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:3.2.1.26 (invertase)
4,927 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mannose-specific binding sites for horseradish peroxidase (HRP) were studied in paraformaldehyde-fixed, frozen sections of endocrine organs by a cytochemical method reported previously. In the testis, HRP was bound to interstitial cells, probably macrophages, and to sites extending along the surface of spermatozoa in the seminiferous tubules. In the epididymis, cells in the connective tissue, probably fibroblasts or macrophages, showed the specific reaction. In the ovaries, the reaction for lectin-bound HRP was observed in connective tissue cells of the theca externa, and in the mucosa of the uterus, binding of HRP occurred to many fibroblasts. The glycoprotein was also bound to cells in the connective tissue of the thyroid, probably mast cells, as well as to endothelial cells in the adrenal medulla and cortex. In all cases, the binding reaction required Ca2+ and was suppressed by mannose or mannan. Partially purified and highly purified preparations of glycoprotein hormones [ovine follicle-stimulating hormone, ovine luteinizing hormone, bovine thyroid-stimulating hormone, and human chorionic gonadotropin] as well as bovine thyroglobulin and yeast invertase competed with the binding of HRP to all the cells mentioned thus showing that the hormones were bound to the same sites as HRP. When 1 microM HRP was present in the incubation medium, the addition of 15-25 microM of highly purified hormones almost suppressed the reaction for lectin-bound HRP and competitive effects could be observed at even lower concentrations of the hormones.
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PMID:Competition between glycoprotein hormones and horseradish peroxidase for mannose-specific binding sites in cells of endocrine organs. 688 15

The effects of sodium butyrate, dimethyl sulfoxide (DMSO), and retinoic acid on the growth, morphology, carcinoembryonic antigen content, cell surface membrane-associated enzyme activities, and glycoprotein profiles of a human rectal adenocarcinoma cell line (HRT-18) in culture were compared. All three agents reversibly caused a marked increase in doubling times, a decrease in saturation densities, and a markedly reduced colony-forming efficiency in soft agar. Only butyrate caused gross morphological changes including cell enlargement, flattening, and increased membranous process formation. Carcinoembryonic antigen content was increased during culture in butyrate, while it was reduced by DMSO and unchanged by retinoic acid. The activities of membrane-associated enzymes were altered significantly in the butyrate-treated cells. For example, an increase in the activities of alkaline phosphatase (10-fold), gamma-glutamyl transpeptidase activity (3-fold) and sucrase activity (2-fold) was observed, while those of aminooligopeptidase and K+-stimulated phosphatase actually showed slight decreases. DMSO- or retinoic acid-treated cells showed a marked decrease in alkaline phosphatase activity, but other enzyme activities remained unchanged. Surface protein-labeling patterns of lactoperoxidase-catalyzed iodinated HRT-18 cells showed no significant change from the control cells following treatment with DMSO or retinoic acid. The most prominent change caused by butyrate treatment was the appearance of a major glycoprotein band with an apparent molecular weight of 60,000. These data indicate that the use of butyrate, DMSO, and retinoic acid may provide useful information concerning the identification of differentiation-associated markers of human rectal cancer cells. Furthermore, these agents, although having similar effects on the growth properties, have different effects on the morphology and on the biochemical properties of human rectal cancer cells.
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PMID:Differential effects of sodium butyrate, dimethyl sulfoxide, and retinoic acid on membrane-associated antigen, enzymes, and glycoproteins of human rectal adenocarcinoma cells. 705 70

Invertase from Baker's yeast (Saccharomyces cerevisiae) and Horseradish peroxidase (HRP) were covalently immobilized on Concanavalin A precoupled to Seralose via carbohydrate moieties. Covalent coupling of glycoenzymes was achieved by periodate induced aldehydic groups of glycosyls with amino groups of Concanavalin A, at different pH values. A bifunctional reagent such as glutaraldehyde crosslinks the glycoenzymes with lectin both intra and intermolecularly. Therefore, attempts were made to introduce covalent linkages between glycoenzymes and Concanavalin A-Seralose without intramolecular crosslinking in either. The immobilized preparations of glycoenzymes exhibited high yield of immobilization and eta value. About 90 and 85% covalent coupling could be observed in invertase and HRP at pH 7.0 respectively, as determined by treatment with 0.5 M methyl alpha-D-mannopyranoside. All immobilized glycoenzyme preparations exhibited marked stabilization towards thermal inactivation.
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PMID:Covalent immobilization of invertase and horseradish peroxidase on concanavalin A-Seralose via carbohydrate moieties. 754 67

