adhesins for trypsin digestion, MALDI-TOF mass spectrometry and identification against genome sequence. The present paper describes this functional proteomics approach for identification of the recently cloned low-abundant Lewis(b)-binding adhesin of Helicobacter pylori. Protein identification was obtained through the enrichment of approximately 300 fmol of adhesin from solubilized cells.
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| 7. |
- Miller-Podraza, Halina, 1948, et al.
(författare)
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Helicobacter pylori and neutrophils: sialic acid-dependent binding to various isolated glycoconjugates.
- 1999
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Ingår i: Infection and immunity. - 0019-9567. ; 67:12, s. 6309-13
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Tidskriftsartikel (refereegranskat)abstract
- Helicobacter pylori has been shown to agglutinate erythrocytes in a sialic acid-dependent manner. However, very few studies have examined relevant target cells in the human stomach. Neutrophils are required for the onset of gastritis, and the inflammatory reaction may be induced on contact between bacteria and neutrophils. In the present work, glycolipids and glycoproteins were isolated from neutrophils and were studied for binding by overlay with radiolabeled bacteria on thin-layer chromatograms and on membrane blots. There was a complex pattern of binding bands. The only practical binding activity found was sialic acid dependent, since treatment of glycoconjugates with neuraminidase or mild periodate eliminated binding. As shown before for binding to erythrocytes and other glycoconjugates, bacterial cells grown on agar bound to many glycoconjugates, while growth in broth resulted in bacteria that would bind only to polyglycosylceramides, which are highly heterogeneous and branched poly-N-acetyllactosamine-containing glycolipids. Approximately seven positive bands were found for glycoproteins, and the traditional ganglioside fraction showed a complex, slow-moving interval with very strong sialic-acid-dependent binding, probably explained by Fuc substitutions on GlcNAc.
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| 8. |
- Miller-Podraza, Halina, 1948, et al.
(författare)
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Recognition of glycoconjugates by Helicobacter pylori: an apparently high-affinity binding of human polyglycosylceramides, a second sialic acid-based specificity.
- 1996
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Ingår i: Glycoconjugate journal. - 0282-0080. ; 13:3, s. 453-60
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Tidskriftsartikel (refereegranskat)abstract
- Helicobacter pylori has been reported to agglutinate erythrocytes and to bind to various other cells in a sialic acid-dependent way. The binding was inhibited by sialyllactose or fetuin and other sialylated glycoproteins. The specificity apparently requires bacterial growth on agar, since we found that it was lost after growth in the nutrient mixture Ham's F12. Instead, the bacteria bound with high affinity and in a sialic acid-dependent way to polyglycosylceramides of human erythrocytes, a still incompletely characterized group of complex glycolipids. Bacteria grown in F12 medium were metabolically labelled with 35S-methionine and analysed for binding to glycolipids on thin-layer chromatograms and to glycoproteins on blots after electrophoresis, with human erythrocyte glycoconjugates in focus. There was no binding to simpler gangliosides including GM3 or sialylparagloboside, or to a mixture of brain gangliosides. In contrast, polyglycosylceramides of human erythrocyte membranes bound at a pmol level. The activity was eliminated by mild acid treatment, mild periodate oxidation or sialidase hydrolysis. Erythrocyte proteins as well as a range of reference glycoproteins did not bind except band 3, which was weakly active. However, this activity was resistant to periodate oxidation. These results indicate a second and novel sialic acid-recognizing specificity which is expressed independently of the previously described specificity.
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| 9. |
- Spåhr, H, et al.
(författare)
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Purification and characterization of RNA polymerase II holoenzyme from Schizosaccharomyces pombe.
- 2000
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Ingår i: The Journal of biological chemistry. - : Elsevier BV. - 0021-9258. ; 275:2, s. 1351-6
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Tidskriftsartikel (refereegranskat)abstract
- We have purified the RNA polymerase II holoenzyme from Schizosaccharomyces pombe to near homogeneity. The Mediator complex is considerably smaller than its counterpart in Saccharomyces cerevisiae, containing only nine polypeptides larger than 19 kDa. Five of these Mediator subunits have been identified as the S. pombe homologs to Rgr1, Srb4, Med7, and Nut2 found in S. cerevisiae and the gene product of a previously uncharacterized open reading frame, PMC2, with no clear homologies to any described protein. The presence of Mediator in a S. pombe RNA polymerase II holoenzyme stimulated phosphorylation of the C-terminal domain by TFIIH purified from S. pombe. This stimulation was species-specific, because S. pombe Mediator could not stimulate TFIIH purified from S. cerevisiae. We suggest that the overall structure and mechanism of the Mediator is evolutionary conserved. The subunit composition, however, has evolved to respond properly to physiological signals.
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| 10. |
- Wallinder, Jonas, et al.
(författare)
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Discovery of a novel circulating biomarker in patients with abdominal aortic aneurysm: a pilot study using a proteomic approach.
- 2012
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Ingår i: Clinical and translational science. - : Wiley. - 1752-8062 .- 1752-8054. ; 5:1, s. 56-9
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Tidskriftsartikel (refereegranskat)abstract
- Abdominal aortic aneurysm (AAA) is a common condition with high mortality when ruptured. Most clinicians agree that small AAAs are best managed by ultrasonographic surveillance. However, it has been stated in recent reviews that a serum/plasma biomarker that predicts AAA rupture risk would be a powerful tool in stratifying patients with small AAA. Identification of such circulating biomarkers has been to date unsuccessful. In this study, we used a proteomic approach to find new, potential plasma AAA biomarker candidates. Prefractionated plasma samples were analyzed by two-dimensional differential in-gel electrophoresis to identify differentially expressed proteins between four patients with small AAA and four controls without aneurysm. Protein spots that differed significantly between patients and controls were selected and identified by mass spectrometry. Three protein spots had significantly different expression between patients and controls. The most interesting finding was that patients with small AAA had increased levels of the enzyme glycosylphosphatidylinositol-specific phospholipase D (GPI-PLD) compared with the controls without aneurysm. In conclusion, by using a proteomic approach, this pilot-study provides evidence of GPI-PLD as a novel potential plasma biomarker for AAA.
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