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)

Neuraminidase [sialidase, EC 3.2.1.18] was found to be widely distributed in bacteria belonging to Arthrobacter. Among these bacteria, Arthrobacter ureafaciens, A. oxydans, and A. aurescens produced relatively potent neuraminidase activities. For the production of this enzyme, not only colominic acid, a homopolymer of N-acetylneuraminic acid, but also N-acetylneuraminic acid, the reaction product of this enzyme, are effective as sources of carbon. An affinity adsorbent specific for neuraminidase was prepared by cross-linking colominic acid with soluble starch by means of epichlorohydrin. Neuraminidase from A. ureafaciens could be purified on this affinity column. The purified neuraminidase was shown to be free from protease, N-acetylneuraminic acid aldolase, phospholipase C, and glycosidases. Aminoff's assay procedure for sialic acid was modified to avoid the centrifugation step. The modified procedure gave a higher molecular extinction coefficient.
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PMID:Distribution of neuraminidase in Arthrobacter and its purification by affinity chromatography. 59 9

Oligosaccharide side chains of human colonic mucins contain O-acetylated sialic acids and glycosulfate esters. Although these substituents are considered to protect the chains against degradation by bacterial glycosidases, sialate O-acetylesterase, N-acetylneuraminate lyase, and glycosulfatase activities have been found in fecal extracts. To better define the source of these activities, we measured extracellular and cell-bound sialidase, sialate O-acetylesterase, N-acetylneuraminate lyase, arylesterase, and glycosulfatase activities produced by 23 isolates of human fecal bacteria grown anaerobically in a hog gastric mucin culture medium; these represented dominant populations of fecal anaerobes, facultative anaerobes, and the subset of mucin oligosaccharide-degrading bacteria. Every strain produced sialidase and high levels of arylesterase, and all but five facultative anaerobes produced sialate O-acetylesterase. Sialic acids containing 2 mol or more of O-acetyl ester per mol of sialic acid were cleaved from mucin glycoproteins more slowly by sialidases of mucin oligosaccharide-degrading stains than were sialic acids containing 1 or 0 mol, and only N-acetyl- and mono-O-acetylated sialic acids were recovered from enzyme digests of a mucin containing di-O-acetylated sialic acids. No detectable N-acetylneuraminate lyase activity was produced by any strain, but low activity was induced by increasing the glycoprotein-bound sialic acid concentration in the culture medium of six Escherichia coli strains. Using lactitol-6-sulfate as a substrate, we found weak glycosulfatase activity in the partially purified, concentrated enzyme mixture in the culture supernatants of four mucin oligosaccharide-degrading strains but in none of the unconcentrated culture fractions. We conclude that the presence of two or more O-acetyl groups on sialic acids inhibits enteric bacterial sialidases but that production of sialate O-acetylesterases by several populations of enteric bacteria lessens the likelihood that mucin oligosaccharide chains terminating in O-acetylated sialic acids are protected from degradation. Sialate O-acetylesterases have a role in bacterial degradation of mucin glycoproteins in the human colon.
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PMID:Mucin degradation in the human colon: production of sialidase, sialate O-acetylesterase, N-acetylneuraminate lyase, arylesterase, and glycosulfatase activities by strains of fecal bacteria. 139 8

A rapid and sensitive assay by high-performance liquid chromatography for determination of the activity and substrate specificity of sialidase (EC 3.2.1.18) and N-acetylneuraminate lyase (EC 4.1.3.3) is described. Sialic acids were separated on a strong anion-exchange resin using 0.75 mM sodium sulfate as elution medium. This method allows the determination of a minimum amount of 200 pg (0.6 pmol) of sialic acid. Usually the enzyme mixtures were directly applied to the column without prior purification of substrates and products. The action of sialidase was studied either by the decrease of sialyllactose concentration or by the amount of sialic acid liberated. The relative hydrolysis rates of N-acetylneuraminyl-alpha(2-3)-lactose, N-glycolylneuraminyl-alpha(2-3)-lactose, N-acetylneuraminyl-alpha(2-6)-lactose, N-acetyl-9-O-acetylneuraminyl-alpha(2-3)-lactose, and N-acetyl-4-O-acetylneuraminyl-alpha(2-3)-lactose by Vibrio cholerae sialidase were 100, 88, 25, 12, and 0, respectively. The activity of N-acetylneuraminate lyase from Clostridium perfringens was determined by measuring the rate of disappearance of sialic acids or the formation of acylmannosamines, which is possible in the same chromatogram. Relative cleavage rates of N-acetylneuraminic acid, N-glycolylneuraminic acid, N-acetyl-9-O-acetylneuraminic acid, N-acetyl-7-O-acetylneuraminic acid, and N-acetyl-4-O-acetylneuraminic acid were found to be 100, 67, 24, 3, and 0, respectively. Comparison of the substrate specificities shows that substituents on the neuraminic acid molecule influence the reactions of both enzymes in a similar way.
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PMID:Analysis of sialidase and N-acetylneuraminate pyruvate-lyase substrate specificity by high-performance liquid chromatography. 287 83

