Thermal stabilization of glucose oxidase and glucoamylase by physical entrapment

Physical entrapment was used as an approach to achieve thermal stabilization of enzymes. The t 1/2 values for the thermoinactivation of glucose oxidase and glucoamylase were increased several-fold by their entrapment in polyacrylamide gels. In polyacrylate gels the individual enzymes behaved differently, probably owing to microenvironmental effects arising by the polyelectrolyte nature of the carrier.

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Water-soluble enzyme-polymer grafts: Thermal stabilization of glucose oxidase

Biotechnology and Bioengineering ◽

10.1002/bit.260150518 ◽

1973 ◽

Vol 15 (5) ◽

pp. 1011-1016 ◽

Cited By ~ 18

Author(s):

H. F. Hixson

Keyword(s):

Glucose Oxidase ◽

Thermal Stabilization ◽

Water Soluble ◽

Soluble Enzyme

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Electronic tongue formed by sensors and biosensors containing phthalocyanines as electron mediators: Application to the analysis of red grapes

Journal of Porphyrins and Phthalocyanines ◽

10.1142/s1088424613501137 ◽

2014 ◽

Vol 18 (01n02) ◽

pp. 76-86 ◽

Cited By ~ 18

Author(s):

Cristina Medina-Plaza ◽

Gema Revilla ◽

Raquel Muñoz ◽

José Antonio Fernández-Escudero ◽

Enrique Barajas ◽

...

Keyword(s):

Glucose Oxidase ◽

Electronic Tongue ◽

Principal Component ◽

Carbon Paste ◽

Electron Mediator ◽

Enzyme Substrate ◽

Voltammetric Sensors ◽

The Individual ◽

Electron Mediators

An electronic tongue formed by voltammetric sensors and biosensors containing phthalocyanines has been developed and used to analyze grapes of different varieties. The sensors are prepared using the carbon paste technique and have been chemically modified with different metallophthalocyanines. In turn, biosensors consist of carbon paste electrodes modified with phthalocyanines combined with tyrosinase or glucose oxidase. The response of the individual sensors towards model solutions of glucose and catechol have demonstrated that the voltammetric responses depend on the nature of the phthalocyanine, evidencing the important role of the electron mediator in the performance of the sensors. The capability of the system to discriminate grapes according to their sugar and their polyphenolic content has been evidenced using Principal Component Analysis. It has been demonstrated that the proposed array of sensors combines the advantages of classical phthalocyanine based sensors — that provide global information about the sample —, with the specificity of the enzyme substrate reaction typical of biosensors. For this reason, the selectivity of the multisensor system and its capability of discrimination is clearly improved when biosensors containing glucose oxidase or tyrosinase are included in the array.

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Inducible versus constitutive social immunity: examining effects of colony infection on glucose oxidase and defensin-1 production in honeybees

Royal Society Open Science ◽

10.1098/rsos.170224 ◽

2017 ◽

Vol 4 (5) ◽

pp. 170224 ◽

Cited By ~ 10

Author(s):

Margarita M. López-Uribe ◽

Andrea Fitzgerald ◽

Michael Simone-Finstrom

Keyword(s):

Glucose Oxidase ◽

Social Immunity ◽

Hypopharyngeal Gland ◽

Larval Food ◽

Collective Effort ◽

Pathogen Challenge ◽

Before And After ◽

The Individual ◽

Pathogen Exposure ◽

Colony Level

Honeybees use a variety of defence mechanisms to reduce disease infection and spread throughout the colony. Many of these defences rely on the collective action of multiple individuals to prevent, reduce or eradicate pathogens—often referred to as ‘social immunity’. Glucose oxidase (GOX) and some antimicrobial peptides (e.g. defensin-1 or Def1) are secreted by the hypopharyngeal gland of adult bees on larval food for their antiseptic properties. Because workers secrete these compounds to protect larvae, they have been used as ‘biomarkers’ for social immunity. The aim of this study was to investigate if GOX and Def1 are induced after pathogen exposure to determine whether its production by workers is the result of a collective effort to protect the brood and colony in response to a pathogen challenge. Specifically, we quantified GOX and Def1 in honeybee adults before and after colony-level bacterial infection by American foulbrood ((AFB), Paenibacillus larvae ). Overall, our results indicate that levels of GOX and Def1 are not induced in response to pathogenic infections. We therefore conclude that GOX and Def1 are highly constitutive and co-opted as mechanisms of social immunity, and these factors should be considered when investigating immunity at the individual and colony level in social insects.

