1-Aminocyclopropane-1-carboxylic acid (ACC) oxidase (ACCO) catalyses the final step in ethylene biosynthesis converting ACC to ethylene, cyanide, CO2, dehydroascorbate and water with inputs of Fe(II), ascorbate, bicarbonate (as activators) and oxygen. Cyanide activates ACCO. A 'nest' comprising several positively charged amino acid residues from the C-terminal α-helix 11 along with Lys158 and A...

The electron spin resonance (ESR) spectrum of erythrocytes of a health male volunteer exhibited 2 min after intravenous administration of 1g of ascorbic acid a considerable increase in spin concentration and an new signal at about g-2.005 which we previously had found to correlate to the semidehydroascorbate (SDA) radical and which is not identical with the O2 radical. Moreover, the vitamin C c...

Humans are unable to synthesise ascorbate (Vitamin C) due to the lack of a functional gulonolactone oxidase (Gulo), the enzyme that catalyses the final step in the biosynthesis pathway. Ascorbate is a vital micronutrient required for many biological functions, including as a cofactor for metalloenzymes that regulate the transcription factor hypoxia-inducible factor-1 (HIF-1), which governs cell...

Ascorbate (vitamin C) is found in high concentrations in the striatum in which it may play a role in behavioral activation. To test this hypothesis, freely behaving rats received bilateral intrastriatal infusions of ascorbate oxidase (AAO) to inactivate extracellular ascorbate. Slow-scan voltammetry was used simultaneously to assess changes in ascorbate and 3,4-dihydroxyphenylacetic acid (DOPAC...