A Novel Enzyme,L -Tryptophan Oxidase, from a Basidiomycete,Coprinussp. SF-1: Purification and Characterization
| Autor: | Kazue Ito, Yuji Furuya, Yoshikazu Izumi, Takashi Ohshiro, Toshikatsu Hirahara, Hidemi Sawada |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Oxygenase
Decarboxylation Stereochemistry Coprinus Applied Microbiology and Biotechnology Biochemistry Absorption Substrate Specificity Analytical Chemistry Enzyme Stability Molecular Biology chemistry.chemical_classification Oxidase test biology Molecular mass Chemistry Organic Chemistry Temperature Tryptophan Oxidative deamination General Medicine Hydrogen-Ion Concentration biology.organism_classification Molecular Weight Enzyme Metals Salts Oxidoreductases Oxidation-Reduction Biotechnology |
| Zdroj: | Bioscience, Biotechnology, and Biochemistry. 64:1486-1493 |
| ISSN: | 1347-6947 0916-8451 |
| DOI: | 10.1271/bbb.64.1486 |
| Popis: | A basidiomycete, Coprinus sp. SF-1, was found to produce an L-Trp-oxidizing enzyme by screening from the culture collection of our laboratory. After solubilization by 1 M NaSCN from the particulate fraction of disrupted cells of the strain, the enzyme was purified about 76-fold to essential homogeneity. The enzyme had a molecular mass of about 420 kDa and the subunit molecular mass was 68 kDa. The enzyme contained 1 mol of non-covalently bound FAD per mol of the subunit. It catalyzed the simultaneous reactions of oxidative deamination and oxygenative decarboxylation of L-Trp to form indolepyruvic acid and indole-3-acetamide, the former of which was further oxidized to indole-3-acetic acid. The molar ratio of the respective reaction products was about 9:1. The enzyme specifically oxidized L-Trp, and slightly acted on L-Phe and L-Tyr. The Km for L-Trp was about 0.5 mM in both oxidase and oxygenase reactions. Thus, the enzyme is a novel one and was tentatively designated "L-Trp oxidase (deaminating and decarboxylating)". The optimum pHs of oxidase and oxygenase activities were 7.0 and 9.0, respectively. The optimum temperatures of both activities were 50 degrees C. The enzyme was stable at pH 6.0-10.5 and below 50 degrees C, and at 4 degrees C for 1 year. |
| Databáze: | OpenAIRE |
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