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

AcDNA encoding a new alpha2,8-sialyltransferase (ST8Sia IV), which exhibits activity toward the alpha,2,3-linked sialic acids of N-linked oligosaccharides, was cloned from a mouse lung cDNA library by means of the PCR-based approach. The predicted amino acid sequence of ST8Sia IV showed 15.2, 56.0, and 26% identity with those of so far cloned mouse alpha2,8-sialytransferases, i.e. GD3 synthase (ST8Sia I), STX(ST8Sia II), and Sia(alpha)2,3Galbeta1,4GlcNAc(alpha)2,8-sialyl-transferase (ST8Sia III). ST8Sia IV exhibits high amino acid sequence identity (99.2%) with recently cloned hamster polysialyltransferase-1 gene, which is necessary to polysialic acid expression, but no enzymatic activity of the gene product was reported [Eckhardt, M. et al. (1995) Nature 373, 715-718]. The ST8Sia IV gene was strongly expressed in lung, heart, and spleen, but only weak expression of the gene was observed in brain, without remarkable developmental regulation. The activity of mouse ST8Sia IV was specific toward sialylated glycoproteins. The linage-specific sialidase treatment of glycoproteins as well as N-linked oligosaccharides from the glycoproteins revealed that ST8Sia IV exhibits an alpha2,8-sialytransferase activity toward alpha2,3-linked sialic acids of N-linked oligosaccharides. ST8Sia IV can synthesize polysialic acid chain in vitro without any initiator sialytransferase.
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PMID:Molecular cloning and characterization of a third type of N-glycan alpha 2,8-sialyltransferase from mouse lung. 869 Jul 32

CstII from bacterium Campylobacter jejuni strain OH4384 has been previously characterized as a bifunctional sialyltransferase having both alpha2,3-sialyltransferase (GM3 oligosaccharide synthase) and alpha2,8-sialyltransferase (GD3 oligosaccharide synthase) activities which catalyze the transfer of N-acetylneuraminic acid (Neu5Ac) from cytidine 5'-monophosphate (CMP)-Neu5Ac to C-3' of the galactose in lactose and to C-8 of the Neu5Ac in 3'-sialyllactose, respectively (Gilbert M, Karwaski MF, Bernatchez S, Young NM, Taboada E, Michniewicz J, Cunningham AM, Wakarchuk WW. 2002. The genetic bases for the variation in the lipo-oligosaccharide of the mucosal pathogen, Campylobacter jejuni. Biosynthesis of sialylated ganglioside mimics in the core oligosaccharide. J Biol Chem. 277:327-337). We report here the characterization of a truncated CstII mutant (CstIIDelta32(I53S)) cloned from a synthetic gene whose codons are optimized for an Escherichia coli expression system. In addition to the alpha2,3- and alpha2,8-sialyltransferase activities reported before for the synthesis of GM3- and GD3-type oligosaccharides, respectively, the CstIIDelta32(I53S) has alpha2,8-sialyltransferase (GT3 oligosaccharide synthase) activity for the synthesis of GT3 oligosaccharide. It also has alpha2,8-sialidase (GD3 oligosaccharide sialidase) activity that catalyzes the specific cleavage of the alpha2,8-sialyl linkage of GD3-type oligosaccharides and alpha2,8-trans-sialidase (GD3 oligosaccharide trans-sialidase) activity that catalyzes the transfer of a sialic acid from a GD3 oligosaccharide to a different GM3 oligosaccharide (3'-sialyllactoside). The donor substrate specificity study of the CstIIDelta32(I53S) GD3 oligosaccharide synthase activity indicates that the enzyme is flexible in using different CMP-activated sialic acids and their analogs for the synthesis of GD3 oligosaccharides containing natural and nonnatural modifications at the terminal sialic acid.
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PMID:Multifunctionality of Campylobacter jejuni sialyltransferase CstII: characterization of GD3/GT3 oligosaccharide synthase, GD3 oligosaccharide sialidase, and trans-sialidase activities. 1850 8