Antisera raised against the plant glycoproteins beta-fructosidase and horseradish peroxidase can be fractionated on an affinity column of honeybee venom phospholipase A2 to produce serum fractions that are specific for either the alpha 1-->3 fucose or beta 1-->2 xylose epitopes commonly found on the Asn-linked glycans of plant glycoproteins. This affinity purification strategy relies on the absence of beta 1-->2 xylose from the glycan of the venom protein. Such antibody preparations can be used for the detection of these sugar epitopes on glycoproteins.
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PMID:Affinity purification of antibodies specific for Asn-linked glycans containing alpha 1-->3 fucose or beta 1-->2 xylose. 768 35

Entrapment in human alpha 2-macroglobulin (alpha 2M) of non-proteolytic enzymes was achieved with the help of trypsin covalently attached to Sepharose matrix. While it was also possible to achieve entrapment by the exposure of the alpha 2M: enzyme mixtures to soluble trypsin, use of the immobilized proteinase resulted in improved entrapment yields and also prevented the coentrapment of trypsin. Both soluble and immobilized trypsin transformed alpha 2M to the electrophoretically fast form but the immobilized trypsin required relatively longer incubation to bring about the transformation. Horseradish peroxidase was entrapped in higher yield in alpha 2M compared to the relatively high-molecular-weight invertase. alpha 2M-entrapped peroxidase and invertase appeared highly accessible to their respective substrates, as evident from their relatively unaltered Km values. alpha 2M-associated invertase, in spite of its large dimensions, failed to crossreact with the rabbit anti-invertase antiserum, indicating its physical entrapment rather than any other form of association.
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PMID:Entrapment of nonproteolytic enzymes in alpha 2-macroglobulin using immobilized trypsin. 769 19

Previous studies have suggested that a mannose receptor mediates the phagocytic uptake of effete rod outer segments by retinal pigment epithelial cells. In the present study, the effect of adding a soluble ligand for the mannose receptor, horseradish peroxidase, was examined. Cultured retinal pigment epithelial cells from Long Evans rats were preincubated with various concentrations of horseradish peroxidase for 20 min followed by a challenge of FITC-labeled bovine rod outer segments for 3 h. Both counts of total rod outer segments (bound and ingested) and ingested rod outer segments were determined. Rod outer segment uptake was reduced, in a concentration-dependent fashion, by an average of 60% of control values when horseradish peroxidase was added to retinal pigment epithelial cultures. Similarly, total rod outer segment values were reduced to 50% of controls in the presence of at least a 10 micrograms ml-1 horseradish peroxidase concentration. Horseradish peroxidase inhibition of retinal pigment epithelial phagocytic capacity was reversible. Other high mannose glycoproteins, such as invertase, beta-glucoronidase, and ovalbumin, were equally effective in preventing rod outer segment ingestion by retinal pigment epithelial cells. These data further support the hypothesis that a mannose receptor on the retinal pigment epithelial apical surface facilitates phagocytosis of rod outer segments.
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PMID:Natural, high-mannose glycoproteins inhibit ROS binding and ingestion by RPE cell cultures. 854 90

