Oxidation of indole-3-acetic acid by dioxygen catalysed by plant peroxidases: specificity for the enzyme structure
| Autor: | Vladimir I. Tishkov, P.A. Savitsky, Irina G. Gazaryan, Lo Gorton, L. M. Lagrimini, Tautgirdas Ruzgas |
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| Rok vydání: | 1999 |
| Předmět: |
Hemeproteins
Models Molecular Protein Conformation Molecular Sequence Data Receptors Cell Surface Biochemistry Catalysis Fungal Proteins Structure-Activity Relationship chemistry.chemical_compound Plant Growth Regulators Catalytic Domain Amino Acid Sequence Molecular Biology Chromatography High Pressure Liquid Conserved Sequence Plant Proteins chemistry.chemical_classification Indoleacetic Acids biology Chemistry Cytochrome c peroxidase fungi food and beverages Substrate (chemistry) Hydrogen Peroxide Cell Biology Lignin peroxidase Hydrogen-Ion Concentration Plants Oxidants Enzyme structure Amino acid Oxygen Kinetics Peroxidases biology.protein Indole-3-acetic acid Oxidation-Reduction Research Article Peroxidase |
| Zdroj: | Biochemical Journal. 340:579-583 |
| ISSN: | 1470-8728 0264-6021 |
| DOI: | 10.1042/bj3400579 |
| Popis: | Indole-3-acetic acid (IAA) can be oxidized via two mechanisms: a conventional hydrogen-peroxide-dependent pathway, and one that is hydrogen-peroxide-independent and requires oxygen. It has been shown here for the first time that only plant peroxidases are able to catalyse the reaction of IAA oxidation with molecular oxygen. Cytochrome c peroxidase (CcP), fungal peroxidases (manganese-dependent peroxidase, lignin peroxidase and Arthromyces ramosus peroxidase) and microperoxidase were essentially inactive towards IAA in the absence of added H2O2. An analysis of amino acid sequences allowed five structurally similar fragments to be identified in auxin-binding proteins and plant peroxidases. The corresponding fragments in CcP and fungal peroxidases showed no similarity with auxin-binding proteins. Five structurally similar fragments form a subdomain including the catalytic centre and two residues highly conserved among ‘classical’ plant peroxidases only, namely His-40 and Trp-117. The subdomain identified above with the two residues might be responsible for the oxidation of the physiological substrate of classical plant peroxidases, IAA. |
| Databáze: | OpenAIRE |
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