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)

Artificial multienzyme complexes were prepared in which enzymes were covalently bound to polysaccharide structures activated with urea and formaldehyde. Double enzyme complexes of glucose oxidase and catalase, a glucose oxidase and invertase, were prepared by immobilization on to cellulose fabric. Also, catalase was covalently bound to soluble dextran. The resulting multienzyme systems were highly active and stable, making them suitable for use in measuring the concentrations of glucose and saccharose in solutions. The measurements were performed using an amperometric oxygen electrode and multienzyme membranes containing glucose oxidase and catalase for the first substrate, as well as glucose oxidase bound to cheese-cloth and a 'liquid' membrane of dextran-bound catalase. To determine the concentration of saccharose, a multienzyme membrane with bound glucose oxidase and invertase was used in combination with a 'liquid' dextran-catalase. The enzyme electrodes exhibited a measuring range of 0.1-5 mol dm-3 and a response time of 2-3 min. The electrodes may be used for measuring saccharose and glucose concentrations both in fermentation broths and food products.
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PMID:Multienzyme membranes for biosensors. 137 9

A blotting method is described to detect enzymes that do not normally yield a colored product. The method can be used for dot blotting as well as blotting after gel electrophoresis of many enzymes if the reactions they catalyze can be coupled to an oxidase or a dehydrogenase. The latter, designated "auxiliary enzymes," are preimmobilized on membranes of nitrocellulose or positively charged nylon and the reaction they catalyze is coupled with reduction of tetrazolium salt to yield colored formazan on areas of the transfer membrane occupied by the blotted enzymes. In the examples reported here, preimmobilized glucose oxidase, L-amino acid oxidase, xanthine oxidase, malate dehydrogenase, and a mixture of hexokinase and glucose-6-phosphate dehydrogenase were used as auxiliary enzymes to detect blotted invertase, leucine aminopeptidase, purine nucleoside phosphorylase, fumarase, and adenylate kinase, respectively. Detection limits varied, but never exceeded 100 ng for these enzymes. After blotting from polyacrylamide gels, the fumarase assay was the most sensitive of those investigated, detecting 10 ng of enzyme used for electrophoresis. Invertase, a glycoprotein, was detected with higher sensitivity on nitrocellulose membranes when concanavalin A was present on the membrane in addition to the auxiliary enzyme, glucose oxidase. On blots from isoelectric focusing gels, the assay detected two isozymes of purine nucleoside phosphorylase in a sample from calf spleen and at least five isozymes of this enzyme in lysates from human red cells.
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PMID:Activity staining of blotted enzymes by reaction coupling with transfer membrane-immobilized auxiliary enzymes. 245 38

An approach to the mechanism which may govern the behaviour of biological compartmentalized systems is presented. Artificial enzyme membranes with immobilized glucose oxidase, invertase or hexokinase were used to separate two compartments of a specially designed diffusion cell. Asymmetry in volume, hydrodynamic conditions and enzyme location was purposely chosen in order to create situations which could not be obtained with an enzyme free in solution, and was then used to tentatively mimic situations existing in vivo. Experiments were conducted and a translocation effect of H2O2, glucose and glucose 6-phosphate was obtained. A theoretical analysis taking into account the different identified parameters of the system was elaborated.
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PMID:Mimicked translocation of glucose and glucose 6-phosphate with artificial enzyme membranes. 276 83

Each of the three high-mannose type glycoproteins studied, acid phosphatase, invertase, and glucose oxidase, could be specifically cross-linked through its carbohydrate chains. The procedure involves periodate oxidation of carbohydrate residues followed by reaction of the generated aldehyde groups with adipic acid dihydrazide as a cross-linker. The amount and size as well as solubility of the formed polymers could be efficiently controlled by varying the reaction conditions, i.e., the oxidation degree and the concentrations of glycoproteins, cross-linker, and hydrogen ions during the cross-linking reaction. It was found that the quantity and size of polymers increased with oxidation degree and protein concentration and by lowering the pH. When the protein concentration was above and pH below certain values, depending on the glycoenzyme, insoluble polymers formed. The soluble cross-linked polymers retained a high level of original activity, and the minor decrease in specific activity noticed was shown to occur during the periodate oxidation step. The cross-linked glycoenzymes are much more resistant to denaturation by high temperature and by changes in pH, demonstrating the usefulness of this method in preparation of the stabilized glycoprotein derivatives.
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PMID:Preparation of the stabilized glycoenzymes by cross-linking their carbohydrate chains. 284 Aug 55

Enzyme immunoassays for 17 alpha-hydroxyprogesterone (17-OHP) were developed. Horseradish peroxidase (HRP), glucose oxidase (GOD), invertase (INV) and glucose-6-phosphate dehydrogenase (G6PDH) were used as label enzymes. Double antibody coated beads or tubes were used for separating the bound and free fractions. Antisera used were prepared by using 4-carboxyethylthio-17-OHP and 3-carboxymethyl oxime-17-OHP-bovine serum albumin as immunogens. The bridge heterologous system was more sensitive than other site heterologous and homologous systems. The minimum amounts of 17-OHP detected were 0.25 and 1.0 pg/tube for fluorescence EIAs using HRP and GOD, and 0.1, 10 and 0.1 pg/tube for chemiluminescence EIAs using GOD, INV and G6PDH, respectively. The reproducibility and correlation with RIA were also studied. The present study demonstrates the feasibility of a neonatal screening for congenital adrenal hyperplasia.
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PMID:Fluorescence and chemiluminescence enzyme immunoassays of 17 alpha-hydroxyprogesterone in dried blood spotted on filter paper. 332 May 34

