Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

Clostridium perfringens sialidase was purified by affinity chromatography. Kinetic properties of the enzyme were examined with sialyllactose and with mixed sialoglycolipids (gangliosides) as substrates. With the latter substrate in 0.01 M Tris-acete in the absence of strong electrolyte, the pH optimum for enzymatic activity was 6.8. Addition of strong electrolyte (0.01 to 0.10 M Nac1) to the reaction medium caused an acidic shift and a broadening of the pH optimum, Enzymatic activity at pH 5.8 rose approximately 2.5-fold; a concomitant loss of activity at pH 6.8 was also observed. The alteration of enzymatic activity caused by strong electrolyte were dependent upon changes in Vmax. Km remained nearly invariant. Thus, a reversible transition of the enzyme from a relatively inactive to a highly active form occurred as a function of strong electrolyte concentration. Determination of the pK values of the active functional groups of C. perfringens sialidase revealed that the effects of strong electrolyte were exerted upon the pKa group of the enzyme. Strong electrolyte appeared to shield unfavorable electrostatic interactions between polyanionic sialoglycolipid micelles and the enzyme molecule, thus protecting the pKa group from inactivation. In comparision with the effects of strong electrolyte upon enzymatic activity toward the sialoglycolipid substrate, those observed with the monovalent substrate, sialyllacthose, were minor. Collectively, these findings indicate that ionic environment may effectively control the activity and relative substrate specificity of C. perfringens sialidase at a given pH. Furthermore, they explain the low pH optima and skewed pH profiles previously reported for enzymatic activity toward high molecular weight substrates.
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PMID:Effects of strong electrolyte upon the activity of Clostridium perfringens sialidase toward sialyllactose and sialoglycolipids. 0 Mar 84

Biochemical characterization of hemagglutinin and sialidase activities from Clostridium perfringens strain CN3870 revealed that this strain produced three sialidase enzymes that were separable to gel filtration, ion exchange chromatography, and polyacrylamide gel electrophoresis. The molecular weights of sialidase I, II, and III activities were 310,000 +/- 10,000, 105,000 +/- 4,000 and 64,000 +/- 2,000, respectively, the first figure being an approximate value only.
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PMID:Relationship between hemagglutinin and sialidase from Clostridium perfringens CN3870: chromatographic characterization of the biologically active proteins. 0 34

Gel filtration of supernatant fluids, from the wild-type Clostridium perfringens, strain CN3870, and several of the mutants and reverants derived from this strain, showed that these mutants failed to product detectable amounts of still produced sialidase III activity. The reverants tested had regained the ability to produce approximately wild-type levels of the I and II forms of both activities. These results showthat there is a direct relationship between the production of the I form and hemagglutinin and sialidase activities and the production of the II form of these biologically active proteins. Models that explain the genetic basis for these results are discussed.
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PMID:Relationship between hemagglutinin and sialidase from Clostridium perfringens CN3870: gel filtration of mutant and reverant activities. 0 35

The interaction of human organ alkaline phosphatases (orthophosphoric-monoester phosphohydrolases (alkaline optimum), EC 3.1.3.1) with sugars was studied. Hexosamines, N-acetylneuraminic acid (NANA or sialic acid), N-acetylmuramic acid and N-acetylglycolylneuraminic acid inhibited human organ alkaline phosphatase activities. Of these, sialic acid was the most effective inhibitor. The pH profiles for the enzymes in the absence and presence of sialic acid were similar. The sialic acid - enzyme complex was more heat stable than the free enzyme between 20 and 45 degrees C. Lineweaver-Burk plots of 1/v versus 1/S at various concentrations of sialic acid showed intersecting straight lines indicating that the mechanism of inhibition was a mixed type. The Ki value obtained from the plots of 1/v versus the square of sialic acid concentration was 0.07 mM for the hepatic, sialidase-treated hepatic, and intestinal alkaline phosphatases. The respective Hill coefficients varied somewhat with the alkaline phosphatase isoenzyme. Hyperbolic curves were obtained when the percentage of remaining activity was plotted against the substrate concentration at different concentrations of sialic acid. The Hill coefficient was lowered in the presence of sialic acid. The sialidase-treated hepatic enzymes used gave the most effective conversion. Partial denaturation of the enzyme with urea, or pronase digestion had a little if any effect on the sialic acid inhibition with constant time.
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PMID:Inhibition of alkaline phosphatase by sialic acid. 1 56

Acid mucopolysaccharides in mast cell granules were histochemically studied in the lesion of urticaria pigmentosa and in the dermis of normal human skin. Alcian blue and azure A were used to stain mucopolysaccharides. Bromphenol blue was employed for detection of basic proteins. In a further attempt to identify various polyanions, staining was carried out with alcian blue containing various concentrations of electrolytes. Methylation, saponification, and digestion with streptomyces or testicular hyaluronidase, chondroitinase ABC, sialidase, or desoxyribonuclease were also employed. The results obtained are most likely to suggest the presence of hyaluronic acid in mast cell granules.
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PMID:Histochemical demonstration of hyaluronic acid in human dermal mast cells. 5 4

