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)

Nonidet P40 solubilized up to 90% of the sialidase, active towards added ganglioside substrate, that was associated with the total membrane fraction prepared from gray matter of bovine brains. Solubilized sialidase acted upon endogenous substrate (sialic acid containing compounds solubilized with the enzyme), hydrolyzing approximately 50% of the readily available sialosyl residues within 20 min. During a 2-hr reaction time 80% of the polysialylated gangliosides solubilized with the enzyme were acted upon. A 20-min lag was observed before sialidase acted upon added ganglioside substrate. The lag could be reduced to less than 2 min when the enzyme was allowed to act on endogenous substrate prior to exposure to exogenous substrate, suggesting that the solubilized enzyme acted preferentially on endogenous substrate. A protease inhibitor prevented much of the 86% loss of activity towards added substrate that was seen when the enzyme was stored at 4 degrees C for 6 days; activity towards endogenous substrate decreased only 34%.
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PMID:Association of endogenous substrate with solubilized bovine brain sialidase. 395 29

Human tissue factor pathway inhibitor is a protease inhibitor with three tandem Kunitz-type inhibitory domains. The recombinant protein (r-hTFPI) was produced using Chinese hamster ovary cells, and its polypeptide and carbohydrate chain structures were analyzed. The complete amino acid sequence, composed of 276 residues, was determined using a protein sequencer after protease digestion and it was identical to that predicted from the cDNA sequence. Among three potential N-glycosylation sites, both Asn117 and Asn167 were fully N-glycosylated but Asn228 was not. Thr175 was also fully O-glycosylated, but Ser174 was partially O-glycosylated. Carbohydrate composition and mass spectrometric analyses of the undecapeptide OG-11 (residues Leu 170approximately Leu180) showed that two O-linked carbohydrate chains consisted of a type-1 core structure (Gal-GalNAc-Ser/Thr) with 0-3 mol of N-acetylneuraminic acid(s). The N-linked carbohydrate chains were analyzed by two-dimensional carbohydrate mapping combined with sequential glycosidase digestion, after the reducing-ends of carbohydrate residues were tagged with 2-aminopyridine and non-reducing-end sialic acids were removed with sialidase. All the N-linked structures in r-hTFPI were complex-type carbohydrate chains with one fucose residue attached to the reducing-end GlcNAc and consisted of bi-, tri-, and tetraantennary carbohydrate chains in the ratio 1.9:1.3:1.0. Fucosylated tri- and tetraantennary carbohydrate chains with one or two N-acetyllactosaminyl repeats were also found (30% of carbohydrate chains determined). Thus, the region between Kunitz domains 2 and 3 encoded by exon 7 was highly glycosylated by two O-linked carbohydrate chains at Ser174 and Thr175 and one N-linked carbohydrate chain at Asn167. These results indicated that the region is occupied by a cluster of three bulky and acidic carbohydrate chains.
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PMID:Amino acid sequence and carbohydrate structure of a recombinant human tissue factor pathway inhibitor expressed in Chinese hamster ovary cells: one N-and two O-linked carbohydrate chains are located between Kunitz domains 2 and 3 and one N-linked carbohydrate chain is in Kunitz domain 2. 863 92