Hydrogen Peroxide Helps in the Identification of Monophenols as Possible Substrates of Tyrosinase
| Autor: | Mary of the Sea GARCÍA-MOLINA, Joseph Luis MUÑOZ-MUÑOZ, Joseph BERNA, Joseph Neptune RODRÍGUEZ-LÓPEZ, Ramón VARÓN, Francis GARCÍA-CÁNOVAS |
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| Rok vydání: | 2013 |
| Předmět: |
Tyrosinase
chemistry.chemical_element Hydroxylation Applied Microbiology and Biotechnology Biochemistry Substrate Specificity Analytical Chemistry chemistry.chemical_compound Phenols Oxidation state Organic chemistry Enzyme Inhibitors Hydrogen peroxide Molecular Biology chemistry.chemical_classification Monophenol Monooxygenase Organic Chemistry Substrate (chemistry) Hydrogen Peroxide General Medicine Copper Enzyme chemistry Catalytic cycle Molecular oxygen Agaricales Oxidation-Reduction Protein Binding Biotechnology |
| Zdroj: | Bioscience, Biotechnology, and Biochemistry. 77:2383-2388 |
| ISSN: | 1347-6947 0916-8451 |
| Popis: | Tyrosinase exists in three forms in the catalytic cycle depending on the oxidation state of the copper: met- (Em), oxy- (E(ox)), and deoxy- (Ed). When O-quinones, products of the enzymatic reaction, evolve chemically to generate an O-diphenol in the reaction medium, the enzyme acts on a monophenol with O-diphenol as reductant, converting Em to Ed. The binding of Ed to molecular oxygen gives E(ox), which is active on monophenols, but when the O-quinone product does not generate O-diphenol through chemical evolution, the monophenol does not act as an enzyme substrate. The fact that E(ox) can be formed from Em with hydrogen peroxide can be used to help identify whether a monophenol is a substrate of tyrosinase. The results obtained in this study confirm that compounds previously described as inhibitors of the enzyme are true substrates of it. |
| Databáze: | OpenAIRE |
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