Molecular Dynamics Simulations on Aspergillus niger Monoamine Oxidase: Conformational Dynamics and Inter-monomer Communication Essential for Its Efficient Catalysis

Aspergillus niger Monoamine Oxidase (MAO-N) is a homodimeric enzyme responsible for the oxidation of amines into the corresponding imine. Laboratory evolved variants of MAO-N in combination with a non-selective chemical reductant represents a powerful strategy for the deracemisation of chiral amine...

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Detalles Bibliográficos
Autores: Curado Carballada, Christian, Feixas Geronès, Ferran, Osuna Oliveras, Sílvia
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2019
País:España
Institución:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositorio:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:recercat.cat:10256/23187
Acceso en línea:http://hdl.handle.net/10256/23187
Access Level:acceso abierto
Palabra clave:Biocatàlisi
Biocatalysis
Dinàmica molecular -- Simulació per ordinador
Molecular dynamics -- Computer simulation
Descripción
Sumario:Aspergillus niger Monoamine Oxidase (MAO-N) is a homodimeric enzyme responsible for the oxidation of amines into the corresponding imine. Laboratory evolved variants of MAO-N in combination with a non-selective chemical reductant represents a powerful strategy for the deracemisation of chiral amine mixtures and, thus, is of interest for obtaining chiral amine building blocks. As we reported recently, MAO-N presents a rich conformational dynamics with a flexible β-hairpin region that can adopt closed, partially closed and open states. Despite the β-hairpin conformational dynamics is altered along the laboratory evolutionary pathway of MAO-N, the connection between the β-hairpin conformational dynamics and how this affects active site catalysis still remains unclear. In this work, we use accelerated molecular dynamics to elucidate the potential interplay between the β-hairpin conformational dynamics and catalytic activity in MAO-N wild type (WT) and its evolved D5 variant. Our study reveals a delicate communication between both MAO-N monomers that impacts the active site architecture, and thus its catalytic efficiency. In both MAO-N WT and the laboratory evolved D5 variant, the β-hairpin conformation in one of the monomers affects the productive binding of the substrate in the active site of the other subunit. However, both MAO-N WT and D5 variants show a quite different behaviour due to the impact of distal mutations introduced experimentally with Directed Evolution on the conformational dynamics of the enzyme