The involvement of cytochrome b561, an integral membrane protein, in electron transfer across chromaffin-vesicle membranes is confirmed by changes in its redox state observed as changes in the absorption spectrum occurring during electron transfer. In ascorbate-loaded chromaffin-vesicle ghosts, cytochrome b561 is nearly completely reduced and exhibits an absorption maximum at 561 nm. When ferri...

a completely randomized design (crd) with three replications was conducted at greenhouse of urmia university in 2013 to study the effect of different methyl jasmonate concentrations (0, 0.1 and 0.5 mm) on the activity of enzymes polyphenol oxidase, phenylalanine ammonia lyase, catalase, ascorbate peroxidase, guaiacol peroxidase and total protein content in basil. activity of the enzymes and tot...

The thermostabilization of some enzymes by amidination with dimethylsuberimidate was surveyed. In the enzymes investigated, a moderate increase of thermostability in glucose oxidase and invertase, and prominent increase in lactate dehydrogenase, alcohol dehydrogenase and ascorbate oxidase were observed. The increase of thermostability by amidination was suggesting the synergism of the enhanceme...

trehalose is an important disaccharide signal metabolite in plants which is involved in various aspects of plant function such as response to stress, photosynthesis and carbon allocation and partitioning. a mutant of arabidopsis lacking trehalose-6-phosphate synthase activity (tps1) accumulates ascorbate. exogenous ascorbate application ameliorates trehalose induced growth inhibition of wild ty...

cision is not better than 2% of the maximum concentration of each concentration range. This means that an error of 0.02 mg/L S in the 0-1 mg/L S range corresponds to an error of 1 mg/L S in the 0-50 mg/L S range. For optimum precision, the response of the analyzer should be kept large by selecting the syringe size according to the sulfur content of the analyte and maintaining a reasonably rapid...

The electrochemistry of some copper-containing proteins and enzymes, viz. azurin, galactose oxidase, tyrosinase (catechol oxidase), and the "blue" multicopper oxidases (ascorbate oxidase, bilirubin oxidase, ceruloplasmin, laccase) is reviewed and discussed in conjunction with their basic biochemical and structural characteristics. It is shown that long-range electron transfer between these enzy...

We describe a rapid kinetic glucose oxidase (EC 1.1.3.4) procedure for quantifying glucose. Glucose oxidase concentration was reduced from the more usual 20 kU/L to 4 kU/L, and pH was reduced from 7.0 to 6.6. Potassium ferrocyanide (20 mumol/L) and ascorbate oxidase (1 kU/L) were incorporated in the procedure. The assay results vary linearly with glucose concentration from 0 to 50 mmol/L and ar...

introduction plant responses to environmental stress have a central role in agricultural production. responses results from events occurring at all levels of the organization, from biochemical reactions in cells to whole plant physiology. many plants are injured when exposed to low non-freezing temperatures. however, data on the effects of night temperatures are scarce. on the other hand, nitri...