In spite of the axially orientated hydroxy group at C-4, the benzyl alpha-glycoside of N-acetyl-4-epi-D-neuraminic acid (4-epi-NeuAc) is a substrate for sialidases from Vibrio cholerae, Clostridium perfringens, and Arthrobacter ureafaciens, although to an extent which differs depending on the enzyme. Surprisingly, V. cholerae sialidase is by far the slowest acting enzyme; this is in contrast to its usual behavior. Fowl plague virus sialidase and bovine testis sialidase also cleave this glycoside slowly. 4-Epi-NeuAc is not a substrate for N-acetylneuraminic acid aldolase from C. perfringens but reversibly inhibits the enzyme with a Ki = 2.3 mM. The N-acetylneuraminic acid analogue is not converted to the corresponding CMP-glycoside by CMP-sialic acid synthase from bovine brain; however, it is an effective reversible inhibitor of the enzyme. The kinetic properties were analyzed with an assay system at pH 9 as well as an assay system at pH 7.5. The results from Dixon and Hanes plots did not agree. Therefore, no conclusions about the mechanism of the inhibition could be reached. This is the first reported sialic acid analogue which can act as an inhibitor of CMP-sialic acid synthase.
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PMID:Interaction of N-acetyl-4-epi-D-neuraminic acid with key enzymes of sialic acid metabolism. 316 79

1. The activities of enzymes degrading human colonic mucin were examined in faecal specimens from healthy subjects and patients with inflammatory bowel disease. 2. The activity of sialidase was measured using a new physiological substrate related to mucus glycoproteins. In addition, acylneuraminate pyruvate-lyase (N-acetylneuraminate lyase; EC 4.1.3.3.) and a novel O-acetylsialic acid esterase (sialate O-acetylesterase; EC 3.1.1.53) were detected. 3. The O-acetylsialic acid esterase activity was readily detectable in partially purified fractions after Sephadex G-100 chromatography. 4. Patients with inflammatory bowel disease showed significant increases in acylneuraminate pyruvate-lyase and proteinase activity but sialidase activity did not differ from normal. The activity of these enzymes in neutrophils could not account for the differences observed.
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PMID:Degradation by bacterial enzymes of colonic mucus from normal subjects and patients with inflammatory bowel disease: the role of sialic acid metabolism and the detection of a novel O-acetylsialic acid esterase. 333 53

Nine strains of Streptococcus oralis, isolated from blood cultures of patients with infective endocarditis or from the oral cavity as part of the normal flora, were examined for their ability to elaborate sialidase (neuraminidase) and N-acetylglucosaminidase, enzymes which are involved in the degradation of glycoproteins. Both glycosidases were induced when bacteria were grown in a minimal medium supplemented with porcine gastric mucin, a model glycoprotein, and repressed when growth occurred in the presence of glucose. Cell-free extracts mucin-grown cultures expressed elevated levels of N-acetylneuraminate pyruvate-lyase (the first intracellular enzyme in the pathway of N-acetylneuraminate catabolism), N-acetylglucosamine (glcNAc)-6-phosphate deacetylase and glucosamine-6-phosphate deaminase (enzymes involved in the intracellular catabolism of GlcNAc 6-phosphate); activity of each of these intracellular enzymes was markedly repressed when bacteria were grown in media supplemented with alpha 1-acid glycoprotein, a major component of human plasma. Cells from these cultures expressed high levels of sialidase, N-acetylglucosaminidase, and the intracellular enzymes involved in the catabolism of N-acetyl-sugars released by action of these glycosidases. High-resolution 1H-NMR spectroscopy of spent culture supernatants revealed that sialic acid and GlcNAc residues of the molecularly mobile oligosaccharide side-chains of alpha 1-acid glycoprotein had been hydrolysed and the released sugars internalized by the bacteria. These data indicate that S. oralis has the ability to hydrolyse constituents of oligosaccharide side-chains of host-derived glycoproteins and to utilize simultaneously these released carbohydrates. The biochemical characteristics induced by the growth of S. oralis on glycoproteins may play a role in the survival and persistence of these bacteria at the infection site in vivo.
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PMID:Metabolism of glycoprotein-derived sialic acid and N-acetylglucosamine by Streptococcus oralis. 870 62