Samples of whole saliva and dental plaque were collected from initially 10-year old subjects who participated in a 40-month cohort study investigating the effect of chewing gum usage on caries rates. The subjects represented nine cohorts of which one did not receive gum, while in eight cohorts the subjects received gum containing either xylitol, sorbitol, their mixtures, or sucrose as bulk sweeteners, the maximum sweetener consumption in the form of gums being up to 10.7 g/day, used in 3-5 daily chewing episodes. Gum usage had no significant effect on the levels of salivary protein, IgA, alpha-amylase, peroxidase, lysozyme, SCN and buffer capacity. At the endpoint, the group that received 100% xylitol pellet-shaped gum five times/day, had significantly lower levels of sucrase (p <0.05) and free sialic acid (p < 0.001) in whole saliva than at baseline. This group showed significantly (p <0.05) smaller plaque index scores at two cross-sectional measurements, and exhibited the lowest log(10) counts of salivary lactobacilli at endpoint than most other groups. The salivary levels of peptidase(s) (oligopeptidase B-like enzymes) hydrolyzing N-alpha-benzoyl-DL-arginyl-p-nitroaniline were significantly (p<0.05) or almost significantly lower in groups which received 100% xylitol pellet gums. All groups exhibited obviously an aging-related increase of salivary mutans streptococcus scores, except the above xylitol group in which the mean scores did not change.
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PMID:Properties of whole saliva and dental plaque in relation to 40-month consumption of chewing gums containing xylitol, sorbitol of sucrose. 886 27

A fungus, Geotrichum candidum Dec 1, newly isolated as a dye-decolorizing microorganism, was used to decolorize molasses and an anthraquinone dye in shaken flasks. A degree of decolorization of molasses of 87% was achieved after 12 days of cultivation, and the maximum rate of decolorization of the dye in the culture broth was obtained in 7 days. The apparent activity of peroxidase in the molasses, which is responsible for dye decolorization, was significantly lower than that of purified peroxidase, due to the inhibition by molasses, but the inhibition was reduced after the fungus was fully grown. As two ultrafiltered fractions of molasses were similarly decolorized by Dec 1, Dec 1 apparently degraded colored substances of a wide range of molecular weights. When Dec 1 was cultivated in a medium in which sucrose in the molasses was hydrolyzed with invertase, the degree of decolorization of molasses, and rate of decolorization of the dye were similar to these obtained above.
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PMID:Decolorization of molasses and a dye by a newly isolated strain of the fungus Geotrichum candidum Dec 1. 1009 19

It has been shown that when two enzymes showing similar actions act in close proximity of each other they influence each other synergistically. The phenomenon of synergism is, however, not observed if the two enzymes are of dissimilar action type. The condition of closest proximity has been simulated by conducting the enzymic reactions inside the reversed micelles. In the present study we have experimented with alpha-amylase and invertase both hydrolysing enzymes and also with peroxidase and invertase which do not show similar actions.
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PMID:Synergistic effects in enzymic reactions. 1065 Jul 23

A study was made of the effect of the activity and purity of enzymes in the assay of total dietary fiber (AOAC Method 985.29) and specific dietary fiber components: resistant starch, fructan, and beta-glucan. In the measurement of total dietary fiber content of resistant starch samples, the concentration of alpha-amylase is critical; however, variations in the level of amyloglucosidase have little effect. Contamination of amyloglucosidase preparations with cellulase can result in significant underestimation of dietary fiber values for samples containing beta-glucan. Pure beta-glucan and cellulase purified from Aspergillus niger amyloglucosidase preparations were used to determine acceptable critical levels of contamination. Sucrose, which interferes with the measurement of inulin and fructooligosaccharides in plant materials and food products, must be removed by hydrolysis of the sucrose to glucose and fructose with a specific enzyme (sucrase) followed by borohydride reduction of the free sugars. Unlike invertase, sucrase has no action on low degree of polymerization (DP) fructooligosaccharides, such as kestose or kestotetraose. Fructan is hydrolyzed to fructose and glucose by the combined action of highly purified exo- and endo-inulinases, and these sugars are measured by the p-hydroxybenzoic acid hydrazide reducing sugar method. Specific measurement of beta-glucan in cereal flour and food extracts requires the use of highly purified endo-1,3:1,4 beta-glucanase and A. niger beta-glucosidase. Beta-glucosidase from almonds does not completely hydrolyze mixed linkage beta-glucooligosaccharides from barley or oat beta-glucan. Contamination of these enzymes with starch, maltosaccharide, or sucrose-hydrolyzing enzymes results in production of free glucose from a source other than beta-glucan, and thus an overestimation of beta-glucan content. The glucose oxidase and peroxidase used in the glucose determination reagent must be essentially devoid of catalase and alpha- and beta-glucosidase.
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PMID:Importance of enzyme purity and activity in the measurement of total dietary fiber and dietary fiber components. 1099 29


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