Acid mucopolysaccharides in dermal papillae of hair follicles from both bald and on-bald regions of the scalp of stump-tailed macaques were studies histochemically. Alcian Blue, Azure A and Periodic acid Schiff methods were used for staining mucopolysaccharides, and Bromphenol Blue for staining basic proteins. In an attempt to identify various polyanions, staining was carried out with Alcian Blue containing different concentrations of electrolytes. Methylation, saponification, mild acid hydrolysis and digestion with streptomyces or testicular hyaluronidase, chondroitinase ABC, or sialidase, were also used. The results indicate that chondroitin sulphate B is present in the papillae of terminal hair follicles in early and intermediate anagen, and degraded chondroitin sulphates are present in the papillae of vellus and terminal hair follicles in late anagen.
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PMID:Acid mucopolysaccharides in hair papillae of the stump-tailed macaque (Macaca speciosa). 5 48

The ultrastructural cytochemistry of the alveolar-capillary "membrane" has been investigated. Dialyzed iron and high iron diamine staining demonstrated a layer containing sulfated mucosubstance at the basal surface of the membranous pneumocytes. In the same layer, fixation with an osmium tetroxide-potassium pyroantimonate solution yielded abundant fine precipitates which were abolished by inclusion of ehtylene glycol bis-N,N'-tetraacetic acid (EGTA) in the fixative. This cation-retaining layer could be interpreted as providing a mechanism for retarding cation transport from the basement membrane to the alveolar space. High iron diamine staining also demonstrated a layer of sulfated mucosubstance on the microvilli of the granular pneumocytes. This layer corresponded with a sialidase-resistant, dialyzed iron-reactive stratum which overlaid the sialomucin-rich cell coat.
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PMID:A cation-retaining layer in the alveolar-capillary membrane. 6 17

Gc-globulin or group-specific component, also known as the vitamin D-binding protein, was investigated by the combined use of electrofocusing and immunofixation. Serum of the Gc 2-2 type was found to contain a single protein band whereas serum of the Gc 1-1 type shows two bands with a lower isoelectric point. The Gc 1-2 type contains all three bands known as Gc-2 (pI 5.10), Gc-1Slow (pI 5.03), and Gc-1Fast (pI 4.95). Each apoprotein shows an anodal shift of about 0.07 pH unit after incubation with an excess of 25-hydroxycholecalciferol. After treatment with sialidase Gc-1Fast focuses in the position of Gc-1Slow, whereas the position of Gc-2 remains unchanged.
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PMID:The heterogeneity of human Gc-globulin. 7 72

Asialoorosomucoid and asialofetuin were prepared by using sialidase, which was removed chromatographically before the proteins were labelled with radioactive iodine. After intravenous administration of a small amount oa asialoglycoprotein (3--4 microgram/100 g body wt.) protein-bound and non-protein radioactivities in plasmas and livers of rats were determined at intervals over a period of 30 min. Transfer of either tracer protein from plasma to liver was almost complete in 5 min. Proteolysis of asialofetuin was evident very shortly thereafter, but degradation of asialoorosomucoid commenced after a significant delay and was initially slow relative to that of asialofetuin. Studies in vitro with crude hepatic lysosomal enzyme preparations indicated that asialoorosomucoid was less readily digested than asialofetuin, and that desialylation of orosomucoid or fetuin did not noticeably increase the susceptibility of these proteins to protease action. Proteolysis of asialofetuin was also demonstrable in liver homogenates in conditions under which albumin and asialotransferrin were stable. A generalized mathematical model was devised to represent the uptake and degradation of asialoglycoproteins by the liver. The theoretical assumptions that gave the best fits with experiment are outlined and discussed.
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PMID:Hepatic uptake and degradation of trace doses of asialofetuin and asialoorosomucoid in the intact rat. 8 27

A case of adult type mucolipidosis with beta-galactosidase and sialidase deficiency is described. This patient, a woman aged 20, had mental retardation, macular cherry-red spots, corneal clouding, gargoyle-like face, cerebellar ataxia, myoclonus and convulsions beginning at the age of 14. Bony deformities, vacuoles in the peripheral lymphocyte and foamy cells in the bone marrow were also noted. Biopsy study of the sural nerve and vermiform appendix disclosed many vacuoles in almost every kind of cells, although the accumulated substance in these vacuoles could not be characterized histochemically or ultrastructurally. Deficient leukocyte beta-galactosidase and sialidase were confirmed. There was increased urinary sialoglycopeptide and increased siliac acid and hexosamine in the glycoprotein of lymphocytes. Leukocytes sialidase activites of the parents were 30 to 50% of the control values. These results suggest a genetic defect of sialidase.
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PMID:Adult type mucolipidosis with beta-galactosidase and sialidase deficiency. Histological and biochemical studies. 9 67


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