Tomato Peroxidase: Purification, Characterization, and Catalytic Properties 1
AUTOR(ES)
Kokkinakis, Demetri M.
RESUMO
A major peroxidase has been found in the tomato pericarp (Lycopersicon esculentum var. Tropic) of the ripe and green fruit. A purification scheme yielding this enzyme approximately 85% pure has been developed. The tomato enzyme resembles horseradish peroxidase (HRP) in a standard peroxidase assay and in its ability to be reduced to ferroperoxidase, to be converted to oxyferroperoxidase (compound III), and to form peroxidase complexes with hydrogen peroxide (compounds I and II). In contrast to the HRP, the tomato peroxidase fails to catalyze the aerobic oxidation of indole-3-acetic acid in the presence of 2,4-dichlorophenol and manganese. The tomato peroxidase can be resolved into two nonidentical subunits in the presence of dithiothreitol while HRP remains as a single polypeptide chain after such treatment. Dithiothreitol is oxidized in the presence of tomato or horseradish peroxidase with the enzymes accumulating in their oxyferroperoxidase forms during the oxidation reaction. Whereas HRP returns to its free ferric form at the end of the reaction, the tomato enzyme is converted into a form that absorbs at 442 nanometers.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=542772Documentos Relacionados
- Purification, characterization, and immunological properties of fumarase from Euglena gracilis var. bacillaris.
- Lignin-degrading enzyme from Phanerochaete chrysosporium: Purification, characterization, and catalytic properties of a unique H2O2-requiring oxygenase
- Wheat Alcohol Dehydrogenase Isozymes: PURIFICATION, CHARACTERIZATION, AND GENE EXPRESSION 1
- Purification, Properties, and Distribution of Ascorbate Peroxidase in Legume Root Nodules 1
- Purification, characterization, and properties of an aryl aldehyde oxidoreductase from Nocardia sp. strain NRRL 5646.