Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.1.53 (sialidase)
 2,694 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

T cells from enlarged lymph nodes of MRL/MpJ-lpr/lpr (lpr) mice were found to express more binding sites for strongly hemagglutinating Phaseolus vulgaris agglutinin (PHA-E4) and fewer binding sites for Ricinus communis aglutinin (RCA) than those from normal MRL/MpJ-+/+ (+/+) mouse lymph node. We found that high-molecular-weight (180K-220K) glycoproteins on lpr T cells were strongly stained with these lectins on Western-blotting. These glycoproteins were found to belong to the CD45 family, by absorption with monoclonal anti-CD45 antibody. We also found that the other glycoproteins (105K and 120K glycoproteins on lpr T cells and a 105K glycoprotein on +/+ T cells) were strongly stained with the lectins which preferentially bind to mucin-type (O-linked) sugar chains on the cell surface. These glycoproteins were found to be leukosialins, by absorption with anti-leukosialin serum. From the results of the lectin-binding to these glycoproteins after sialidase treatment, CD45 antigens and leukosialin molecules on lpr T cells were found to have many more terminal alpha 2,3-linked sialic acids than those on +/+ T cells, and this fact explains why lpr T cells have more binding sites for PHA-E4 but fewer binding sites for RCA.
 ...
PMID:Alpha 2,3-linked sialic acids are more abundant in CD45 antigens and leukosialins of abnormal T cells of lpr mice than in those of normal T cells. 253 27

The asparagine-linked sugar chains of human follicle-stimulating hormone (hFSH) were liberated as radioactive oligosaccharides from the polypeptide moiety by hydrazinolysis followed by N-acetylation and NaB3H4 reduction. Ninety-five percent of the oligosaccharides were acidic and all were converted to a mixture of neutral oligosaccharides on sialidase treatment. The mixture of neutral oligosaccharides was subjected to sequential immobilized lectin column chromatography on E-PHA-agarose, AAL-Sepharose, and Con A-Sepharose, and six fractions were obtained. The results of sequential exoglycosidase digestion of each oligosaccharide and methylation analysis led us to propose that the asparagine-linked sugar chains of hFSH are a mixture of complex-type bi-, tri-, and tetraantennary sialylated sugar chains with and without a fucose residue linked at the C-6 position of the proximal N-acetylglucosamine. Some of these sugar chains contain bisecting N-acetylglucosamine residue.
 ...
PMID:The asparagine-linked sugar chains of human follicle-stimulating hormone. 311 70

Malignant transformation is often accompanied by an aberrant glycosylation profile of the cell surface-in particular, the production of GlcNAcbeta1-6Manalpha1 branches in N-linked glycoproteins. To identify the target glycoproteins, we show a method using recombinant chicken N-acetylglucosaminyltransferase VI (GnT VI) and radiolabeled uridine (5'-)diphosphate-GlcNAc. The assay exploits the fact that GnT VI has a strict requirement for the GlcNAcbeta1-6Manalpha1 structure for activity, when a pyridylaminated free N-glycan is used as the acceptor substrate. Human asialo-agalacto alpha1-acid glycoprotein (AGP), which is known to contain GlcNAcbeta1-6Manalpha1 branches in its N-linked glycan chains, was radiolabeled when reacted with GnT VI, whereas human asialo-agalacto transferrin and bovine fetuin, neither of which contains a GlcNAcbeta1-6Manalpha1 structure were not, thus corroborating the specificity of the assay. Several proteins from human serum after pretreatment with sialidase and beta-galactosidase could be detected using the assay. One was identified as AGP from its mobility on SDS-PAGE, demonstrating the potential of this assay even with crude materials. Furthermore, this method could detect a protein that was also positively stained with leukoagglutinating phytohemagglutinin (L(4)-PHA) using glycoproteins prepared from WiDr human colon cancer cells. This method should provide a useful complement to the current method, which relies on the specificity of L(4)-PHA.
 ...
PMID:A specific detection of GlcNAcbeta1-6Manalpha1 branches in N-linked glycoproteins based on the specificity of N-acetylglucosaminyltransferase VI. 1642 2