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)

Lipid-bound sialic acid in the murine melanoma cell is not totally inaccessible to an exogenous macromolecular probe, as formerly believed. Roughly 30% of the dialic acid bound to lipid, and an equal proportion of the sialic acid bound to protein is cleaved by the action of Clostridium perfringens N-acetylneuraminate glycohydrolase (neuraminidase, sialidase) when the purified enzyme is added to the suspenion medium of intact murine melanoma cells freshly derived from the tumor. Cleavage of lipid-bound sialic acid is indifferent to the presence of Ca (2+) in the medium. However, maximum release from protein requires a physiological concentration of this divalent cation. Variation in ionic strength has no effect on release of sialic acid. These findings show that restricted portion of the bound sialic acid may be released from the intact murine melanama cell by the extracellularly supplied enzyme acting topographically.
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PMID:Accessibility of sialo components in a murine tumor cell to extracellular N-acetylneuraminate glycohydrolase (sialidase). 22 20

Sialidase (neuraminidase; acylneuraminyl hydrolase; EC 3.2.1.18)-treated erythrocytes obtained from different species are susceptible to rapid elimination from the circulation and are sequestered in the liver and spleen. The present studies were concerned with the mechanism of this clearance and how it may relate to the normal physiological process of removing senescent erythrocytes from the circulation. The results obtained indicate a preferential recognition of sialidase-treated as compared to normal erythrocytes by mono-nuclear spleen cells and Kupffer cells of the liver. This recognition manifests itself in both autologous and homologous systems by adhesion of the complementary cells in the form of rosettes, and as such could explain the removal of enzyme-treated erythrocytes from the circulation with their accumulation in liver and spleen. This phenomenon may represent a normal physiological mechanism for removal of senescent erythrocytes containing decreased sialic acid.
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PMID:Role of sialic acid in survival of erythrocytes in the circulation: interaction of neuraminidase-treated and untreated erythrocytes with spleen and liver at the cellular level. 26 92

Neuraminidase (sialidase) activity in concentrated culture filtrates of group B streptococci was measured with bovine submaxillary mucin as substrate. Group B streptococcal neuraminidase was not active on human alpha-1 acid glycoprotein and did not show increased activity on bovine submaxillary mucin that had been O-deacetylated by alkaline treatment. The enzyme was produced in a variety of media, including a chemically defined medium (FMC; Terleckyj et al., Infect. Immun. 11:649-655, 1975) supplemented with bovine serum albumin or human serum albumin. Maximal levels of activity were present in filtrates from cells grown in a dialyzable fraction of Todd-Hewitt broth harvested during the late exponential phase of growth. Dramatic decreases were seen when filtrates from the late stationary phase were assayed. The decrease in specific activity during the stationary phase was shown to be due to proteolytic digestion of neuraminidase and not to the elaboration of an extracellular neuraminic acid aldolase.
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PMID:Extracellular neuraminidase production by group B streptococci. 33 41

Observations have been made on two brothers who had progressive ataxia, intention myoclonus and visual failure starting early in the third decade of life. Their parents were consanguineous. The brothers showed bilateral cherry red spots at the maculae and bilateral perinuclear cataracts; their intelligence was preserved. Urine was found to contain large amounts of sialylated oligosaccharides; cultured skin fibroblasts showed deficiency of the enzyme sialidase (neuraminidase). Studies on leucocytes and cultured skin fibroblasts showed aberrant electrophoretic mobilities of six enzymes all of which are known to be glycoproteins, and this has been attributed to excessive amounts of sialic acid on the enzyme molecules. The clinical features together with the biochemical findings indicate that these are further cases of the newly described condition Sialidosis Type 1 and it is suggested that the electrophoretic findings might be typical of the condition.
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PMID:Sialidosis type 1: cherry red spot-myoclonus syndrome with sialidase deficiency and altered electrophoretic mobility of some enzymes known to be glycoproteins. II. Enzymes studies. 49 93