1. Glucose oxidase (EC 1.1.3.4), amyloglucosidase (EC 3.2.1.3), invertase (EC 3.2.1.26) and beta-galactosidase (EC 3.2.1.23) were covalently attached via glutaraldehyde to the inside surface of nylon tube. 2. The linked enzyme system, comprising invertase immobilized within a nylon tube acting in series with glucose oxidase immobilized in a similar way, was used for the automated determination of sucrose. 3. The linked enzyme system, comprising beta-galactosidase immobilized within a nylon tube acting in series with glucose oxidase immobilized in a similar way, was used for the automated determination of lactose. 4. The linked enzyme system, comprising amyloglucosidase immobilized within a nylon tube acting in series with glucose oxidase immobilized in a similar way, was used for the automated determination of maltose. 5. Mixtures of glucose oxidase and amyloglucosidase were immobilized within the same piece of nylon tube and used for the automated determination of maltose. 6. Mixtures of glucose oxidase and invertase were immobilized within the same piece of nylon tube and used for the automated determination of sucrose.
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PMID:Preparation of some immobilized linked enzyme systems and their use in the automated determination of disaccharides. 420 8

An optimal, in respect to productivity (activity X stability), enzyme ratio for immobilization of multienzyme systems was calculated by using the kinetic parameters (KM and Vmax), data on the stability and yield of each enzyme during immobilization. The experimental data, obtained during combined immobilization of invertase, mutarotase and glucose oxidase, illustrate the theoretical propositions.
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PMID:[Choice of the initial enzyme correlation in immobilizing polyenzyme systems]. 636 82

Based on a glucose oxidase sensor for determination of glucose several glucoseoxidase bioenzyme electrodes have been developed. Enzymes producing glucose by hydrolysis of saccharides (glucamylase, invertase, cellulase) as well as glucose consuming systems (hexo-kinase, glucose dehydrogenase) have been coupled to glucose oxidase. The function of the bienzyme systems was demonstrated by concentration measurements (blood glucose, maltose, ATP, NAD+, starch) and enzyme activity measurements (alpha-amylase, ATPase, lactate dehydrogenase).
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PMID:Glucose oxidase bienzyme electrodes for ATP, NAD+, starch and disaccharides. 677 73

A simple strategy for increasing considerably the quantities of glycoenzymes immobilized on insoluble supports is described. The strategy that we call bioaffinity layering makes use of the multivalent nature of concanavalin A (Con A) and the multiple oligosaccharide chains of most glycoenzymes to build alternating lectin and glycoenzyme layers on a Sepharose matrix with precoupled Con A. Using this procedure, it was possible to increase the amounts of several glycoenzymes immobilized on Sepharose and 19.0 mg glucose oxidase could be associated with one ml Sepharose matrix after seven Con A/glucose oxidase incubation cycles. Bioaffinity layered preparations of glycoenzymes exhibited high activities as indicated by very high effectiveness factor (eta) values and those of glucose oxidase and invertase exhibited a layer-by-layer increase in thermostability. The sensitivity of a flow-through glucose monitoring cartridge integrated into a flow injection analysis (FIA) system was enhanced significantly by increasing the amount of immobilized glucose oxidase via bioaffinity layering. A cartridge bearing six layers of glucose oxidase on Sepharose support was used effectively and repeatedly for analysis of medium glucose concentration during a fed-batch cultivation of the yeast Saccharomyces cerevisiae.
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PMID:Bioaffinity layering: a novel strategy for the immobilization of large quantities of glycoenzymes. 924 93

The glycosylated enzymes (invertase and glucose oxidase) were used as the competitive markers for a simple and rapid determination of the lectin-saccharide interactions. The method, based on the formation of the conjugate of an appropriate glycoenzyme with the specific carbohydrate-binding lectins and the inhibition of the conjugate formation with a monosaccharide, was described. This method was used to estimate the relative carbohydrate specificity of Concanavalin A for monosaccharides derived from D-mannose. The inhibition effect of the saccharides on the formation of Concanavalin A-glycosylated enzyme precipitate was compared with their influence on the enzyme sorption on conjugate Concanavalin A-bead cellulose support. The amount of the interacting enzyme was estimated either indirectly from its concentration in a supernatant that was determined spectrophotometrically (Con A was in a free or immobilized form) or directly in the immobilized form linked to Con A-sorbent using the flow microcalorimetric method. The results obtained, using different methods, agreed in general.
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PMID:The glycosylated enzyme-binding assay for the study of the interaction of free and immobilized lectins with carbohydrates. 931 Aug 66


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