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Rapid Glucose Oxidase-Peroxidase Ultramicro Method for Determination of Blood Glucose

Clinical Chemistry ◽

10.1093/clinchem/16.5.427 ◽

1970 ◽

Vol 16 (5) ◽

pp. 427-430 ◽

Cited By ~ 8

Author(s):

Paul H Lenz ◽

Anthony J Passannante

Keyword(s):

Blood Glucose ◽

Benzoic Acid ◽

Glucose Oxidase ◽

Phosphate Buffer ◽

Room Temperature ◽

Protein Precipitation ◽

Reagent Blank ◽

The Individual ◽

H Protein

Abstract A rapid, convenient, and easy ultramicro modification of the glucose oxi-dase-peroxidase method for determining blood glucose is described. The reagent mixture is prepared by mixing phosphate buffer (pH 5.0) with lyophilized enzyme-chromogen (o-dianisidine). To this is added 20 µl of plasma or serum. After 15 min at room temperature the reaction is stopped, and the reaction mixture cleared, by adding 4M HCI. Absorbance is read at 400 nm vs. a reagent blank or, preferably, against a reagent blank containing serum or plasma. The individual (prepackaged) reagents are stable for at least 10 months; the reagent mixture and the color of the acidified reaction product are stable for more than 5 h. Protein precipitation, apparently un-necessary, has been eliminated. Absorbancies obtained by this method are linear for glucose concentrations as great as 300 mg/100 ml. Heparin, Parasepts, and benzoic acid do not inhibit the reaction.

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The pH Dependence of the Individual Steps in the Glucose Oxidase Reaction

Journal of Biological Chemistry ◽

10.1016/s0021-9258(18)83415-9 ◽

1969 ◽

Vol 244 (13) ◽

pp. 3625-3634

Author(s):

H J Bright ◽

M Appleby

Keyword(s):

Glucose Oxidase ◽

Ph Dependence ◽

The Individual ◽

Oxidase Reaction

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Development of a glucose oxidase-based biocatalyst adopting both physical entrapment and crosslinking, and its use in biofuel cells

Nanoscale ◽

10.1039/c6nr00902f ◽

2016 ◽

Vol 8 (17) ◽

pp. 9201-9210 ◽

Cited By ~ 41

Author(s):

Yongjin Chung ◽

Yeonjoo Ahn ◽

Marcelinus Christwardana ◽

Hansung Kim ◽

Yongchai Kwon

Keyword(s):

Glucose Oxidase ◽

Biofuel Cells ◽

Physical Entrapment

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Radioiodination of an outer membrane protein in intact Rickettsia prowazekii

Infection and Immunity ◽

10.1128/iai.29.2.831-834.1980 ◽

1980 ◽

Vol 29 (2) ◽

pp. 831-834 ◽

Cited By ~ 1

Author(s):

D K Smith ◽

H H Winkler

Keyword(s):

High Resolution ◽

Membrane Protein ◽

Glucose Oxidase ◽

Outer Membrane ◽

Outer Membrane Protein ◽

External Environment ◽

Polyacrylamide Gels ◽

Rickettsia Prowazekii ◽

Inner Membrane

Intact Rickettsia prowazekii was radiolabeled with the glucose oxidase-lactoperoxidase method of iodination. Separation of the rickettsial extract into cytoplasmic, outer and inner membrane fractions demonstrated that the outer membrane was preferentially labeled. Analysis of the polypeptides of these fractions on high-resolution slab polyacrylamide gels showed that most of the 125I was in polypeptide T49, an outer membrane constituent. Additional outer membrane polypeptides were iodinated in broken envelope preparations, demonstrating that T49 is uniquely accessible to the external environment and the asymmetric polypeptide organization of the outer membrane.

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Cyanogen bromide cleavage of proteins in sodium dodecyl sulphate/polyacrylamide gels Diagonal peptide mapping of proteins from epidermis

Biochemical Journal ◽

10.1042/bj1970591 ◽

1981 ◽

Vol 197 (3) ◽

pp. 591-597 ◽

Cited By ~ 36

Author(s):

J D Lonsdale-Eccles ◽

A M Lynley ◽

B A Dale

Keyword(s):

Sodium Dodecyl Sulphate ◽

Peptide Mapping ◽

Sodium Dodecyl ◽

Distinct Group ◽

Newborn Mouse ◽

Polyacrylamide Gels ◽

Structural Protein ◽

Human Proteins ◽

Methionine Residues ◽

The Individual

A two-dimensional electrophoretic procedure employing CNBr has been devised for the analysis of proteins in sodium dodecyl sulphate/polyacrylamide gels. The technique allows the detection of an unusual class of epidermal proteins that lack methionine. The proteins have been identified by this method in newborn mouse, rat, and rabbit, because they are stable in the presence of CNBr and consequently lie on a diagonal. Adult human epidermis also contains CNBr-stable proteins, but in lesser amounts than in the newborn rabbit or newborn rodents. The methionine-containing proteins (i.e., the keratins) are degraded by CNBr into a series of unique and characteristics peptides which lie below the diagonal. Inter- and intra-species similarities and differences exist between the individual keratins, depending on the number and distribution of their methionine residues. The peptide-map patterns for the rodent and lagomorph proteins are more similar to each other than to that for the human proteins. The maps for rat and rabbit skin proteins are the most similar. We conclude that the epidermal keratins are a closely related, yet individually distinct, group of proteins that are found in conjunction with a class of proteins that lack methionine. The latter proteins are related to the histidine-rich basic protein, an epidermal structural protein that aggregates with keratin filaments.

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