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)

Chickens were exposed to SO2 in relatively low concentrations (3.4 to 18.5 parts per million (ppm)) for 1 to 14 days. A portion of their tracheas was embedded in water-soluble methacrylate, cut at 2 micrometer and stained with hematoxylin and eosin, Wright's stain, methyl green-pyronin, Alcian blue - periodic and Schiff, and for acid phosphatase. An increase was found in (a) the mucosa to wall ratio; (b) the number of mucosal cells in mitosis; (c) the number of macrophages, lymphocytes, plasma cells, and neutrophils in the epithelium and lamina propria; and (d) the number of these infiltrating cells which contained acid phosphatase. The number of mucus- and seromucus- secreting cells and vasoamine-containing cells were sometimes increased, but not consistently. The percentage of cells containing sialidase-sensitive sialomucins was elevated, and percentage of cells containing neutral mucins was reduced. These changes were only partly related to the SO2 concentration and the duration of SO2 exposure, in that increasing amounts of SO2 did not always cause increasing changes in the mucin composition. Evidently, the altered mucins sometimes protected against further mucin modification.
 ...
PMID:Quantitative histological changes produced in the tracheal mucosa of young chickens by the inhalation of sulfur dioxide in low concentrations. 55 68

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.
 ...
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.
 ...
PMID:Mucolipidosis I--a sialidosis. 61 Apr 23

The histology and mucosubstance histochemistry of the mongoose salivary glands were studied. Histologically, the mongoose salivary glands were generally similar to those in other carnivores (dog, cat and ferret). The mucosubstance histochemistry demonstrated considerable variations in the parotid, submandibular and sublingual glands in comparison to the other carnivores. The partoid gland contained carboxylated mucin which was sialidase-resistant. Granules in a few cells also contained sulphated mucin. Both submandibular and sublingual glands contained mainly carboxylated sialomucin which was sialidase-labile except in a few cell, some neutral mucin but no sulphated mucin. The molar and zygomatic glands were similar to those in the other carnivores. They contained both sulphated and carboxylated mucins but no neutral mucin. The carboxylated mucin was sialidase-resistant.
 ...
PMID:Histology and mucosubstance histochemistry of mongoose salivary glands. 63 29

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.
 ...
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.
 ...
PMID:Sialidase (alpha-n-acetyl neuraminidase) deficiency: the enzyme defect in an adult with macular cherry-red spots and myoclonus without dementia. 65 77

The presence of sialic acid on the cell surface is crucial for the survival of mammalian erythrocytes in circulation. In contrast, sialidase-treated chicken erythrocytes retain their viability in circulation. Galactose oxidase treatment of chicken red blood cells has no effect on their viability. However, after sialidase treatment, galactose oxidase treatment results in the rapid elimination of the chicken erythrocytes from circulation. This is compatible with the interpretation that consecutive treatment with the 2 enzymes abolishes the ability of the chicken erythrocytes to regenerate the sialic acid on the cell surface. Mammalian asialo-erythrocytes are sequestered in the liver and spleen. We have shown that at the cellular level there is a preferential recognition of sialidase-treated as compared to normal erythrocytes by mononuclear spleen cells and Kupffer cells of the liver. This recognition manifests itself in both autologous and homologous systems by rosette-like adhesions. These adhesions may represent the normal physiological mechanism for the removal of senescent erythrocytes from circulation by liver and spleen since it has been previously reported that older erythrocytes contain decreased amounts of sialic acid. The mechanisms in mammals for the elimination from circulation of asialo-erythrocytes and asialo-glycoproteins, while analogous in many respects, are definitely not identical.
 ...
PMID:Cell surface carbohydrate recognition and the viability of erythrocytes in circulation. 66 20

Dipeptidyl aminopeptidase IV was purified 350 fold from pig kidney by chromatographic procedures including affinity chromatography with conjugates of Gly-Pro linked to Sepharose 4.B. Purified enzyme existed in a dimeric form as determined by sodium dodecyl sulfate polyacrylamide-gel electrophoresis using dimethyl suberimidate (a cross-linking reagent). The molecular weight of the subunit was estimated to be 100 000 by gel filtration with 6 M guanidine hydrochloride and to be 94 000 based on analysis of N-terminal residue (dinitrophenyl-serine). The amino acid composition of the purified enzyme was also determined. The enzyme contained 18.3% of carbohydrate consisting of mannose, galactose, fucose, glucosamine and sialic acid. The enzyme desialized with sialidase was found to still possess full enzyme activity.
 ...
PMID:Dipeptidyl aminopeptidase IV, a glycoprotein from pig kidney. 66 15

Exposure to Hg2+ below 10 micrometer destroys synaptosomal membrane-associated sialidase of bovine brain in situ. Inhibition by Cu2+ occurs only at relatively higher concentrations, and is demonstrable after the synaptosomal membrane preparation has been presaturated with Cu2+ . Pb2+ does not inhibit enzymatic activity. Hg2+ does not exert a significant effect on the free energy of association of monomeric brain gangliosides into aggregates, or on the stability of the aggregate forms, as estimated by ultracentrifugal analysis of the ion-independent moment of ganglioside micelles as a function of concentration. Hg2+ inhibits synaptic membrane sialidase acting both in situ on the native sialocompounds in the membrane, or on exogenous ganglioside. Kinetic analyses of the exogenous activity in membranes exposed to Hg2+ reveal lowered Vmax values but no substantial change in Km for synaptosomal membrane gangliosides. These findings suggest that the powerful inhibitory effect exerted by Hg2+ on nerve ending membrane sialidase is enzyme directed, not substrate directed. It may be postulated that part of the neurotoxic effect of low levels of Hg2+ stems from an interference with synaptic metabolism by the destruction of membrane-associated sialidase. This enzyme can serve the purpose of modulation of synaptic negative charge density by releasing bound, strongly anionic, sialic acid from highly concentrated sialocompounds in the membrane.
 ...
PMID:Effect of neurotoxic divalent cations on the activity of the intrinsic nerve ending membrane-associated sialidase of bovine brain. 68 10

More than ten new types of gangliosides, in addition to haematoside and sialosylparagloboside, were isolated from human erythrocyte membranes. These were separated by successive chromatographies on DEAE-Sephadex, on porous silica-gel columns and on thin-layer silica gel as acetylated compounds. Highly potent blood-group-Ii and moderate blood-group-H activities were demonstrated in some of the ganglioside fractions. The gangliosides incorporated into cholesterol/phosphatidylcholine liposomes stoicheiometrically inhibited binding of anti-(blood-group I and i) antibodies to a radioiodinated blood-group-Ii-active glycoprotein. The fraction with the highest blood-group-I-activity, I(g) fraction, behaved like sialosyl-deca- to -dodeca-glycosylceramides on t.l.c. Certain blood-group-I and most of the -i determinants were in partially or completely cryptic form and could be unmasked by sialidase treatment. Thus the I and i antigens, which are known to occur on internal structures of blood-group-ABH-active glycoproteins in secretions, also occur in the interior of the carbohydrate chains of erythrocyte gangliosides.
 ...
PMID:Blood-group-Ii-active gangliosides of human erythrocyte membranes. 68 69


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>