scholarly journals Enzymatically triggered rupture of polymersomes

Soft Matter ◽  
2016 ◽  
Vol 12 (4) ◽  
pp. 1014-1020 ◽  
Author(s):  
Woo-Sik Jang ◽  
Seung Chul Park ◽  
Ellen H. Reed ◽  
Kevin P. Dooley ◽  
Samuel F. Wheeler ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Glucose Oxidase

Polymersomes are robust vesicles made from di-block co-polymers. We have engineered a two step enzymatic cascade to trigger the release of contents from polymersomes, in which extravesicular glucose oxidase makes hydrogen peroxide, when then penetrates the membrane and is converted by entrapped catalase to oxygen, leading to vesicle failure.

scholarly journals Decomposition of Glucose-Sensitive Layer-by-Layer Films Using Hemin, DNA, and Glucose Oxidase

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 319 ◽  
Author(s):  
Kentaro Yoshida ◽  
Yu Kashimura ◽  
Toshio Kamijo ◽  
Tetsuya Ono ◽  
Takenori Dairaku ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Glucose Oxidase ◽  
Dna Cleavage ◽  
Electrostatic Interactions ◽  
Glucose Solution ◽  
Layer By Layer ◽  
Sensitive Layer ◽  
Physiological Conditions ◽  
Lbl Films ◽  
Low Glucose

Glucose-sensitive films were prepared through the layer-by-layer (LbL) deposition of hemin-modified poly(ethyleneimine) (H-PEI) solution and DNA solution (containing glucose oxidase (GOx)). H-PEI/DNA + GOx multilayer films were constructed using electrostatic interactions. The (H-PEI/DNA + GOx)5 film was then partially decomposed by hydrogen peroxide (H2O2). The mechanism for the decomposition of the LbL film was considered to involve more reactive oxygen species (ROS) that were formed by the reaction of hemin and H2O2, which then caused nonspecific DNA cleavage. In addition, GOx present in the LbL films reacts with glucose to generate hydrogen peroxide. Therefore, decomposition of the (H-PEI/DNA + GOx)5 film was observed when the thin film was immersed in a glucose solution. (H-PEI/DNA + GOx)5 films exposed to a glucose solution for periods of 24, 48 72, and 96 h indicated that the decomposition of the film increased with the time to 9.97%, 16.3%, 23.1%, and 30.5%, respectively. The rate of LbL film decomposition increased with the glucose concentration. At pH and ionic strengths close to physiological conditions, it was possible to slowly decompose the LbL film at low glucose concentrations of 1–10 mM.

Nitroalkanes as Reductive Substrates for Flavoprotein Oxidases

1972 ◽  
Vol 27 (9) ◽  
pp. 1052-1053 ◽  
Author(s):  
David J. T. Porter ◽  
Judith G. Voet ◽  
Harold J. Bright
Keyword(s):  
Hydrogen Peroxide ◽  
Amino Acid ◽  
Glucose Oxidase ◽  
Ph Dependence ◽  
Kinetic Mechanism ◽  
Acid Oxidase ◽  
Amino Acid Oxidase ◽  
Kinetics Of ◽  
Oxidase Reaction ◽  
Detailed Kinetic Mechanism

Nitroalkanes have been found to be general reductive substrates for D-amino acid oxidase, glucose oxidase and L-amino acid oxidase. These enzymes show different specificities for the structure of the nitroalkane substrate.The stoichiometry of the D-amino acid oxidase reaction is straightforward, consisting of the production of one mole each of aldehyde, nitrite and hydrogen peroxide for each mole of nitroalkane and oxygen consumed. The stoichiometry of the glucose oxidase reaction is more complex in that less than one mole of hydrogen peroxide and nitrite is produced and nitrate and traces of 1-dinitroalkane are formed.The kinetics of nitroalkane oxidation show that the nitroalkane anion is much more reactive in reducing the flavin than is the neutral substrate. The pH dependence of flavin reduction strongly suggests that proton abstraction is a necessary event in catalysis. A detailed kinetic mechanism is presented for the oxidation of nitroethane by glucose.It has been possible to trap a form of modified flavin in the reaction of D-amino acid oxidase with nitromethane from which oxidized FAD can be regenerated in aqueous solution in the presence of oxygen.

