J. Am. Soc. Brew. Chem. 72(1):30-35, 2014 Ascorbic acid oxidase (AAO) develops in the embryo tissues of barley during steeping and initial stages of germination. Two AAO enzymes have been identified. One of them is of remarkably low molecular weight (<10,000). Both are very heat tolerant and capable of acting over a broad pH range. Both enzymes would be expected to function during conversion te...

Ascorbate oxidase from pumpkin (Cucurbita sp.) was purified from a commercially available preparation. A single polypeptide band with M(r) 64,000 was detected after sodium dodecylsulfate-polyacrylamide gel electrophoresis of the purified enzyme. In double immunodiffusion tests, antiserum against the purified preparation formed a single precipitin line with the crude extract from pumpkin fruit t...

Objective—To determine the roles of nitric oxide synthase (NOS) and NADPH oxidase in the impairment of capillary blood flow in sepsis and in the reversal of this impairment by ascorbate. Design—Prospective, controlled laboratory study. Setting—Animal laboratory in research institute. Subjects—Adult male wild type (WT), nNOS−/−, iNOS−/−, eNOS−/−, and gp91phox−/−mice. Interventions—Sepsis was ind...

cDNA clones for ascorbate oxidase were isolated from a cDNA library made from cucumber (Cucumis sativus) fruit mRNA. The library was screened with synthetic oligonucleotides that encode the NH2-terminal sequence of this enzyme. Nucleotide sequence analysis of the cloned cDNA inserts revealed a 1761-base-pair open reading frame that encoded an NH2-terminal signal peptide of 33 amino acids and a ...

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...

UNLABELLED The thermal stability of vitamin C (including l-ascorbic acid [l-AA] and dehydroascorbic acid [DHAA]) in crushed broccoli was evaluated in the temperature range of 30 to 90 degrees C whereas that of ascorbic acid oxidase (AAO) was evaluated in the temperature range of 20 to 95 degrees C. Thermal treatments (for 15 min) of crushed broccoli at 30 to 60 degrees C resulted in conversion ...

Oxidative conversion of 5-hydroxymethylfurfural (HMF) is of biotechnological interest for the production of renewable (lignocellulose-based) platform chemicals, such as 2,5-furandicarboxylic acid (FDCA). To the best of our knowledge, the ability of fungal aryl-alcohol oxidase (AAO) to oxidize HMF is reported here for the first time, resulting in almost complete conversion into 2,5-formylfuranca...

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...