The importance of viridans streptococci as agents of serious extra-oral diseases, including endocarditis, is now recognized. We have tested the hypothesis that the ability to utilize sialic acid as a nutrient source may play a role in the proliferation of these organisms. The type strains of the 15 presently recognized species of viridans streptococci and two clinical isolates-S. oralis (AR3), isolated from a patient with infective endocarditis, and S. intermedius (UNS35), a brain abscess isolate-were studied for their ability to utilize sialic acid. Only S. oralis, S. sanguis, S. gordonii, S. mitis ("oralis group") S. intermedius, S. anginosus, S. constellatus ("milleri group"), and S. defectivus ("nutritionally variant group") were able to use sialic acid (N-acetylneuraminic acid) efficiently as a sole carbon source. Formate, acetate, and ethanol were produced as the major metabolic end-products of sialic acid metabolism, while corresponding glucose-grown cultures produced lactate as the major metabolic end-product. Utilization of sialic acid was independent of the production of sialidase. Cell-free extracts of sialic acid-grown cultures expressed elevated levels of N-acetylneuraminate pyruvate-lyase (NPL; the first enzyme in the intracellular catabolism of sialic acid) and N-acetylglucosamine-6-phosphate (GlcNAc-6-P) deacetylase and glucosamine-6-phosphate (GlcN-6-P) deaminase (enzymes involved in the intracellular catabolism of N-acetylglucosamine). These activities were repressed by growth in the presence of glucose. The intracellular fate of sialic acid, after cleavage by NPL into N-acetylmannosamine (ManNAc) and pyruvate, is uncertain, but the elevated levels of GlcNAc-6-P deacetylase and GlcN-6-P deaminase in sialic acid-grown cells suggest that phosphorylation and isomerization are possible steps in the metabolism of ManNAc to generate an intermediate common to the pathway of N-acetylglucosamine metabolism. The species of viridans streptococci that have the ability to utilize sialic acid are those most commonly associated with extra-oral diseases, and this ability is likely to play a role in the persistence and survival of these infecting organisms in vivo.
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PMID:Utilization of sialic acid by viridans streptococci. 890 24

Pasteurella species and related taxa are opportunistic pathogens parasitizing on mucous membranes of higher organisms containing sialic acids. Therefore, sialidase is a virulence factor which up to now has been described to be present in P. haemolytica, P. multocida, and P. volantium. Because of some taxonomic changes and the description of many new species or still unnamed groups, the presence of sialidase and the metabolic successor enzyme, N-acetylneuraminate lyase, was investigated in 65 Pasteurella or Pasteurella-like strains. The detection of enzymes was performed by colorimetry, by paper chromatography and immunoelectrophoresis. Using bovine submaxillary mucin as substrate, sialidases were produced in all strains studied although the activities were different. Most strains but not all were positive in N-acetylneuraminate lyase, too. Taken together, the strains of Pasteurella sensu stricto showed the strongest activities of sialidase, those of the Pasteurella aerogenes complex the lowest. However, because of loss of sialidase activity during subcultivation, there is little feasibility to characterize Pasteurella species by these enzymes.
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PMID:Occurrence of sialidase and N-acetylneuraminate lyase in Pasteurella species. 981 Jun 51

A new method is reported that can be performed within a single vessel to analyze the composition of aldose, hexosamine, and sialic acid residues of glycoproteins, glycolipids, and oligosaccharides. Glycoconjugates are treated with sialidase or subjected to mild acid hydrolysis, before being treated with N-acetylneuraminic acid aldolase to convert the free sialic acid residues to their corresponding N-acylmannosamines. The reaction mixture is then successively subjected to acid hydrolysis (in order to produce monosaccharides), N-acetylation, and conversion with p-aminobenzoic acid ethyl ester (ABEE). The ABEE-converted monosaccharides are simultaneously determined by reverse-phase high-performance liquid chromatography. Determination of the sugar compositions of bovine fetuin, II3NeuGc alpha-LacCer, and 3'-sialyllactose with this method was found to be highly accurate. Linearity of the peak area vs. the amount of bovine fetuin ranged from 1 to 50 micrograms in all ABEE-converted monosaccharides. With a slight modification to this method, sialic acid residues can be separately determined as NeuAc and NeuGc. This novel method and its modified version are used to demonstrate the sugar compositions of alpha 1-acid glycoproteins from several sources.
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PMID:New method for determining the sugar composition of glycoproteins, glycolipids, and oligosaccharides by high-performance liquid chromatography. 1050 Sep 97

This paper describes the first report on the development, characterization, and applications of a prototype amperometric biosensor for free sialic acid (SA). The sensor was constructed by the coimmobilization of two enzymes, i.e., N-acetylneuraminic acid aldolase and pyruvate oxidase, on a polyester microporous membrane, which was then mounted on top of a platinum disk electrode. The SA biosensor operation was based on the sequential action of the two enzymes to ultimately produce hydrogen peroxide, which was then detected by anodic amperometry at the platinum electrode. The surface of the platinum electrode was coated with an electropolymeric layer to enhance the biosensor selectivity in the presence of interfering oxidizable species. Optimization of the enzyme layer composition resulted in a fast and steady current response in phosphate buffer pH 7.2 at 37 degrees C. The limit of detection was 10 microM, and the response was linear to 3.5 mM (r = 0.9987). The prepared SA biosensors retained approximately 85% of their initial sensitivity after 8 days and showed excellent response reproducibility (CV = 2.3%). Utilization of a third enzyme, sialidase, expanded the scope of the present SA biosensor to determine bound sialic acid as well. The merits of the described biosensor allowed its successful application in determining SA in biological and pharmaceutical samples. The obtained results indicated that the presented SA biosensor should be a useful bioanalytical tool in several biological and clinical applications such as screening of SA as a nonspecific tumor marker as well as monitoring of tumor therapy.
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PMID:Prototype amperometric biosensor for sialic acid determination. 1729 71


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