Study on Determination of Glucose in Amylofermentation Liquid Using Ultraviolet Spectrophotometry

2012 ◽  
Vol 538-541 ◽  
pp. 2434-2437 ◽  
Author(s):  
Bao Shan He ◽  
Na Gao ◽  
Fang Wei ◽  
Qi Yu Lu
Keyword(s):  
Hydrogen Peroxide ◽  
Glucose Oxidase ◽  
Optical Method ◽  
Maximum Absorption ◽  
Ultraviolet Spectrophotometry ◽  
Titanyl Oxalate ◽  
Maximum Absorption Wavelength ◽  
Absorption Wavelength

In the presence of glucose oxidase, glucose in samples was oxygenated to hydrogen peroxide, the solution turned from colourless to yellow upon the reaction of potassium titanyl oxalate to the generated hydrogen peroxide. Using ultraviolet spectrophotometry, a new optical method for detecting glucose in amylofermentation liquid has been established. Results demonstrated that glucose concentrations were proportional to absorbance at the maximum absorption wavelength of 380 nm. A favorable linearity was presented in the range of 1 mmol/L to 60 mmol/L. The linear coeffciency was 0.993. This method was simple, reliable, and could be used for determing glucose in samples.

Lung edema due to hydrogen peroxide is independent of cyclooxygenase products

1984 ◽  
Vol 56 (4) ◽  
pp. 900-905 ◽  
Author(s):  
O. Burghuber ◽  
M. M. Mathias ◽  
I. F. McMurtry ◽  
J. T. Reeves ◽  
N. F. Voelkel
Keyword(s):  
Hydrogen Peroxide ◽  
Glucose Oxidase ◽  
Direct Action ◽  
Active Oxygen Species ◽  
Active Oxygen ◽  
Lung Edema ◽  
Oxygen Species ◽  
Edema Formation ◽  
Prostaglandin Production ◽  
Prostaglandin F2 Alpha

Active oxygen species can cause lung injury. Although a direct action on endothelial cells is proposed, the possibility exists that they might cause injury via mediators. We considered that active oxygen species would stimulate the generation of cyclooxygenase metabolites, which then alter pulmonary vasoreactivity and cause edema. We chemically produced hydrogen peroxide by adding glucose oxidase to a plasma- and cell-free, but beta-D-glucose-containing, solution, which perfused isolated rat lungs. Addition of glucose oxidase to the perfusate caused a marked decrease in pulmonary vasoreactivity, accompanied by an increase in the concentrations of prostacyclin, thromboxane A2, and prostaglandin F2 alpha. Pretreatment with catalase, a specific scavenger of hydrogen peroxide, preserved pulmonary vasoreactivity, inhibited the increase of the concentration of the measured prostaglandins, and prevented edema formation. Indomethacin effectively blocked lung prostaglandin production but neither prevented the decrease in vasoreactivity nor inhibited edema formation. From these data we conclude that hydrogen peroxide impaired pulmonary vasoreactivity and subsequently caused edema. Despite the fact that hydrogen peroxide stimulated lung prostaglandin production, cyclooxygenase-derived products neither caused the decrease in vasoreactivity nor the development of edema.

Automated Fluorometric Micromethod for Blood Glucose

1973 ◽  
Vol 19 (11) ◽  
pp. 1296-1299 ◽  
Author(s):  
Carl W Seiter ◽  
Hoyle D Hill ◽  
George K Summer
Keyword(s):  
Hydrogen Peroxide ◽  
Blood Glucose ◽  
Horseradish Peroxidase ◽  
Glucose Oxidase ◽  
Filter Paper ◽  
Whole Blood ◽  
Homovanillic Acid ◽  
Phenylacetic Acid ◽  
Condensation Product ◽  
Fluorometric Method

Abstract We describe a sensitive automated fluorometric method for glucose in whole blood spotted on filter paper. By action of glucose oxidase (EC 1.1.3.4) on glucose, hydrogen peroxide is produced, which then reacts with 4-hydroxy-3-methoxy-phenylacetic acid (homovanillic acid) in the presence of horseradish peroxidase (EC 1.11.1.7) to form a fluorescent condensation product. Obtained at a rate of 60 samples per hour, the results are accurate, linear, and reproducible. Whole blood glucose can be determined by this method with an error (CV) of less than 5%.

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