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

Mucolipidosis I is characterized by Hurler-like features and skeletal dysplasia with a cherry-red macular spot and signs of neurodegeneration involving neuronal cells and myelin. Excessive amounts of sialic acid-containing compounds were found in cultured fibroblasts, leukocytes, and urine of a patient with a clinical phenotype of mucolipidosis I. In cultured fibroblasts, profoundly diminished activity of an alpha-N-acetylneuraminidase (sialidase) was found. Mucolipidosis I thus appears to be a distinct disorder of complex carbohydrate catabolism caused by the genetic deficiency of a neuraminidase.
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PMID:Mucolipidosis I--a sialidosis. 61 Apr 23

An assay technique for determination of renal neuraminidase (sialidase) activity is described. Consistent and reproducible results were obtained in studies of rat renal tissue. Neuraminidase activity was detected in all human renal specimens studied; however the degree of activity was not related to the presence of renal calculi or infection.
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PMID:Human renal neuraminidase. 64 Aug 4

A 31-year-old male is described who has macular cherry-red spots, increased deep tendon reflexes and and myoclonus without dementia. An older brother died at age 33 of a disease with similar symptomatology. Homogenates of cultured fibroblasts from the patient exhibited 2.6, 8.1 and 12.4% of normal mean sialidase (neuraminidase, N-acetyl-neuraminosyl glycohydrolase, EC 3.21.18) activity, respectively, against 2-(3'-methoxyphenyl)-N-acetyl-alpha-neuraminic acid, N-acetyl-neuramin-lactose and fetuin. Activities of 14 other lysosomal enzymes were within the range of normal control fibroblasts. The sialidase activities in fibroblasts from the patient's parents and children were 30 to 67% of normal. It is concluded that this is the first proven case of a new autosomal recessive disorder resulting in cherry-red spots, myoclonus and a sialidase deficiency.
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PMID:Sialidase (alpha-n-acetyl neuraminidase) deficiency: the enzyme defect in an adult with macular cherry-red spots and myoclonus without dementia. 65 77

Some strains of Sporothrix schenckii and one strain of Ceratocystis stenoceras were investigated and the occurrence of the enzyme neuraminidase (= sialidase, N-acetylneuraminate glycohydrolase, EC 3.2.1.18) was proved not only by Warren's thiobarbituric acid assay but also by immunoelectrophoresis technique using monospecific antisera against 25 human glycoproteins, lipoproteins, immunoglobulins, fibrinogen and some other proteins (Table 1). There are also fibrinolytic and lipolytic enzyme activities in strains of Sporothrix chenckii corresponding with similar findings of other authors and also in the Ceratocystis stenoceras strain. The temperature optimum of production of neuraminidase seems to be lower than 37 degrees C (Table 2) and all strains failed to produce the enzyme after cultivation at 37 degrees C during some months. The findings of the existence of neuraminidase in the both species confirm also their close relationship. Because the occurrence of N-acylneuraminate was shown only in animals and in some microorganisms but not in plants it can be suggested that also Sporothrix schenckii and Ceratocystis stenoceras grow on animal or neuraminate containing microbial material but not on plants as it is assumed hitherto. Corresponding to this hypothesis the pathogenicity of Sporothrix schenckii and also the facultative pathogenicity of Ceratocystis stenoceras are to see in connexion with the action of neuraminidase and other enzymes metabolizing animal substrates. It can be concluded that neuraminidase is a possible additional pathogenic factor in sporotrichosis below 37 degrees C.
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PMID:[Occurrence of neuraminidase in Sporothrix schenckii and Ceratocystis stenoceras and its role in ecology and pathomechanism of these fungi (author's transl)]. 117 86

Trypanosoma cruzi invades a variety of mammalian cells by receptor-ligand interactions. In this review two T. cruzi carbohydrate-binding proteins, neuraminidase/trans-sialidase and penetrin, are discussed as possibly playing a role in parasite entry into mammalian cells.
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PMID:Entry of Trypanosoma cruzi into eukaryotic cells. 136 37


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