Although many vertebrates can synthesize ascorbic acid (vitamin C), it is still unclear from the evolutionary perspective when the ability to synthesize the vitamin first appeared in the animal kingdom and how frequently the trait has been lost. We report here ascorbic acid biosynthesis ability in sea lamprey (Petromyzon marinus) which represent the most ancient vertebrate lineage examined thus...

Humans lack the ability to synthesize vitamin C (ascorbate) due to the absence of gulonolactone oxidase, the last enzyme in the biosynthetic pathway in most other mammals. The corresponding oxidoreductase in trypanosomes therefore represents a target that may be therapeutically exploitable. This is reinforced by our observation that Trypanosoma cruzi, the causative agent of Chagas' disease, lac...

A genomic clone encoding ascorbate oxidase was isolated from pumpkin (Cucurbita sp.). This gene is consisted of four exons and three introns. Analyses of the promoter fusion to beta-glucuronidase reporter gene by transient expression assay in pumpkin fruit tissues suggested the existence of a cis-acting region responsible for auxin regulation.

ligation states Preparations of cytochrome-c oxidase (EC 1.9.3.1) isolated from bovine heart are usually heterogeneous. They can be considered as mixtures of two forms of the enzyme, ‘slow’ and ‘fast’, which differ considerably in their properties. Until recently preparations consisted mainly of ‘slow’ (‘resting’) oxidase. In this form haem a3 is entirely high spin, reacts slowly with cyanide a...

Abbreviations: 2,4-D: 2,4-dichlorophenoxyacetic acid ABA: abscisic acid ABI3: ABI gene family member 3 ANP1: Arabidopsis NPK1-like protein kinase AP: ascorbate peroxidase AOX: alternative oxidase DNA: deoxyribonucleic acid Fe-EDTA: ferric ethylenediaminetetraacetic acid M: molar concentration MAPK: mitogen-activated protein kinase NO: Nitric oxide PGRs: plant growth regulators ROS: reactive oxy...

Most cells that have been tested have two trans plasma membrane electron transport systems for the oxidation of cytosolic NADH. The first is an oxidase which transfers electrons from NADH to oxygen through dehydrogenases to coenzyme Q and a terminal reduced coenzyme Q oxidase. The second system for trans membrane electrontransport from NADH is a protein complex called porin or Voltage Dependent...

A Myceliophthora thermophila laccase and a Rhizoctonia solani laccase were mutated on a pentapeptide segment believed to be near the type-1 Cu site. The mutation L513F in Myceliophthora laccase and the mutation L470F in Rhizoctonia laccase took place at a position corresponding to the type-1 Cu axial methionine (M517) ligand in Zucchini ascorbate oxidase. The triple mutations V509L,S510E,G511A ...

In many cancers, a chronic increase in oxidant stress - associated with elevated levels of hydrogen peroxide - contributes to the increased proliferative rate, diminished apoptosis, increased angiogenic and metastatic capacity, and chemoresistance that often characterize advanced malignancies. This oxidant stress often reflects up-regulation of expression and activity of NADPH oxidase, and/or d...