Design and catalytic studies of structural and functional models of the catechol oxidase enzyme

The catechol oxidase activity of three copper/bicompartmental salen derivatives has been studied. One mononuclear, [CuL] (1), one homometallic, [Cu2L(NO3)2] (2), and one heterometallic, [CuMnL(NO3)2] (3) complexes were obtained using the ligand H2L = N,N'-bis(3-methoxysalicylidene)-1,3-propaned...

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Detalles Bibliográficos
Autores: Terán More, Aaron, Jaafar, Aida, Sánchez-Peláez, Ana Edilia, Torralba, Maria del Carmen, Gutiérrez, Ángel
Tipo de recurso: artículo
Fecha de publicación:2020
País:España
Institución:Universidad Complutense de Madrid (UCM)
Repositorio:Docta Complutense
Idioma:inglés
OAI Identifier:oai:docta.ucm.es:20.500.14352/88491
Acceso en línea:https://hdl.handle.net/20.500.14352/88491
Access Level:acceso abierto
Palabra clave:544.116
Biomimetic catalysis
Catalytic activity
Cu(II) complexes
Química inorgánica (Química)
2303.07 Compuestos de Coordinación
Descripción
Sumario:The catechol oxidase activity of three copper/bicompartmental salen derivatives has been studied. One mononuclear, [CuL] (1), one homometallic, [Cu2L(NO3)2] (2), and one heterometallic, [CuMnL(NO3)2] (3) complexes were obtained using the ligand H2L = N,N'-bis(3-methoxysalicylidene)-1,3-propanediamine through different synthetic methods (electrochemical, chemical and solid state reaction). The structural data indicate that the metal ion disposition models the active site of type-3 copper enzymes, such as catechol oxidase. In this way, their ability to act as functional models of the enzyme has been spectrophotometrically determined by monitorization of the oxidation of 3,5-di-tert-butylcatechol (3,5-DTBC) to 3,5-di-tert-butyl-o-benzoquinone (3,5-DTBQ). All the complexes show significant catalytic activity with ratio constants (kobs) lying in the range (223-294) × 10-4 min-1. A thorough kinetic study was carried out for complexes 2 and 3, since they show structural similarities with the catechol oxidase enzyme. The greatest catalytic activity was found for the homonuclear dicopper compound (2) with a turnover value (kcat) of (3.89 ± 0.05) × 106 h-1, which it is the higher reported to date, comparable to the enzyme itself (8.25 × 106 h-1).